The leafhopper species assemblages associated with native and replanted grasslands in southwest Montana by James Alexander Bess A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Entomology Montana State University © Copyright by James Alexander Bess (1997) Abstract: Leafhopper (Insecta: Homoptera: Cicadellidae) species assemblages were examined and compared between four distinct grassland types in southwestern Montana. Three sample sites (or patches) were chosen within each of the four grassland types (two native and two replanted), for a total of twelve sites. Leafhopper specimens were collected in sweepnet samples from each of the twelve sites in 1988 and 1991. The leafhopper assemblages from the twelve patches were compared using Spearman’s correlation analysis to determine which assemblages were most similar. In addition, cluster analyses, using Goodman-Kruskal’s Gamma coefficient, were performed to give a pictorial representation of spatial relationships between the assemblages and to compare with the correlation analyses. Analyses were performed on each individual years’ data and the combined data. The correlation analysis found the patches with each type to be closely related to one another, although some also correlated closely with patches from other types. Most of these between type associations were between the native grassland sites. Correlations were strongest using the combined data. Cluster analyses produced many spurious associations using the single years’ data that were unsubstantiated by patterns observed in the raw data. Cluster analysis of the combined data produced associations similar to those observed, with the correlation analysis and supported by the raw data. A total of 67 leafhopper taxa were identified during this study, 54 of which are new to Montana. THE LEAFHOPPER SPECIES ASSEMBLAGES
ASSOCIATED) WITH NATIVE AND REPLANTED
GRASSLANDS IN SOUTHWEST MONTANA
by
James Alexander Bess
A thesis submitted in partial fulfillment of the requirements for the degree
of
Master of Science
m
Entomology
MONTANA STATE UNIVERSITY-BOZEMAN Bozeman, Montana
May 1997 APPROVAL
of a thesis submitted by
James Alexander Bess
This thesis has been read by each member of the thesis committee and has been found to be satisfactory regarding content, English usage, format, citations, bibliographic style, and consistency, and is ready for submission to the College of Graduate Studies.
Kevin O ’Neill signature)
Approved for the Department of Entomology
Greg Johnson (Signature) Date
Approved for the College of Graduate Studies
R. L. Brown (Signature) Date STATEMENT OF PERMISSION TO USE
In presenting this thesis in partial fulfillment of the requirements for a master’s degree at Montana State University-B ozeman, I agree that the Library shall make it available to borrowers under the rules of the Library.
If I have indicated my intention to copyright this thesis by including a copyright notice page, copying is allowable only for scholarly purposes, consistent with “fair use” as prescribed in the U. S. Copyright Law. Requests for permission for extended quotation from or reproduction of this thesis in whole or in parts may be granted only by the copyright holder.
iii ACKNOWLEDGMENTS
I would like to thank my wife Karen for her invaluable assistance in the preparation of this document. Thanks also to Dr. Kevin O’Neill and Dr. William Kemp (both with the
Department of Entomology, Montana State University) for financial and technical assistance during my masters program. Ms. Catherine Seibert (Department of Biology,
Montana State University) has provided invaluable assistance with voucher specimen preparation and interpolation into the Montana State University Entomology Collection.
Mr. Jeffrey Holmes (Department of Entomology, Montana State University) collected and graciously provided the vegetation data used in this document. Mr. David Wachter
(Department of Entomology, Montana State University) provided invaluable assistance in the collection of many samples used for leafhopper-foodplant associations.
I would also like to thank Dr. Andy Hamilton (with Agriculture Canada) and Dr.
Ron Panzer (with Northeastern Illinois University) for their assistance in the determination of leafhopper specimens and leafhopper-host plant associations. Dr. Panzer also provided many useful editorial suggestions during my thesis preparation. Dr. Matthew Lavin
(Department of Biology, Montana State University) and Dr. Noel Pavlovic (with the U.S.
Geologic Survey at Indiana Dunes National Lakeshore) provided assistance in the preparation and interpretation of the statistical analyses used in this study. Finally I would like to thank Dr. Matthew Ayers and Dr, Roger Strand (at Dartmouth University) for their assistance in obtaining many of the references on leafhopper-habitat associations and their insightful comments during the preparation of this thesis. TABLE OF CONTENTS ACKNOWLEDGMENTS...... iv
LIST OF TABLES...... vii
LIST OF FIGURES...... viii
ABSTRACT...... ix
INTRODUCTION...... I Objectives...... ,...... 5 Hypotheses...... 5 MATERIALS AND METHODS...... 7 Selection of Patches...... 7 Sampling Techniques...... 9 Vegetation Sampling...... 9 Leafhopper Sampling...... 10 Specimen Identification...... 10 Vegetation...... :...... 10 Leafhoppers...... 11 Analysis...... 14 Correlation Analysis...... 14 Cluster Analysis...... 15 Descriptions of the Plant Assemblages and Patches...... 16 The Stipa comata/Bouteloua gracilis Association...... 16 The Festuca idahoensis/Agropyron spicatum Association...... 20 The Agropvron cristatum/Mfedicago sativa Association...... 22 The Bromus inermis/Medicago sativa Association...... 24 RESULTS...... 26 Leafhopper Species Collected...... 26 The Stipa comata/Bouteloua gracilis Association...... 26 The 1988 D a ta ...... 26 The Combined Data...... 32 The Festuca idahoensis/Agropyron spicatum Association...... 34 The 1988 D a ta ...... 34 The 1991 D a ta ...... 34 The Combined Data...... 35 The Agropyron cristatum/Medicago sativa Association...... 35 The 1988 D ata...... 35 The 1991 D a ta ...... 37 The Combined Data...... 37 The Bromus inermis/Medicago sativa Association...... 37 The 1988 D a ta ...... 37 The 1991 D a ta ...... 39 The Combined Data...... 39 RESULTS: A COMPARISON OF LEAFHOPPER ASSEMBLAGES IN DIFFERENT PATCHES...... 42 The 1988 D ata...... 42 The 1991 D ata...... 46 The Combined Data for 1988 and 1991...... 48 DISCUSSION...... 53 Similarity in Leafhopper Assemblages between Sites...... 53 Correlation between Leafhopper Species Abundance and Percent Cover of Know Host Plants...... 54 Aceratagallia spp...... 54 Amblvsellus grex...... 56 Athysanus argentarius...... 56 Chlorotettix unicolor...... 56 Diplocolenus confieuratus...... 57 Doratura stvlata...... 58 Dorvcephalus platyrhynchus...... 58 Endria inimica...... 58 Flexamia abbreviatta and F. flexulosa...... 59 Hecalus spp...... 59 Latalus missellus...... 60 Orocastus labeculus and 0. perpusilus...... 60 Conclusions Concerning Leafhopper/Host Plant Associations...... 61 Leafhopper Taxa occurring Primarily in the Native Plant Assemblages...... 61 Leafhopper Taxa occurring Primarily in the Replanted Plant Assemblages...... 63 Leafhopper Taxa with Wide Distributions in the Gallatin Valley (but no well-defined plant assemblage or host plant preferences)...... 65 Notes on the Rarer Leafhopper Species Recorded in this Study...... 66 Notes on Some of the Pooled Leafhopper Genera...... 69 SAMPLING EFFORT AND ADDITIONS TO THE LEAFHOPPER FAUNA OF M ONTANA...... 71 Sampling Effort...... ;...... 71 Additions to the Leafhopper Fauna of Montana...... 74 SUMMARY...... 76
BIBLIOGRAPHY...... 78 APPENDIX A: 1988 AND 1991 LEAFHOPPER PHENOLOGY DATA FOR THE TWELVE PATCHES...... ■...... 84 APPENDIX B: THE LEAFHOPPER SPECIES COLLECTED DURING THIS STUDY...... 93
vi ------. . . I-. L . , I , ii.i_i_ J i i i . : I I :n / 'I ' I
LIST OF TABLES
TABLE I. Elevation, Precipitation, and Cover Data for the Sample Patches: Gallatin County, Montana (1991)...... 8
TABLE 2. Plant Species Frequency and Percent Cover at the Native Habitat Patches (1991 Data)...... 17-18
TABLE 3. 1988 Leafhopper Species Abundance Data from the Twelve Patches...... 27
TABLE 4. 1991 Leafhopper Species Abundance Data from the Twelve Patches...... 28
TABLE 5. Leafhopper Abundance Data by Plant assemblage (1988-1991 combined data)...... 29
TABLE 6. Leafhopper Abundance Data for the Twelve Patches (1988/1991 Combined)...... 30
TABLE 7. Leafhopper Species Richness by Subfamily and Plant assemblage...... 31
TABLE 8. Spearman’s Correlations in Leafhopper Species Abundance between the Twelve Patches (1988 Data)...... 43
TABLE 9. Spearman’s Correlations in Leafhopper Species Abundance between the Twelve Patches (1991 Data)...... 47
TABLE 10. Spearman’s Correlations in Leafhopper Species Abundance between the Twelve Patches (1988/1991 Combined Data)...... 49
TABLE 11. Correlation Between Leafhopper Species Abundance and Percent Cover for Eleven Plant Species...... 55
TABLE 12. The Leafhopper Fauna of Montana...... 75
vii LIST OF FIGURES
FIGURE I. Leafhopper Species Relative Abundance - STCO/BOGR Grasslands (1988 - 1991 combined)...... 33
FIGURE 2. Leafhopper Species Relative Abundance - FEID/AGSP Grasslands (1988 - 1991 combined)...... 36
FIGURE 3. Leafhopper Species Relative Abundance - Agcr/Mesa Grasslands (1988 - 1991 combined)...... 38
FIGURE 4. Leafhopper Species Relative Abundance - Brin/Mesa Grasslands (1988 - 1991 combined)...... 40
FIGURE 5. Cluster Analysis of the 1988 Leafhopper Data from the Twelve Patches...... 45
FIGURE 6. Cluster Analysis of the 1991 Leafhopper Data from the Twelve Patches...... ;...... 50
FIGURE 7. Cluster Analysis of the Combined Leafhopper Data from the Twelve Patches...... 52
Vlll THE LEAFHOPPER SPECIES ASSEMBLAGES ASSOCIATED WITH NATIVE AND REPLANTED GRASSLANDS IN SOUTHWEST MONTANA James Alexander Bess, 1997
ABSTRACT
Leafhopper (Insecta: Homoptera: Cicadellidae) species assemblages were examined and compared between four distinct grassland types in southwestern Montana. Three sample sites (or patches) were chosen within each of the four grassland types (two native and two replanted), for a total of twelve sites. Leafhopper specimens were collected in sweepnet samples from each of the twelve sites in 1988 and 1991. The leafhopper assemblages from the twelve patches were compared using Spearman’s correlation analysis to determine which assemblages were most similar. In addition, cluster analyses, using Goodman- Kruskal’s Gamma coefficient, were performed to give a pictorial representation of spatial relationships between the assemblages and to compare with the correlation analyses. Analyses were performed on each individual years’ data and the combined data. The correlation analysis found the patches with each type to be closely related to one another, although some also correlated closely with patches from other types. Most of these between type associations were between the native grassland sites. Correlations were strongest using the combined data. Cluster analyses produced many spurious associations using the single years’ data that were unsubstantiated by patterns observed in the raw data. Cluster analysis of the combined data produced associations similar to those observed, with the correlation analysis and supported by the raw data. A total of 67 leafhopper taxa were identified during this study, 54 of which are new to Montana. INTRODUCTION
Kemp et al. (1990) observed that grasshopper (Orthoptera: Acrididae) species in Gallatin
County, Montana were distributed non-randomly across grassland sites characterized by different plant assemblages. Despite variation in grasshopper and plant community composition among patches within plant assemblages, certain species of grasshoppers tended to be restricted to xeric, lower elevation sites at the west end of the valley, while others showed an affinity for more mesic, higher elevation sites at the east end. A third group of species was more widely distributed, displaying relatively high abundance across the entire valley. These results were confirmed and expanded by Wachter (1995), who also surveyed the grasshopper communities associated with grasslands in the Bridger and Hyalite Mountain ranges of Gallatin County. Similar evidence for uneven distribution of grasshopper species across habitats has been reported elsewhere in North
America (Alexander and Hilliard, 1969; Blatchley, 1920; Cantrall, 1943; Evans, 1988; Fielding and Brusven, 1993, 1995; Joem, 1979, 1982; Mulkern, 1967; Otte, 1981,1984).
Although grasshoppers are often abundant (and sometimes economically important) herbivores in grassland habitats, leafhoppers (Homoptera: Auchenorrhyncha: Cicadellidae) are commonly considered the dominant herbivorous insects in temperate grassland ecosystems, in terms of density of individuals and diversity of species (Cherrill and Rushton, 1993; Waloff, 1973;
Waloff and Solomon, 1972). Studies in Europe and North America have shown that leafhopper species also exhibit preferential habitat selection.
In England and Europe, numerous studies have been conducted to determine the effects of variation in environmental parameters on the composition of grassland leafhopper assemblages
(Brown, et al., 1992; Morris, 1973, 1981a-b,1990a-b; Novotny, 1994a-b, 1995; Waloff, 1980; WalofF and Solomon, 1972). These studies can be grouped into four categories: I) effects of land management practices (i.e. grazing, mowing or fertilizing); 2) effects o f soil pH; 3) effects o f plant species composition; and 3) effects of habitat successional age.
In studies of grazing effects, Brown et al. (1992) found that the composition of leafhopper assemblages on sheep-grazed calcareous grasslands was strongly affected by plant architecture, as dictated by the particular grazing regime being implemented. Morris (1973) also reported grazing effects on the composition of leafhopper assemblages in British grasslands, particularly with reference to the timing of the grazing event (i.e. spring vs. fall grazing). In addition, ungrazed grasslands contained a greater number of leafhopper individuals and species, when compared with grazed sites. As with Brown et al., Morris believed grassland structure (especially vegetation height) was a driving force in determining the composition of leafhopper assemblages.
Morris (1981a-b, 1983), in studies of the calcareous grasslands of England, observed that cutting of vegetation during the height of the growing season (i.e. July) had a significant deleterious effect on many leafhopper species. Mowing in the spring (May) had a less significant effect of shorter duration, being confined mainly to species that reached the adult stage in early summer. The effects of the July cutting persisted through winter and into spring, especially in species that overwinter as adults. Progressive declines were observed in many species over the course of a three year study (1973-1975), especially on the plots cut in July. Like Brown and associates (1992), Morris observed a greater number of leafhoppers on grasslands that were not intensively managed.
Waloff (1980) and Waloff and Solomon (1972) compared the leafhopper fauna of acidic and calcareous grasslands, noting that some leafhopper species were shared between the two
2 habitats, but in differing proportions. Despite these similarities, there were several leafhopper
species reported only from a single grassland type. Morris (1990a-b), in studies of leafhopper.
colonization in newly sown calcareous grasslands, observed that the leafhopper fauna of these
early successional grasslands was dominated by several wide ranging, multivoltine habitat generalists; with very few of the rarer, univoltine species characteristic of more mature, semi natural grasslands. Morris concluded that habitat structure, habitat age, and proximity to adjacent natural grasslands were as important as plant species composition in the determination of leafhopper assemblages. Brown et al. (1992) also noted that the composition of leafhopper assemblages varied greatly between early successional and older, more stable grassland communities. Much of this variation was attributed to the absence of specific food plants in the early successional habitats. These plants appeared to require old, relatively undisturbed native grasslands for survival, thus limiting the distribution of their associated leafhoppers.
Novotny (1994a-b; 1995), in studies on the grasslands of central Europe, found that the majority of leafhopper species occurring in ruderal, early successional habitats tended to have wider ranges of host plant use than species occurring in older, more stable environments. He also observed that host plant specialization became more prevalent with successional age of the habitat and that many of these specialist species showed poor dispersal capabilities. Leafhoppers that feed on early successional plant species were also found to have greater dispersal capabilities, wider ranges of host plant usage, larger geographic distributions and produced a greater number of generations per year than those feeding on more competitive, stress-tolerant plants.
Although age, management history and structure of grassland plant assemblages has been shown to have a deterministic effect on resident leafhopper assemblages, the distribution of many
3 species appears to be associated with the distribution of their host plants (Brown et al., 1992;
Buntin3 1988; Cherrill and Rushton3 1993; Claridge and Wilson, 1978; Gardner and Usher3 1989;
Genung and Mead3 1969; Hicks and Whitcomb, 1996; Nagel, 1979; Novotny3 1994a-b, 1995;
Prestidge and McNeill, 1983; Teraguchi3 1986; WalofFand Thompson3 1980; Whitcomb et al.,
1986, 1987a-b, 1994).
In North America, Whitcomb and associates have conducted numerous studies of the grassland leafhopper fauna’s of the Great Plains and Chihuahuan Desert regions (Hicks and
Whitcomb, 1996; Whitcomb et al., 1986, 1987a-b; 1994). Their studies have focused on three of the most species-rich grassland genera in North America; Athysanella: Flexamia and
Laevicephalus. Their results suggest that the distribution of these leafhoppers is closely associated with the distribution of their host plants, although many do not occur throughout the range of their host. This non-random distribution within the range of their hosts indicates that additional factors are limiting their ability to colonize sites. Therefore, specific grassland types, while they may have plant species in common with other types, often contain unique leafhopper assemblages adapted to a specific set of local environmental parameters.
Because of their role as the dominant insect herbivores in grassland habitats and their apparent sensitivity to variations in their local environment, leafhoppers are good subjects for studying the relationship between insect species distribution and plant community composition.
The focus of the current study was to determine if the leafhopper species occurring in Gallatin
County, Montana sorted into relatively discrete groupings according to plant assemblage, as was observed in the local grasshopper fauna (Kemp et al., 1990). In addition, I wanted to determine if there were significant differences in leafhopper species composition and relative abundance
4 between native and replanted grasslands within the same plant assemblage. As a final objective, I wanted to update the list of leafhopper species in Montana previously compiled by Fox (1924).
Objectives
The goal of my research was to identify the leafhopper (Homoptera: Cicadellidae) species assemblages associated with four distinct grassland types (following Mueggler and Stewart, 1980) in Gallatin County, Montana. Specific objectives of this project were to:
1. determine if there are distinct leafhopper species assemblages associated with the
four plant assemblages (two native, two replanted);
2. determine if the abundance of selected leafhopper species varies with changes in
percent cover of known or suspected host plants; and
3. determine which (if any) leafhopper species are restricted in occurrence to native
grassland patches.
Hypotheses
My first hypothesis is that discrete assemblages of leafhopper species will be associated with each of the four plant assemblages. The null hypothesis would be that leafhopper species are randomly distributed among the plant assemblages.
My second hypothesis is that the distribution of leafhoppers will be dependent on the distribution of their known or suspected host plants. The null hypothesis is that leafhopper species distribution is unrelated to the distribution of their host plants.
5 My third hypothesis is that some of the leafhopper species recorded will occur only (or most abundantly) in the native habitat patches within a particular habitat region. The null hypothesis would be that leafhopper species are evenly distributed between native and replanted grasslands within the same habitat region.
6 MATERIALS AND METHODS
The vegetation data were collected as part of rangeland grasshopper studies being conducted by Dr. William P. Kemp and associates at Montana State University. The leafhopper specimens used in the present study were collected in sweep net samples used in the above- mentioned grasshopper research (Kemp et al., 1990). Throughout this thesis, the terms “patch” and “site” refer to a defined area within which leafhopper and plant data were collected. Each patch contained a distinct plant assemblage previously determined by Kemp et al. (1990).
Selection of Patches
Two primary plant assemblages were selected for this study, the Stipa comata Trin. &
Rupr./Bouteloua gracilis (H.B.K.) (STCO/BOGR) and Festuca idahoensis Elmer/Agropvron spicatum (Pursh) (FEID/AGSP) associations of Mueggler and Stewart (1980). These represent dry and mesic grassland types, respectively, and occur along an elevation and precipitation gradient from 1236 m elevation at Three Forks, (annual precipitation 25-3Ocm), to 1750 m at the base of the Bridger Mountains (annual precipitation 40-5 Ocm), Gallatin County, Montana
(longitudes l l l o00'-lll°40' east-west, latitudes 46°00'-45°45') (Table I). Two replanted associations were also studied, the Agropvron cristatum (L.VMedicago sativa L. (AgcryMesa) and Bromus inermis Levss/Medicago sativa L. (BrinM esa) associations. The replanted
AgcrM esa stands occur within the same elevation and precipitation zone as the native
STCO/BOGR grasslands and the replanted BrinM esa stands occur within the same zone as the native FEID/AGSP grasslands.
7 Table I. Elevation, Precipitation, and Cover Data for the Sample Patches: Gallatin Co., Montana (1991).
Plant Mean Annual Assemblage Elevation (m) Precipitation (cm)1 % Grass Cover % Forb Cover % Bare Ground STCO/BOGR (all patches) ,200-140« 20-35 54.50 (mean) 11.10 (mean) 16 20 finnan) 7A - - 50.96 20.41 23.88 IOA - - 50.21 4.36 10.83 16A -- 62.37 8.39 13.75 FEID/AGSP (all patches) 1400 - 2300 35-50 34.00 (mean) 36.90 (mean) 6.70 (mean) 21A -- 31.33 30.61 6.78 25A - - 35.48 30.63 2.7 26A - - 35.17 49.42 10.63 Agcr/Mesa (all patches) 1200-1400 20-35 38.00 (mean) IKHmem, 28.00 (mean, Tb -- 31.69 1.57 16.25 16b - - 50.96 6.33 35.25 17b -- 30.41 0.85 34.03 Brin/Mesa (all patches) 1400 - 2300 35 - 50 57.00 (mean) 8.50 (mean) 32.00 (mean) 21b - - 23.53 18.36 25.14 25b - - 67.98 1.09 35.25 26b - - 79.24 6.02 34.03
1 Information on precipitation in these Plant Assemblages is taken from Mueggler and Stewart, 1980. Twelve patches (3 in each of the 4 plant assemblages) were chosen for use in this study.
Patch selection was based on a Detrended Correspondence Analysis (DCA) of vegetation characteristics as outlined in Kemp et al. (1990). Three patches within each of the two native plant assemblages, (STCOZBOGR) and (FEID/AGSP), were selected because of their close similarities (within assemblage) in plant species composition, precipitation, and elevation (i.e. they had similar coordinates in the DC A). These native plant assemblages were chosen because they occurred at opposite ends of a precipitation and elevation gradient for Gallatin County. Three patches in each of the two replanted plant assemblages, (AgciVMesa) and (Brin/Mesa), were chosen using the same criteria. For comparisons between native and replanted patches within a habitat zone, patches were always adjacent. In order to minimize edge effect, sampling was restricted to the center of each patch, avoiding the border between adjacent patches. The minimum size of any one patch was 10 hectares and no two distinct native patches shared a common border.
Sampling Techniques
Vegetation Sampling
The vegetation within each of the four plant assemblages was sampled during July and
August of 1991 to coincide with peak standing cover of plants (Kemp et al., 1990). Forty 0.10 m2 (20 x 50 cm) quadrats were sampled along a randomly selected transect at each of the twelve patches. Within each quadrat, percent canopy cover of each plant species, litter, moss/lichen, and bare ground were estimated in 5% increments following the methods described by Daubenmire
9 (1959). Subsequent analyses were based on mean cover-estimates of plant species over all
quadrats in a patch, as was done in previous studies (Kemp et al., 1990).
Leafhopper Sampling
Sweep nets were used to sample leafhopper populations. Samples were collected at each of the twelve patches and consisted of 200, 180 degree sweeps through vegetation with a 15 inch diameter net, as described by Kemp et al. (1990). In 1988, samples were collected three times per year in late May/June, late July,.and late August (Appendix A). In 1991, an additional September collection was included to sample the fall leafhopper fauna (Appendix A). All sweep samples were collected between 0930 and 1600 h, under sunny skies (<15% cloud cover) and light winds
(<38 kph). Leafhopper samples were placed either in alcohol (the 1988 samples) or air dried (the
1991 samples). Samples were collected in 1988 and 1991, years of very poor and fairly normal rainfall conditions, respectively. These years were selected to gather the greatest possible array of leafhopper species, as these insects are known to vary in abundance depending on seasonal rainfall
(Waloff, 1973; Whitcomb et al., 1994).
Specimen Identification
Vegetation
Jeffrey Holmes (with USDA-ARS Rangeland Entomology Laboratory at Montana State
University) identified all plant specimens observed during the vegetation studies. Plant specimens that could not be identified in the field were returned to the lab for analysis and comparison with voucher specimens in the Montana State University Herbarium. Most of the early spring
10 ephemeral genera such as Besseya. Ervthronium. Fritillaria. Dodecatheon. and Delphinium are conspicuously absent from the species list in Table 2. This is a result of vegetation surveys being conducted in mid-summer (to gather information during peak standing cover), when most of these spring and early summer species had senesced.
One specific taxonomic note is needed here. Gould (1947) considers all of the native
North American grass species previously assigned to Agropvron to be included in Elvmus. I have retained the name Agropvron here for the sake of clarity in comparisons between it and the work of Kemp and associates (1990). For leafhopper species which are reported to feed on species of
Elvmus, I have included Agropyron grasses as potential hosts.
Leafhoppers
When possible, all leafhopper specimens were identified to species. A few groups, however, are difficult to identify beyond genus because of similarities in adult features or unresolved taxonomic problems. Members of the genus Aceratagallia (subfamily Agalliinae) are nearly impossible to identify on the basis of females, and males are difficult as well. This genus is currently undergoing revision by K.G.A. Hamilton of the Canada Biosystematic Research
Institute. For the purposes of the present study, leafhoppers in this genus were studied at the generic level. A subsample of male specimens were identified as the species A. sanguinolenta and
A. uhleri. Both species are widely distributed across North America (Beirne, 1956; Delong,
1948).
11 The entire subfamily Typhlocybinae is also problematic, because of close similarities in external morphologic and genitalic features, especially in females. These leafhoppers are also very small (usually <3 mm in length), quite fragile and easily destroyed in sweep net samples. Within this subfamily, the genera Empoasca and Ervthroneura are difficult to identify and were covered only superficially by Delong (1948) and Beirne (1956). However, Oman (1949) gives excellent keys to genera for these groups. Despite the difficulty in identifying these leafhoppers, two taxa were identified to species. Most male Dikraneura specimens taken in this study were identified as
D. shoshone. a common grassland species. Given the occurrence of numerous female specimens in the samples (without accompanying males), these leafhoppers are analyzed as a genus. Another grassland species, Forcipata loca. is fairly distinctive and was identified to species. All other specimens of this subfamily were identified to genus in this study.
In the subfamily Deltocephalinae, females of the genera Athvsanella. Laevicephalus.
Limotettix (Scleroracus), and Sorhoanus are difficult (or impossible) to identify to species
(Beime, 1956; Blocker and Johnson, 1990; Delong, 1948; Ross and Hamilton, 1972). There are also some unresolved taxonomic problems in the genera Scleroracus and Sorhoanus (Hamilton
1992, pers. comm.).
In 1988, an attempt was made to identify specimens of these four genera to species
(Appendix A). The Athvsanella specimens from 1988 belonged to seven species, acuticauda. attenuata. occidentalis. robustus. sinuata. terebrans and utahna. In 1991, many females were encountered, often without associated males. Therefore, given the limitations in identifying females of this group, specimens were pooled as Athvsanella spp. All Laevicephalus specimens collected during this study were females in the “sylvestris-group” (Ross and Hamilton, 1972).
12 Given the general lack of characters for identifying females of this genus to species, specimens were analyzed as Laevicephalus spp. The Sorhoanus specimens from this study were primarily debilis. although flavidus and orientalis were taken in the mid-elevation mesic patches (Appendix
A). The Scleroracus specimens were largely females with few associated males. The male specimens of Scleroracus that were collected belong to the species dasidus and krvptus.
All leafhopper species identifications were made by myself and verified by K.G.A.
Hamilton of the Canadian Biosystematic Research Institute in Ottawa, Ontario, Canada (except for the genus Athvsanella. see above). Keys and figures given by Ball and Beamer (1940),
Beamer and Tuthill (1934, 1935), Beime (1952a, b; 1956), Blocker and Johnson (1990), Blocker and Wesley, 1985; Brown (1933), Crowder (1952), Delong (1926, 1935; 1948), Delong and
Davidson (1935); Delong and Sleesman (1929), Oman (1949), Ross and Hamilton (1972),
Whitcomb and Hicks (1988), and Young and Beirne (1957) were used to identify specimens sampled during this study. The taxonomy used in this paper follows these works and that of
Metcalf (1964).
Voucher specimens of all leafhopper taxa identified in this study have been deposited in the entomology collection at Montana State University, my personal collection or in the Canadian
National Collection at Ottawa, Ontario. A complete list of the leafhopper species (and their authors) identified during this study is contained in Appendix B.
13 Analysis
Correlation Analysis
To test the hypothesis that different plant assemblages have different leafhopper assemblages, I compared the relative abundance of leafhopper species between patches using
Spearman’s rank correlation analysis. Correlation analyses are useful in determining whether the distribution of two or more species are in some way related. A positive correlation between two species implies that when one increases in abundance, so does the other. A negative correlation implies that when one species increases in abundance, the other decreases. In community level analysis, with many species being compared between several sites, pairwise comparisons of variation in abundance can be performed to gather an overall measure of similarity (or dissimilarity) between the sample sites.
Spearman’s rank correlation coefficients were computed for comparisons between each of the 12 sample patches using MSUSTAT. Spearman’s rank correlation is a non-parametric test selected because it works well with non-normally distributed data (Ludwig and Reynolds, 1988).
Only correlation coefficients having a probability of <0.05 (given the sample size used) were considered significant. Correlation matrices were generated for each of the two sample years
(1988 and 1991) and for both years combined. Between patch comparisons did not include zero- zero matches in the data set (i.e. a leafhopper species had to be present on at least one of the two sample sites to be included in the analysis).
To test the hypothesis that the abundance of certain leafhopper species correlated with the percent cover of known or suspected food plants, I compared the total abundance (1988 and 1991 data combined) of each leafhopper species on each of the twelve sites with the percent cover of
14 both host and non-host plant species (using Spearman’s rank correlation analysis). Host plant preference was determined through a review of the literature, discussions with leafhopper experts, and personal observations.
Cluster Analysis
Cluster analyses are a multivariate procedure used to detect patterns (or groupings) in data. The relationship between data groups (samples) is usually represented in the form of a dendrogram. The length of the dendrogram branches and the width between them is representative of the degree of relatedness between the samples. Thus, the most similar groupings are closest to one another in the dendrogram. SYSTAT (Systat, Inc., 1992) was used to perform cluster analysis of the leafhopper data from each year and both years’ data combined.
The most crucial part of performing cluster analyses is the selection of the distance measure used to determine the degree of relatedness between samples. By selecting the wrong distance measure, spurious results can occur which cloud the interpretation of the analyses. Given that the leafhopper data were arranged in a rank order matrix, a distance measure was chosen that is designed for use with this type of data arrangement. SYSTAT (in its “CLUSTER” package) computes the Goodman-Kruskal gamma correlation coefficient for use with rank order data sets.
This distance measure was selected for use in generating dendrograms for the 1988, 1991 and combined data sets.
15 Descriptions of the Plant Assemblages and Patches
More than 65 taxa of plants were recorded during the 1991 sampling period (Kemp et al., unpub. data). O f these, 58 were selected for analysis (Table 2). Plant taxa were included in the analysis if they occurred in three or more of the 120 sampling plots in at least one of the four plant assemblages. The FEID/AGSP grasslands had the greatest plant diversity, with 38 species recorded. The Brin/Mesa grasslands were the least diverse, with 15 species recorded. Plant species names in the following descriptions are listed in order of abundance, from highest to lowest.
The Stipa comata/Bouteloua gracilis Association
The low elevation (1200-1400m) grasslands surveyed in this study occur on alluvial fans and plains within the Gallatin Valley and are dominated by Stipa comata and Bouteloua gracilis.
The grasslands sampled in this plant assemblage are semi-arid, with annual precipitation of 20-35 cm (Mueggler and Stewart, 1980). The patches also had a relatively low diversity of plant species
(29), when compared with the more mesic native grasslands occurring at higher elevations. Other important grasses and sedges in the STCO/BOGR type include Poa sandbergii. Koeleria cristata,
Carex filifolia. and Agropvron smithii. Total cover by grasses ranged from 50.2% to 62.4%, with an average of 54.5% (Table I).
The most common forb species observed in this plant assemblage include Sphaeralcea coccinea. Melilotus officinalis, various species of Antennaria and Astragalus. Vicia americana. and several species of Aster. Total cover by forbs ranged from 4.4% to 20.4%, with an average of
16 Table 2. Plant Species Frequency and Percent Cover at the Native Habitat Patches (1991 Data). NATIVE PLANT ASSEMBLAGES AND SAMPLING PATCHES PLANT Stipa comata/Bouteloua gracilis T ype Festuca idahoensis/A.eropyron spicatum T ype SPECIES 7A IOA 16A TOTAL 21A 2SA 26A TOTAL FRQ •/. CVR FRQ % CVR FRQ % CVR FRQ •/.CVR FRQ •/. CVF FRQ •/• CVR FRQ % CVR FRQ I tV CVR Stipa comata 97.50 32.55 100.00 36.00 100.00 26.90 99.17 31.82 30 00 4.05 20.00 1.43 15.00 0.80 21.67 2.09 Bouteloua gracilis 83.00 9.98 77.50 3.70 100.00 20.43 84.83 11.37 Poa sandbergii 67.50 1.85 77.50 2.00 62.50 2.08 « .1 7 1.98 Koeleria cristata 28.00 1.13 22.50 0.73 82.50 7.78 4433 3.21 42.50 1.45 37.50 1.68 26.67 1.04 Sphaeralcea coccinea 27.50 0.28 25.00 0.45 42.50 1.78 31.47 0.84 Carexfilifolia 10.00 0.40 45.00 7.53 30.00 4.90 2833 4.28 Kfelilotus officinalis 67.50 17.05 5.00 0.05 12.50 0.73 28-U 5.94 Agropyron smithii 60.00 3.95 15.00 0.15 25.00 137 37.50 3.05 5.00 0.38 14.17 1.14 Carex sp. I 5.00 0.05 10.00 0.10 30.00 0.30 15.00 0.15 Astragalus spp. 12.50 0.73 10.00 0.43 15.00 0.15 12.50 0.44 2.50 0.13 0.83 0.04 Vicia americana 17.50 1.30 17.50 0.18 11.47 0.49 Antennaria sp. I 32.50 4.58 10.83 1.53 Antennaria sp. 2 2.50 0.03 20.00 0.20 7.50 0.08 A ster spp 10.00 0.40 7.50 0.08 5.83 0.16 5.00 0.28 167 0.09 Taraxacum officinalis 15.00 0.15 5.00 0.05 5.00 0.05 1.67 0.02 Festuca octoflora 15.00 0.60 5.00 0.20 Agropyron spicatum 7.50 0.40 5.00 0.28 4.17 0.23 57.50 4.85 57.50 8.23 52.50 6.00 SSfO 6.36 Gutierrezia sarothrae 5.00 0.15 7.50 0.28 4.17 0.14 O puntia sp. 5.00 0.23 5.00 0.53 2.50 0.03 4.17 0.26 Phlox hoodii 5.00 0.05 7.50 0.18 4.17 0.08 10.00 0.30 3.33 0.10 Artemesia frigida 10.00 2.13 333 0.71 Guara coccinea 7.50 0.18 2.50 0.06 15.00 0.60 5.00 0.05 2.50 0.13 7.50 0.26 Liatris punctata 7.50 0.53 2.50 0.18 12.50 0.93 32.50 2.85 2.50 0.03 15.83 L27 Plantago patagonica 2.50 0.03 5.00 0.05 2.50 0.03 Bromus japonicus 5.00 0.05 1.67 0.02 17.50 0.28 5.83 0.09 Allysum desertorum 2.50 0.03 0.83 0.01 62.50 1.53 50.00 0.85 30.00 0.65 47.50 1.01 Gnaphalium viscosum 2.50 0.13 0.83 0.04 12.50 1.18 10.00 1.03 7.50 0.74 Tragopogon dubius 2.50 0.03 0.83 0.01 10.00 0.10 15.00 0.55 10.00 0.45 11.67 0 J7 Festuca idahoensis 77.50 12.18 92.50 21.90 100.00 23.03 90.00 19.04 Lycopodium sp. 30.00 7.53 60.00 12.28 60.00 11.03 50.00 10.28 Phlox longifolia 35.00 1.83 57.50 2.68 42.50 1.73 45.00 2.08 Cerastium arvense 30.00 2.05 30.00 3.38 65.00 6.25 41.67 3.89 Lupinus sericeus 20.00 2.43 50.00 6.13 52.50 11.18 40.83 6.58 Achillea millefolium 30.00 1.00 32.50 298 35.00 0.98 32.50 1.65 Kficrosteris gracilis 40.00 0.70 22.50 0.78 20.00 0.30 27.50 0.59 Balsamorhiza sagittata 22.50 8.25 10.00 3 50 47.50 19.00 26.67 10.25 Bromus tectorum 32.50 0.55 27 50 1.25 10.00 0.10 23.33 0.63 H ackelia spp. 25.00 0.36 40.00 0.80 5.00 0.28 23.33 0.48 Stipa viridula 37.50 2.30 27.50 1.53 21.67 1.28 A renaria serpiphylla 7.50 0.08 17.50 0.40 35.00 0.45 20.00 0.31 Collom ia sp. 30.00 0.30 22.50 0.23 5.00 0.05 19.17 0.19 Danthonia unispicata 32.50 1.38 20.00 2.40 17.50 1.26 Poa bulbosa 22.50 2.45 25.00 0 88 15.83 1.11 Commandra umbellata 32.50 1.80 7.50 0.08 2.50 0.13 14.17 0.67 Poa pratense 15.00 0.45 2.50 0.03 22.50 0.88 13.33 0.45 Polygonum sp. 25.00 0.25 2.50 0.03 9.17 0.09 Heterotheca villosa 2.50 0.03 5.00 0.53 7.50 0 18 5.00 0.25 Arenaria capillaris 7.50 0.75 5.00 0.50 4.17 0.42 R osa sp. 10.00 2.15 2.50 0.25 4.17 0.80 Senecio canus 10.00 2.63 3 J3 0.88 D elphinium sp. 2.50 0.03 5.00 0.05 2.50 0.03 Agropyron cristatum Draba sp. Kfedicago sativa Descurainia pinnata Bromus inermis Agropyron intermedium Phleum pratense 17 Table 2 cont'd. Plant Species Frequency and Percent Cover at the Replanted Patches (1991 Data).
REPLANTED PLANT ASSEMBLAGES AND SAMPLING PATCHES
PLANT Agropyron cristatum/M edicago sativa T y p e Brom us inermis/M edicago sativa T y p e SPECIES 7b 16b 1 7 b TOTAL 21b 25b 26b TOTAL FRQ % CVR FRQ % CVR FRQ % CVR FRQ % CVR FRQ •/. CVR FRQ •/• CVR FRQ % CVR FRQ V.CVR Stipa comata 2.50 0.03 12.50 0.65 5.00 0.38 6.67 0J5 Bouteloua gracilis 2.50 0.38 12.50 0.78 5.00 O Jf Poa sandbergii 15.00 0.25 5.00 0.08 2.50 0.13 0.83 0.04 Koeleha chstata 10.00 0.53 3,33 0.18 Sphaeralcea coccinea 12.50 0.33 27.50 0.68 7.50 0.30 15.83 0.44 Carexfilifolia Mfelilotus officinalis 100.00 37.25 33 J3 12.42 Agropyron smithii Carex sp. I Astragalus spp. 20.00 0.30 6.67 0.10 Vicia amehcana 2.50 0.38 57.50 4.13 10.00 0.50 23J3 1.67 A n tennaha sp. I A n tennaha sp. 2 A ster spp. Taraxacum officinalis 15.00 0.45 5.00 0.15 7.50 0.18 2J0 0.06 Festuca octoflora 25.00 0.55 8J3 0.18 Agropyron spicatum Gutierrezia sarothrae O puntia sp. Phlox hoodii Ahemesia fhgida Guara coccinea Liatris punctata Plantago patagonica 5.00 0.05 1,67 0.02 Bromus japonicus Allysum desertorum 0.50 0.05 5.00 0.15 5.00 0.05 3.50 0.08 52.50 0.73 15.00 0.15 22.50 0.29 Gnaphalium viscosum Tragopogon dubius 2.50 0.25 0,83 0.08 Festuca idahoensis Lycopodium sp. Phlox longifolia Cerastium arvense Lupinus sericeus Achillea millefolium 7.50 0.18 5.00 0.50 4.17 0.23 Microstehs gracilis 2.50 0.03 0.83 0.01 5.00 0.05 30.00 0.40 2.50 0.03 12 JO 0.16 Balsamorhiza sagittata Brom us tectorum H ackelia spp. 2.50 0.03 2.50 0.03 1.67 0.02 Stipa vihdula Arenaria serpiphylla 5.00 0.05 1,67 0.02 Collomia sp. 2.500.037.50 0.08 2.50 0.03 4.17 0.05 Danthonia unispicata Poa bulbosa 5.00 0.05 67.50 1.85 24.17 0.63 Commandra umbellata Poa pratense 12.50 2.68 25.00 2.15 100.00 40.98 45.83 15.27 Polygonum sp. Heterotheca villosa A renaria capillaris R osa sp. Senecio canus D elphinium sp. Agropyron cristatum 100.00 31.13 100.00 49.13 100.00 29.25 100.00 36.50 Draba sp. 22.50 0.33 7.50 0.11 Medicago sativa 7.50 0.18 2.50 0.06 92.50 17.55 52.50 5.25 48.33 7.60 Descurainia pinnata 2.50 0.03 0.83 0.01 Brom us inermis 100.00 20.80 100.00 57.25 97.50 26.83 99.17 J4.96 Agropyron intermedium 37.50 6.43 62.50 11.25 33.33 5.89 Phleum pratense 7.50 0.30 5.00 0.05 4.17 0.12
18 11.1% (Table I). Cover by bare ground ranged from 10.8% to 23.9%, with an average of 16.2%
(Table I).
The three patches sampled within this plant assemblage varied with respect to plant species composition, vegetative cover and plant species relative abundance (Table 2). Patch 7A is small (ca. 100 hectares) and relatively mesic (in the Agropyron smithii phase of the STCO/BOGR grassland type). Surrounded by heavily grazed native and replanted grasslands and agricultural fields. In addition to the defining grasses of this assemblage, Agropvron smithii and Melilotus officinalis are also common. Ofthe three patches sampled in this plant assemblage, Patch 7 A had the greatest number of plant species (22) and the greatest cover by forbs. Forb cover was predominantly Melilotus officinalis. Percent bare ground at 7A was the highest of the three patches; 7A is grazed by horses and wild ungulates.
Patch IOA is located 5 kilometers south of patch 7 A and represents an area of moderate plant species richness (16 species recorded). It is part of a large native grassland complex covering approximately 1,000 hectares north of the town of Logan, separated from 7 A by a series of high limestone ridges. Most of my observations on leafhopper-foodplant assemblages were made in this grassland complex (including Patch 9A). In protected areas upslope from the
STCO/BOGR plant assemblage, grasslands in the Agropvron spicatum /Agropyron smithii series occurred with greater representation by forbs and small shrubs such as Artemesia frigida and
Gutierrezia sarothrae. The area from which vegetation and insect samples were taken is rather dry and low in plant species diversity, when compared to other patches in this STCO/BOGR complex. Forb cover and bare ground values were the lowest of the three STCO/BOGR patches sampled. Patch IOA is lightly grazed by a small herd of horses and various wild ungulates.
19 Patch 16A is located 25 kilometers south of the town of Three Forks and is part of a livestock grazed native and replanted grassland complex spreading south along the Madison
River. It is the most intensively grazed of the three patches in this plant assemblage. Two to three hundred head of cattle may be present and the vegetation is often cropped low. Plant species richness was moderate (19 total) and grass cover totaled 62.4%, the highest value of the three patches. Cover by forbs and bare ground was also moderate (8.4% and 13.8%, respectively). Canopy cover of Bouteloua gracilis and Antennaria spp. (plants not readily grazed by cattle (Mueggler and Stewart, 1980) was significantly higher in patch 16A, compared with patches 7A and IOA. There was a corresponding decrease in coverage by Agropvron smithii and
Stipa comata, species favored by cattle. This condition usually indicates overgrazing (Mueggler and Stewart, 1980). An unusual finding is the high frequency and cover values for Koeleria cristata, a species usually favored by cattle. It is unknown why this grass did so well at 16A, despite the heavy grazing pressure. Mueggler and Stewart (1980) reported similar findings for this grass species elsewhere in southwest Montana.
The Festuca idahoensis/Agropyrou smcatum Association
As the valley floor rises north and east into the foothills (1400-23 00m) of the Bridger
Mountains, there is a corresponding increase in annual precipitation (average 35 to 50 cm). The grasslands sampled in this region had the greatest plant species richness, of the four types sampled, with 39 species recorded from the three patches. The sample patches were dominated by Festuca idahoensis and Agropvron spicatum. Other important grasses in this community type include Koeleria cristata. Bromus tectorum, Stipa comata. S. viridula. Danthonia unispicata. Poa
20 bulbosa, ARropyron smithii. and Poa pratensis. Total cover by grasses ranged from 31.33% to
35.48%, with an average of 33.99% (Table I).
The most common forbs recorded from this grassland type include species of
Lycopodium. Phlox longifolia. Cerastium arvense. Lupinus sericeus, Achillea millefolium.
Microsteris eracilis. Balsamorhiza sagitatta. species ofHackelia. Arenaria serpiphvlla. a species of
Collomia. Liatris punctata. Commandra umbellata. and a species of Polygonum. Total cover by forbs ranged from 30.61% to 49.42%, with an average of 36,89%(Table I). Cover by bare ground ranged from 2.70% to 10.63%, with an average of 6.70%(Table I).
The three patches in this plant community occur relatively close to one another on the west slope of the Bridger Mountains, northwest of Bozeman. All are roughly 100 hectares in size and surrounded by a complex of replanted and native grasslands. Upslope from these grasslands was a band of pine and spruce forest interspersed with mesic, forb- and grass- dominated meadows. Downslope was primarily agricultural land, planted to wheat, oats, and alfalfa. Cattle grazing also occurred (at varying intensities) on the sample patches. Plant species composition and percent cover values varied widely between the patches, but species dominance remained relatively consistent.
Patch 21A had the greatest number of plant species (32 species), but the lowest cover value for grasses (31.3%). There was also a high frequency of weedy species such as Allvsum desertorum. Cerastium arvense. Bromus tectorum. Poa bulbosa. and Poa pratensis. The regular occurrence of these species in native plant communities usually indicates a past history of disturbance (Swink and Wilhelm, 1994). Bare ground covered 6.8% of the area sampled.
21 Patch 25A had the lowest plant diversity (29 species), but the greatest cover value for grasses (35.5%) in the FEID/AGSP association. Danthonia unispicata was a significant member of the flora at both this and patch 26A. There was also a moderate frequency of the above- mentioned weedy species, but the lowest frequency of Pda pratensis. Clubmosses (Lycopodium spp.) were also a significant component of the flora. This site had the lowest percentage of bare ground (2.7%).
Patch 26A had a high plant species richness (31 species) and a high cover value for grasses
(35.2%). This patch was moderately grazed and had a high frequency of weedy species such as
Achillea millefolium. Bromus iaponicus. Cerastium arvense. and Poa pratensis. It is adjacent to a very high quality, lightly grazed FEID/AGSP grassland appearing to have a greater abundance of native plant species (Bess, pers. obs.). Bare ground accounted for 10.6% of the area sampled and was the highest value for the three patches in this type.
The Agropyron cristatum/Medicago sativa Association
These replanted grasslands were very low in plant species richness, with 16 species recorded. Cover by grasses was also low, with a corresponding increase in cover by bare ground.
The most abundant grass species on all three patches was Agropvron cristatum. Portions of the three sampling areas had not been completely stripped of the original vegetation, or had experienced recolonization by native grasses. These grasses appeared in the sample plots as scattered individuals of Festuca octoflora. Stipa comata. Bouteloua gracilis, and Poa sandbergii.
Total grass cover ranged from 30.4% to 51,0%, with an average of 40.5% (Table I). Cover by native grass species was less than 1.0% (mean) for this plant assemblage. Forbs included Vicia
22 americana. Sphaeralcea coccinea. species of Draba and Astragalus. Total cover by forbs ranged from 0.9% to 6.3%, with an average of 2.9% (Table I). Cover by bare ground ranged from
25.14% to 35.25%, with an average of 31.47% (Table I).
Patch 7B had the lowest number of plant species (7) and was dominated by Agropvron cristatum. with scattered weedy forbs such as Astragalus spp. and Sphaeralcea coccinea.
Melilotus officinalis was also a minor component. This patch also had the lowest cover by bare ground (25.1%) of the three patches sampled in this plant assemblage. Grass cover was moderate
(40.0%) and consisted solely of Agropvron cristatum.
Patch 16B had a relatively dense cover of Agropyron cristatum (49.1%), with scattered individuals o f a few native grasses, such as Bouteloua gracilis. Festuca octoflora. Poa sandbergii. and Stipa comata. Grasses covered 51.0% of the area sampled, the highest value among the three patches. Forbs were dominated by the disturbance-tolerant species Sphaeralcea coccinea and
Vicia americana. Bare ground covered 35.3% of the area sampled, the highest value of any of the patches sampled.
Patch 17B was relatively depauperate in plant species, vegetative cover consisting of scattered Agropvron cristatum. Bouteloua gracilis. Stipa comata. Vicia americana and
Sphaeralcea coccinea. Cover by grasses was the lowest of any patch sampled (30.4%); cover by forbs was also very low (0.9%). Bare ground comprised 34.0% of the area sampled, second highest value for this plant assemblage.
23 The Bromus inermis/Medicago sativa Association
This was the least species rich of the four grassland types sampled, with 15 plant species recorded in 1991. The most commonly recorded grasses were Bromus inermis. Poa pratensis.
Agropvron intermedium. Poa bulbosa. and Phleum pratense. All but Poa bulbosa are considered non-native and are assumed to have been brought in by humans (intentionally or unintentionally).
Poa bulbosa is reported as being widely distributed in disturbed areas and mesic meadows throughout Montana (Dorn, 1984). Total grass cover ranged from 23.8% to 79.2%, with an average of 57.0% (Table I).
The most commonly recorded forbs were Medicago sativa. Alvssum desertorum. and
Microseris gracilis. Other incidental forbs include; Achillea millefolium. Collomia spp.,
Taraxacum officinalis. Arenaria serpiphvlla. and Tragopogon dubius. Most of these forb species are non-native and weedy in nature. Total forb cover ranged from 1.09% to 18.36%, with an average of 8.49 (Table I). Bare ground ranged from 0.70% to 11.73%, with an average of 6.06%
(Table I).
The three patches sampled in this plant assemblage varied greatly with respect to plant species dominance and percent cover. Patch 2IB had the lowest plant species richness (8), lowest grass cover value (23.53%), and greatest cover by alfalfa (17.55%). Bare ground covered
11.73% of the area sampled, highest value for this plant assemblage. This patch was vegetated entirely with disturbance tolerant species such as Allysum desertorum. Bromus inermis. Medicago sativa. and Poa pratensis. The sample plots contained no Agropyron intermedium or Phleum pratense. both of which are present on patches 25B and 26B.
24 Patch 25B also had a low number of plant species (11 species), but a high cover value for grasses (67.98%). This patch had no alfalfa present in the sampling plots. A total of five species of grasses were present and Agropvron intermedium. Poa bulbosa. and Poa pratensis were co dominants with Bromus inermis. I assume that A. intermedium and P. pratense were planted along with B. inermis. All other plants were recorded in low numbers and represent disturbance- tolerant taxa such as Allvssum desertorum, Hackelia spp. and Microseris gracilis.
Patch 26B had the highest cover value for grasses (79.24%) with Poa pratensis. Bromus inermis and Agropyron intermedium dominating (in that order). Alfalfa was present, consisting of widely scattered individuals. Other plants were minor components of the flora and consisted of weedy, disturbance tolerant species.
25 RESULTS
Leafhopper Species Collected
Overall, a total of 44,429 leafhoppers, representing at least 67 taxa in ten subfamilies, were recorded in the 1988 and 1991 samples from the twelve patches (Appendix A). These were reduced to 58 taxa (see Materials and Methods) for use in analysis (Tables 3-7). Of these 58 taxa,
46 were shared between the native and replanted grasslands, 12 were found, only in the native types and 7 were recorded only in the replanted habitats (Tables 5 and 6). In the 1988 samples, a total of 17,098 leafhopper specimens were recorded from the twelve patches (Table 3), while
27,331 specimens were recorded in 1991 (Table 4). In 1991, only 377 (14%) of the 27, 331 specimens were collected in the additional September sample (Appendix A). The following sections present the leafhopper abundance data for the four plant assemblages, by each year and both years combined. Leafhopper genera and species names are listed in descending order of abundance.
The Stipa comata/Bouteloua gracilis Association
The 1988 Data
A total of 4,347 leafhoppers were recorded from this plant assemblage in 1988 (Table 3).
The most commonly recorded leafhopper species were Orocastus perpusillus. members of the genera Athysanella, Aceratagallia and Sorhoanus. Mocuellus caprillus. Orocastus labeculus.
Rosenus cruciatus, Auridius helvus. Cuema striata. Stenometopiellus cookei. and Deltocephalus
26 Table 3. 1988 Leafhopper Species Abundance Data from the Twelve Patches.
GRASSLAND PLANT ASSEMBLAGES AND PATCHES'
LEAFHOPPER STCO/BOGR FEID / AGSP Agcr / Mesa Brin / M esa SPECIES 7A IOA 16A Total 21A 25A 26A Total 7b 16b 17b Total 21b 25b 26b T otal Orocastus perpusillus 438 1788 120 2346 i4 10 2 27 7 3 10 Aceratagallia spp. 240 33 97 370 79 15 177 271 1413 18 27 1458 1568 8 177 1753 , j ■ Mocuellus caphllus 160 53 3 216 I 4 15 20 2 2 I Hebecephalus crueiatus 98 18 40 156 45 18 63 15 3 2 2 0 Auridius he Ivus 63 9 72 31 31 3 3 Sorhoanus spp. 53 121 60 234 231 159 225 615 8 31 i 40 34 30 185 249 Orocastus labeculus 49 129 21 199 7 9 9 25 4 8 i 13 39 39 Cuenta striata 48 10 58 3 3 40 I 41 5 I 6 Athysanella spp. 45 57 305 407 30 17 18 65 13 12 19 44 29 29 Deltocephalus valens 33 11 2 46 11 3 22 36 7 7 Hebecephalus rostratus 11 15 12 38 18 I I 20 4 2 9 15 3 I 4 Colladonus montanus 8 8 Dikraneura spp. 7 20 27 23 24 2 49 91 35 11 137 98 73 171 Dorycephalus platyrhynchus 6 16 I 23 9 9 Prairiana cinerea 4 3 3 10 I I 2 Endria rotunda 3 3 Flexamia abbreviata 3 3 Hecalus spp. 2 I 3 9 6 102510 22 6597 3 20 23 Psammotettix lividellus 2 4 10 16 35 79 9 123 41 114 360 515 95 81 190 366 Colladonus geminatus i 6 7 I 131410 5 152 8 9 19 Flexamia Jlexulosa i 2 29 32 Frigartus frigidus I 2 3 I I Xerophloea viridis I I 12 2 2 16 2 2 Stenometopielus cookei 48 48 I I Commellus sexvitattus 15 15 3 I 4 I : I Pinumius areatus 2 2 Empoasca sp. I I 3 3 6 2 2 4 Streptanus conjinis II Prairiana subta 2 2 Chlorotettix unicolor 114 66 7 187 I I 2 5 7 Endria inimica 39 9 21 69 I I 107 58 1544 1709 Doratura stylata 20 23 15 58 7 517 2153 2677 Macrosteles quadrilineatus 15 13 28 43 5 7 55 Diplocolenus conjtguratus i I 2 4 II 50 176 77 303 Mesamia coloradensis I i I I Neoeolidia tumidifrons 5 5 i I Limotettix spp. 11 11 I I Ballana veruta 2 2 Laevicephalus sp. 2 2 3 3 Norvelina seminuda 2 2 Elymana sp. (F) I I II 2 2 Texananus spp I II I Idiodonus aurantiaeus 2 2 Lonatura sp. (F) I 16 I 18 Dikrella sp. 2 2 Amblysellus grex II 72 9 591 672 Balclutha punctata 2 2 123 5 128 Nesosteles neglectus II Latalus missellus 6 22 102 130 Athysanus argentarius 33 7 40 Elymana circius 72 72 Auridius auratus 33 33 Forcipata Ioca 3 3 Scaphytopius spp. 2 2 INDIVIDUAL TOTAL 1277 2365 70S 4347 713 479 602 1794 1674 271 506 2451 2119 1055 5332 8506 SPECIES TOTAL 23 24 14 29 22 22 26 33 21 15 16 28 15 18 27 32 ' Plant Assemblages: STCO/BOGR = Stipa comata/Bouteloua gracilis type; FEID/AGSP = Festuca idahoensis/ Agropyron spicatum type; Agcr/Mesa =Agropyron cristatum/Medicago sativa type; Brin/Mesa = Bromus inermis/ Kdedicago sativa ty p e . Table 4. 1991 Leafhopper Species Abundance Data from the Twelve Patches.
GRASSLAND PLANT ASSEMBLAGES AND PATCHES1 LEAFHOPPER STCO/BOGR FEID Z AGSP Agcr/Mesa Brin / Mesa SPECIES 7A IOA 16A Tetal 21A 25A 26A Telal 7b 16b 17b Total 21b 25b 26b Total
Aceratagallia spp. 923 190 411 1524 135 121 76 332 898 186 36 1120 649 129 185 963 Mocuellus caprillus 242 31 2 275 17 76 93 6 6 Athysanella spp. 197 69 746 1012 70 28 98 129 305 114 548 2 i 25 28 Orocastus labeculus 112 329 149 590 26 76 62 164 2 54 2 58 II Sorhoanus spp. 90 83 16 189 499 487 323 1309 26 14 3 43 35 36 132 203 Psammotettix lividellus 18 9 27 54 35 20 18 73 23 56 67 146 24 96 212 332 Orocastus perpusillus 16 484 16 516 95 16 i 112 6 I 7 Chlorotettix unicolor 8 8 74 34 15 123 6 6 4 4 Dikraneura spp. 6 4 I 11 76 70 6 152 20 a 7 38 105 197 124 426 Macrosteles quadrilineatus 6 8 12 26 65 61 2 128 5 9 3 17 69 60 18 147 Empoasca sp. 5 I 6 I 4 5 10 2 22 24 Flexamia flexulosa 5 4 59 68 Auridius ordinatus 4 5 2 11 47 2 49 7 45 52 Colladonus geminatus 4 4 18 12 16 46 2 2 85 9 13 107 Hebecephalus rostratus 4 6 7 17 7 II 9 III 3 HecaIus spp. 4 3 7 2 2 5 9 11 7 38 56 3 26 29 C uem a striata 3 I 5 9 6 6 12 IIII Stenometopielus cookei 3 28 I 32 I I Commellus sexvitattus I 4 4 I I 13 13 Dorycephalus platyrhynchus I 4 5 Auridius he Ivus 3 3 I I Rosenus erueiatus 3 3 I I Flexamia abbreviata 2 2 Frigartus frigidus i I I I Deltocephalus valens I I Limotettix spp. I I i 8 9 8 8 Nesosteles neglectus I I 3 3 I W W m Endria inimica 14 29 43 20 1704 4109 5833 Doratura stylata 12 i 24 37 5 5 26 2655 6262 8943 Auridius auratus 7 7 Mesamia coloradensis 3 I 3 7 I I Laevicephalus sp. (F) i i I I Scaphytopius spp. I i 2 6 6 Xerophloea viridis 6 6 12 Diplocolenus configuratus 2 5 7 24 285 122 431 Balclutha punctata I I 2 2 I 10 11 Forcipata Ioca I I Neocolidia tumidifrons II Elymana circius 18 18 6 45 51 Latalus missellus I I 26 86 112 Paraphlepsius occidentalis I I Hardya dentata 3 I 4 Amblysellus grex i 4 19 165 188 Athysanus argentarius 28 67 95
INDIVIDUAL TOTAL 1652 1267 1458 4377 1213 953 710 2876 1139 654 273 2066 1045 5282 11684 18011
SPECIES TOTAL 2 0 2 0 18 27 24 22 26 35 17 13 i i 2 0 13 21 2 2 2 7
1 Plant Assemblages: STCO/BOGR = Stipa comata/Bouteloua gracilis type; FEID/AGSP = Festuca idahoensis/Agropyron spicatum type; Agcr/Mesa = Agropyron cristatum/Medicago saliva type; Brin/M esa = Bromus inermis/Medicago saliva ty p e .
28 Table 5. Leafhopper Abundance by Plant Assemblage (1988/1991 Combined Data),
GRASSLAND PLANT ASSEMBLAGES1 LEAFHOPPER STCO/BOGR FEID Z AGSP Agcr/Mesa Biin / Mesa TOTAL SPECIES % o f N n •/. o fN n % of N n % of N Sum (n) % of N Orocastus perpusillus 2862 33% 139 3% 17 0% 3018 7% Aceratagallia spp. 1894 22% 603 13% 2578 57% 2716 10% 7791 18% Athysanella spp. 1419 16% 163 4% 592 13% 57 0% 2231 5% Orocastus labeculus 789 9% 189 4% 71 2% 40 0% 1089 2% Mocuellus caprillus 491 6% 113 2% 8 0% I 0% 613 i% Sorhoanus spp. 423 5% 1924 42% 83 2% 452 2% 2882 7% Rosenus cruciatus 159 2% 63 1% 21 0% 243 1% Flexamia Jlexulosa 100 1% 100 0% Stenometopielus cookei 80 1% 2 0% 82 0% Auridius he Ivus 75 1% 32 1% 3 0% HO 0% Psammotettix lividellus 70 1% 196 4% 661 15% 698 3% 1625 4% Cuema striata 67 1% 15 0% 42 1% 7 0% 131 0% Hebecephalus rostratus 55 1% 29 1% 18 0% 4 0% 106 0% Deltoeephalus valens 47 1% 36 1% 7 0% 90 0% Dikraneura spp. 38 0% 201 4% 175 4% 597 2% 1011 2% Dorycephalus platyrhynchus 28 0% 9 0% 37 0% Macrosteles quadrilineatus 26 0% 156 3% 17 0% 202 1% 401 1% Commellus sexvitattus 16 0% 8 0% I 0% 14 0% 39 0% Colladonus geminatus 11 0% 60 1% 17 0% 126 0% 214 0% Auridius ordinatus 11 0% 49 1% 52 0% 112 0% Hecalus spp. 10 0% 34 i% 153 3% 52 0% 249 1% Prairiana cinerea 10 0% 2 0% 12 0% Chlorotettix unicolor 8 0% 310 7% 7 0% 11 0% 336 1% Colladonus montanus 8 0% 8 0% Empoasca sp. 7 0% 16 0% 28 0% SI 0% Flexamia abbreviate 5 0% 5 0% Frigartusfrigidus 4 0% 2 0% 6 0% Endria rotunda 3 0% 3 0% Pinumius areatus 2 0% 2 0% Prairiana subta 2 0% 2 0% Xerophloea viridis I 0% 28 i% 2 0% 31 0% Limotettix spp. I 0% 20 0% 9 0% 30 0% Nesosteles neglectus I 0% 3 0% 1 0% I 0% 6 0% Streptanus confinis I 0% I 0% Endria inimica 112 2% I 0% 7542 28% 7655 17% Doratura stylata 95 2% 5 0% 11620 44% 11720 26% Elymana eireius 18 0% 123 0% 141 0% Diplocolenus conjiguratus 11 0% I 0% 734 3% 746 2% Mesamia coloradensis 8 0% 2 0% 10 0% Auridius auratus 7 0% 33 0% 40 0% Neocolidia tumidifrons 6 0% I 0% 7 0% Laevicephalus sp. (F) 3 0% 4 0% 7 0% Ballana veruta 2 0% 2 0% Norvelina seminuda 2 0% 2 0% Scaphytopius spp. 2 0% 8 0% 10 0% Texananus spp. I 0% I 0% 2 0% Latalus missellus I 0% 242 1% 243 1% Forcipata Ioca I 0% 3 0% 4 0% Paraphlepsius occidentalis I 0% I 0% Balclutha punctata i 0% 4 0% 139 1% 144 0% Lonatura sp. (F) 18 0% 18 0% Hardya dentata 4 0% 4 0% Amblysellus grex 2 0% 860 3% 862 2% Dikrella sp. 2 0% 2 0% Idiodonus aurantiaeus 2 0% 2 0% Elymana sp. (F) I 0% I 0% 2 0% 4 0% Athysanus argentarius 135 1% 135 0% Cicadula quinquinotata i 0% i 0% TOTAL # INDIVIDUALS (N) 8724 4670 4517 26518 44429
1 Plant Assemblages: STCO/BOGR = Stipa comata/Bouteloua gracilis type; FEID/AGSP = Festuca idahoensis/Agropyron spicatum ty p e ; Agcr/Mesa = Agropyron cristatum/Medicago saliva type; Brin/Mesa = Bromus inermis/Medicago saliva ty p e .
29 Table 6. Leafhopper Abundance Data for the Twelve Patches (1988/1991 Combined),
GRASSLAND PLANT ASSEMBLAGES AND PATCHES' LEAFHOPPER STCO/BOGR FEID / AGSP A g c r / Mesa B r i n / Mesa SPECIES 7 A IO A 1 6 A 21A 2SA 26A 7B 16B I7B 21B 25B 2 6 B Aceratagallia spp. W i i 223 508 214 135 253 2311 204 63 2217 137 362 Orocastus perpusillus 454 2272 136 n o 26 3 13 I 3 Mocuellus caprillus 402 84 5 18 4 91 6 2 I Athysanella spp. 242 126 1051 100 45 18 142 317 133 2 3 52 Orocastus labeculus 161 458 170 33 85 71 6 62 3 I 39 Sorhoanus spp. 143 204 76 730 646 548 34 45 4 69 66 317 Rosenus cruciatus 98 21 40 45 18 16 3 2 Auridius he Ivus 63 12 32 3 C uem a striata 51 11 5 9 6 41 I 5 II Deltocephalus valens 33 11 3 11 3 22 7 Psammotettix lividellus 20 13 37 70 99 27 64 170 427 119 177 402 Hebecephalus rostratus 15 21 19 25 2 2 5 3 10 3 I Dikraneura spp. 13 24 I 99 94 8 111 46 18 105 295 197 Colladonus montanus 8 Chlorotettix unicolor 8 188 100 22 7 6 5 Dorycephalus platyrhynchus 7 20 I 9 Hecalus spp. 6 4 11 8 15 21 29 T 03 " 6 46 Flexamia Jlexulosa 6 6 88 Macrosteles quadrilineatus 6 8 12 80 74 2 5 9 3 112 65 25 Colladonus geminatus 5 6 19 12 29 12 5 87 17 22 Empoasca sp. 5 I i 4 7 5 2 2 24 Prairiana einerea 4 3 3 II Auridius ordinatus 4 5 2 47 2 7 45 Endria rotunda 3 Flexamia abbreviata 3 2 Stenometopielus cookei 3 76 I II Frigartus frigidus I 3 2 Xerophloea viridis I 12 8 8 2 Commellus sexvitattus I 15 7 II 13 I Pinumius areatus 2 Streptanus confinis I Prairiana subta 2 Limotettix spp. II 19 9 Nesosteles neglectus I 3 I I Endria inimica 53 9 50 I 127 1762 5653 Doratura stylata 32 24 39 5 33 3172 8415 Auridius auratus 7 33 Mesamia coloradensis 4 I 3 I I Diplocolenus conjiguratus I 3 7 i 74 461 199 Laevicephalus sp. (F) I 2 I 3 Scaphytopius spp. I I 8 Neocolidia tumidifrons 6 i Balelutha punctata I 2 2 123 I 15 Forcipata Ioca I 3 Elymana circius 18 6 117 Ballana veruta 2 Norvelina seminuda 2 Texananus spp. I I Latalus missellus I 6 48 188 Paraphlepsius occidentalis I Idiodonus aurantiaeus 2 Lonatura sp. (F) I 16 i Elymana sp. (F) II 2 Hardya dentata 3 I Dikrella sp. 2 Amblysellus grex I I 76 28 756 Athysanus argentarius 61 74 Cicadula quinquinotata I
T O T A L # I N D I V I D U A L S 2 9 2 9 3 6 3 2 2163 1926 1431 1312 2813 925 779 3164 6 3 4 0 1 7 0 1 4
T O T A L # S P E C I E S 29 27 23 28 27 34 25 2 0 1 9 19 2 6 3 0
1 Plant Assemblages: STCO/BOGR = Stipa comata/Bouteloua gracilis type; FEID/AGSP = Festuca idahoensis/Agropyron spicatum ty p e ; A g c r/M e s a =Agropyron cristatum/Medicago sativa type; Brin/M esa = Bromus inermis/Medicago saliva ty p e .
30 Table 7. Leafhopper Species Richness by Subfamily and Plant Assemblage.
LEAFHOPPER PLANT ASSEMBLAGE1 SUBFAMILY STCO/BOGRFEID/AGSP Agcr/Mesa Brin/Mesa AGALLIINAE I I I I TETTIGONIELLINAE I II I
GYPONINAE 2 I I I HECALINAE I I II DORYDIINAE II O O DELTOCEPHALINAE 30 35 26 27 NEOCOELIDIINAE O II O
BALCLUTfflNAE I 2 2 2
TYPHLOCYBINAE 2 3 2 3
LEDRINAE I . 1 O . I TOTALS 40 47 35 37
1Plant Assemblages: STCO/BOGR = Stipa comata/Bouteloua gracilis ; FEID/AGSP = Festuca idahoensis/Agropyron spicatum; A g c r /M e s a =Agropyron cristatum/Medicago saliva ; Brin/M esa =Bromus inermis/Medicago saliva.
31 valens. The remaining leafhopper taxa identified from the 1988 samples each represented less than 1.00% of the total recorded for this plant assemblage (Table 3). The 1991 Data
A total of 4,377 leafhoppers representing 28 taxa were recorded from this plant assemblage in 1991 (Table 4). The most commonly recorded leafhoppers were species of
Aceratagallia and Athvsanella. Orocastus labeculus. Orocastus perpusillus. Mocuellus caprillus. the genus Sorhoanus. Flexamia flexulosa. and Psamotettix lividellus. All other leafhopper taxa each represent less than 1.00% of the total number recorded for this plant assemblage (Table 4).
The Combined Data
The low elevation native grasslands of Gallatin County, Montana were relatively low in leafhopper species richness (40 taxa total). The most abundant leafhopper taxa recorded from this plant assemblage were Orocastus perpusillus. several members of the genera Acerataeallia and Athvsanella. Orocastus labeculus. Mocuellus caprillus. three species in the genus Sorhoanus.
Rosenus cruciatus. Flexamia flexulosa. and Stenometopiellus cookei (Tables 3-6; Figure I).
Several leafhopper species were recorded almost exclusively from the STCO/BOGR plant assemblage, although they appeared in low numbers (Tables 3-6; Figure I). These include
Colladonus montanus (8 specimens from patch 7A, 1988 only), Dorvcephalus platyrhynchus
(found primarily in the low elevation native grasslands, (28 specimens), but also in the mid elevation ones (nine specimens)), Endria rotunda (three specimens from patch 7A, 1988 only),
Flexamia abbreviatta (five specimens from the STCO/BOGR grasslands and a Bouteloua specialist), Pinumius areatus (two specimens, patch 16A), Prairiana cinerea (ten specimens from the STCO/BOGR grasslands, two from the Agcr/Mesa patches), and P. subta (three specimens
32 Figure I. Leafhopper Species Abundance - STCO / BOGR Grasslands (1988-1991 Combined)
10000
I!I Ila !III I l I I j i i i i i I f I j iiIii
Species Name from patch 16A). Each of these seven species represented less than one percent of the total number of leafhoppers recorded from this plant assemblage.
The Festuca idahoensis/Agropyron spicatum Association
The 1988 Data
A total of 1,794 leafhoppers representing 29 taxa were recorded from this plant assemblage in 1988 (Table 3). The most common leafhoppers were members of the genera
Sorhoanus and Aceratagallia. Chlorotettix unicolor. Psamotettix lividellus, Endria inimica. several species of Athvsanella, Rosenus cruciatus. Doratura stylata. Dikraneura shoshone. Deltocephalus valens. Auridius helvus. Macrosteles quadrinotata. Orocastus labeculus. Mocuellus caprillus and
Hebecephalus rostratus. All other leafhopper taxa identified in the 1988 samples each represented less than 1.00% of the total number recorded for this plant assemblage (Table 3).
The 1991 Data
A total of 2,876 leafhoppers representing 36 taxa were recorded from this plant assemblage in 1991 (Table 4). Those most commonly recorded were species of Sorhoanus and
Aceratagallia. Orocastus labecullus, Dikraneura shoshone. Macrosteles quadrinotata. Chlorotettix unicolor. Orocastus perpusillus. the genus Athvsanella. Mocuellus caprillus. Psamotettix lividellus. the genus Auridius, Colladonus geminatus. Endria inimica. and Doratura stylata. All other leafhopper taxa each represent less than L 00% of the total recorded from this plant assemblage
(Table 4).
34 The Combined Data
The mid-elevation native grasslands had the greatest leafhopper species richness (47 taxa total) of the four types sampled (Tables 5 and 6). Samples were dominated by members of the genera Sorhoanus and Aceratagallia. Chlorotettix unicolor, several species of Athvsanella.
Dikraneura shoshone. Orocastus labeculus. Psammotettix lividellus, Doratura stylata, Endria inimica, Macrosteles quadrinotata and Mocuellus caprillus (Tables 3-6; Figure 2).
Several additional leafhopper species were recorded primarily from this plant assemblage, although in low numbers (Tables 5 and 6; Figure 2). These include Xerophloea viridis (28 specimens in the FEID/AGSP grasslands, compared with only one from the STCO/BOGR patches and two from the Brin/Mesa patches), members of the genus Limotettix (subgenus Scleroracus
(20 specimens from the FEID/AGSP patches, nine from Brin/Mesa and one from the
STCO/BOGR association)), Mesamia coloradensis (eight specimens from the FEID/AGSP patches, two from the Brin/Mesa association), and Neocolidia tumidifrons (six specimens from the
FEID/AGSP patches, one from the Agcr/Mesa).
The Agropyron cristatum/Medicago sativa Association
The 1988 Data
A total of 2,451 leafhoppers representing 28 taxa were recorded from this plant assemblage in 1988 (Table 3). Samples contained a few wide-ranging taxa such as members of the genus Aceratagallia, Psamotettix lividellus. Dikraneura shoshone. species of Hecalus, a few
Athvsanella. Cuerna striata, and the genus Sorhoanus. All other leafhopper taxa each represented less than 1.00% of the total number recorded from this plant assemblage (Table 3).
35 Figure 2. Leafhopper Species Abundance - FEID / AGSP Grasslands (1988-1991 Combined) 10000
I I s I I H iM I =: § ; M | H H i I i ^ s I 11
Species Name The 1991 Data
A total of 2,066 leafhoppers representing 19 taxa were recorded from this plant assemblage in 1991 (Table 4). Those most commonly recorded were species of AceratagalUa and
Athvsanella. Psamotettix lividellus. Orocastus labeculus. Species of Hecalus, the genus Sorhoanus and Dikraneura shoshone. All other leafhopper taxa each represent less than 1.00% of the total recorded from this plant assemblage (Table 4).
The Combined Data
These grasslands had the lowest leafhopper Species richness (35 species total) of the four plant assemblages sampled (Table 5). Samples were dominated by common, widespread taxa such as the genus Aceratagallia. Psammotettix lividellus. a few species of Athvsanella. Dikraneura shoshone. species of Hecalus and the genus Sorhoanus (2.00%). Other leafhoppers recorded consistently, but in low numbers, include Colladonus geminatus. Cuerna striata. Hebecephalus rostratus. Lonatura sp., Macrosteles quadrinotata, Orocastus labeculus. and Rosenus cruciatus
(Tables 3-6, Figure 3). A few leafhopper species were recorded exclusively or predominantly from this plant assemblage (Tables 3-6). These include an unidentified species of Lonatura (18 female specimens, only at the Brin/Mesa patches), Hardva dentata (four specimens recorded only in this plant assemblage), and a species of Dikrella (two specimens, patch 16b). ‘
The Bromus inermis/Medicago sativa Association
The 1988 Data
A total of 8,506 leafhoppers representing 32 taxa were recorded from this plant assemblage in 1988 (Table 3). Samples were dominated by Doratura stylata. species of
3 7 Figure 3. Leafhopper Species Abundance - Agcr / Mesa Grasslands (1988-1991 Combined)
10000
I ; ; i I ; I ; i Iisii
Species Name Aceratagallia. Endria inimica. Amblvsellus grex. the genus Athvsanella. Psamotettix lividellus.
Diplocolenus configuratus. the genus Sorhoanus. Dikraneura shoshone. Latalus missellus. and
Balclutha punctata. All other leafhopper taxa each represent less than 1.00% of the total number recorded from this plant assemblage (Table 3).
The 1991 Data
A total of 18,011 leafhoppers representing 26 taxa were recorded from this plant assemblage in 1991 (Table 4). Those most commonly recorded were Doratura stylata, Endria inimica. the genus Aceratagallia. Diplocolenus configuratus. Dikraneura shoshone. Psamotettix lividellus and the genus Sorhoanus. All other leafhopper taxa each represent less than 1.00% of the total recorded from this plant assemblage (Table 4).
The Combined Data
These mid-elevation replanted grassland patches were relatively low in leafhopper species richness (37 species total). Samples were dominated by large numbers of a few widespread taxa, such as Doratura stylata. Endria inimica. species of Aceratagallia. Amblvsellus grex, Diplocolenus configuratus. Psammotettix lividellus. Dikraneura shoshone. and members of the genus
Sorhoanus. The Brin/Mesa patches had the largest leafhopper samples recorded (Tables 3-6,
Figure 4).
39 Figure 4. Leafhopper Species Abundance - Brin / Mesa Grasslands (1988-1991 Combined)
100000
10000 - -
e v i I I I i IMII 3 I ! I 13 Il I Il
Species Name Several species were recorded primarily from this plant assemblage (Tables 3-6). These include Athysanus argentarius (135 from the Brin/Mesa type only), Auridius auratus (33 specimens from the Brin/Mesa, seven in the FEID/AGSP type), Balclutha punctata (139 from the
Brin/Mesa, four from the Agcr/Mesa and one from the FEID/AGSP types), Elvmana circius (123 from the Brin/Mesa type, 19 in the FEID/AGSP patches), and Latalus misselhis (242 from the
Brin/Mesa patches, one from the FEID/AGSP patches).
41 RESULTS: A COMPARISON OF LEAFHOPPER ASSEMBLAGES IN DIFFERENT PATCHES
The Spearman’s correlation analyses allow comparison in the overall similarity between leafhopper assemblages in different patches for each year and for data combined across years. For each data set, three types of comparisons will be made: I) between patches characterized by the same plant assemblage, 2) between patches characterized by different native plant assemblages
(i.e. STCO/BOGR vs. FEID/AGSP), and 3) between patches characterized by native plant assemblages and replanted ones within the same habitat region (i.e. STCO/BOGR vs. Agcr/Mesa and FEID/AGSP vs. Brin/Mesa). Other potential comparisons (i.e. the STCO/BOGR vs.
Brin/Mesa, FEID vs. Agcr/Mesa, and Agcr/Mesa vs. Brin/Mesa) were deemed less relevant ecologically and are not discussed further in this study. Results of the cluster analysis are also included in each of the following three sections.
The 1988 Data
Ofthe 39 potential comparisons between the 12 patches, 15 resulted in significant between-site correlations in the relative abundance of leafhopper species (Table 8). Eight of the significant correlations occurred between sites characterized by the same plant assemblage. The leafhopper assemblages at all three STCO/BOGR patches were significantly correlated with one another, suggesting that similarities in the local plant assemblage results in similar resident leafhopper communities.
42 Table 8. Spearman’s Correlations in Leafhopper Species Abundance Between the Twelve Patches (1988 data).1
PLANT ASSEMBLAGES 2 SIr C O /B O G R FEID/AGSP Agcr/Mesa Irin/Mesa Patch 7A IOA 16A 21A 25A 26A 7B 16B 17B 21B 25B 26B 7A 0.60 *** 0.50 * 0.38 NS 0.49 * 0.36 NS 0.34 NS 0.08 NS 0.32 NS -0.46 0.51 ** -0.35 * 28 24 23 2 2 23 23 23 2 2 31 33 41 * * * IOA 0.49 * 0.49 0.49 * 0.41 0.42 0 .1 1 NS 0.25 NS -0.47 ** -0.45 ♦ * -0.30 NS 24 24 25 24 25 28 27 32 34 40 * 16A 0.65 0.54 * 0.38 NS 0 .2 2 NS 0 .0 2 NS 0 .2 0 NS -0.41 * -0.54 ** -0.27 NS 14 14 14 25 2 2 2 0 25 28 35 21A 0.73 *** 0.28 NS 0.29 NS 0.30 NS 0 .2 0 NS -0 .0 2 NS 0.07 NS 0.15 NS 25 30 28 27 27 26 27 33 25A 0 .2 1 NS 0.28 NS 0 .2 2 NS 0.19 NS -0.17 NS 0.08 NS 0.18 NS 32 28 27 26 26 28 35 26A 0.16 NS 0.03 NS' -0.04 NS -0 .1 0 NS -0 .0 2 NS 0 .1 0 NS 30 32 32 32 32 36 * * 7B 0.50 0.49 -0 .2 1 NS -0:15 NS 0 .0 1 NS 25 24 28 27 37 16B 0.41 NS -0.31 NS -0 .1 1 NS 0 .1 1 NS 21 23 25 33 17B -0.25 NS -0.31 NS -0.14 NS 25 27 34 21B 0.24 NS 0.45 * 2 1 30 25B 0.64 *** 31 26B
’Significance levels: * = P<0.05; ** = PO.Ol; *** = P O .001; NS = not significant. The number in the lower left hand comer of each block is the number of leafliopper species compared between patches minus one. 2Plant Assemblages: STCO/BOGR = Stipa comata/Bouteloua gracilis; FEID /A G SP = Festuca idahoensis/Agropyron spicatum; A gcr/M esa = Agropyron cristatum/Medicago sativa; B rin/M esa = Bromus inermis/Medicago sativa. The remaining cases of close similarity in leafhopper communities were primarily between the two native plant assemblages (STCO/BOGR and FEID/AGSP), where 6 of 9 correlations were significant. In contrast, there was very little similarity between leafhopper assemblages at the native STCO/BOGR patches and nearby sites replanted to AgcrZMesa (one of nine). This analysis indicates that degree of similarity in plant species composition is more important than spatial proximity in determining the leafhopper fauna of grassland patches in Gallatin County.
In comparisons among leafhopper assemblages from the FEID/AGSP patches, 21A and
25A were significantly correlated, while 26A did not correlate closely with either patch. None of the nine comparisons between the FEID/AGSP and Brin/Mesa patches were significant, again suggesting that replanting with non-native plant species greatly alters the composition of the resident leafhopper fauna. Leafhopper samples from patches within each of the non-native plant assemblages showed some similarity with each other (2 of 3 comparisons significant within both the Agcr/Mesa and Brin/Mesa types), although most of these significant correlations were relatively weak.
The cluster analysis performed on the 1988 leafhopper data resulted in an arrangement of the 12 patches (Figure 5) different from that obtained with the correlation analyses. One striking result was the clustering of several STCO/BOGR patches with ones from the Brin/Mesa assemblage (i.e. 7A and IOA with 21b; 16A with 26b). In fact, patches 7A (STCO/BOGR) and
21b (Brin/Mesa) were the sites most closely associated in the dendrogram. The correlation analysis showed 7A and 21b to have a significant, but negative (rs = -0.46, P O .01) relationship.
44 Figure 5. Cluster Analysis of the 1988 Leafhopper Data from the Twelve Patches1
Distance Measure is I minus Goodman-Kruskal's gamma coefficient Single Linkage Method (Nearest Neighbor).
Plant Assemblage1 Patch DISTANCES 1.000
FEIDZAGSP 26 A.
STCOZB OGR IOA
STCOZBOGR 7A
BrinZMesa 21b
FEIDZAGSP 21A
FEIDZAGSP 25A
AgcrZMesa 16b
BrinZMesa 25b
BrinZMesa 26b
STCOZB OGR 16A-
AgcrZMesa 7b
AgcrZMesa 17b
'Plant Assemblages: STcOZBOGR=Szzpa comata/Bouteloua gracilis; FElDZAGSP=FesZMca idahoensis/Agropyron spicatum ; AgcrZMesa = Agropyron cnstatumfMedicago sativa; BrinZMesa = Bromus inermis/Medicago sativa.
45 The correlation between IOA and 21b was also negative and significant (rs = -0.47, P<0.01). In contrast, patches 21A and 25A were also closely associated in the dendrogram, a condition that is supported by the raw data and correlation analysis. Patch 7b also associated closely with patch
17b, and the two formed an outlier group relative to the rest of the patches. Site 16b, however, clustered quite closely with most of the patches, an association unconfirmed by either the correlation analysis or the raw data.
The 1991 Data
Ofthe 39 potential comparisons between patches, 13 were significant (Table 9). Ten of these significant correlations occurred between patches characterized by the same plant assemblage. As in 1988, the leafhopper assemblages at all three STCO/BOGR patches were significantly correlated with one another, but showed very little similarity to the nearby non-native
Agcr/Mesa patches (i.e. only I of 9 comparisons were significant). Other similarities with the
1988 data include: I) leafhopper assemblages at 26A being uncorrelated with those from 21A or
25 A and 2) leafhopper assemblages at the FEE)/AGSP patches being uncorrelated with those from the Brin/Mesa patches. Leafhopper samples from patches within each of the two non-native plant assemblages were more closely correlated in 1991 than 1988 (i.e. all comparisons significant in both Agcr/Mesa and Brin/Mesa). Perhaps the greatest difference between the 1988 and 1991 leafhopper samples was the reduction in similarity between the two native plant associations (i.e. only 2 of 9 correlations were significant, compared with 6 of 9 in 1988).
f
46 Table 9. Spearman’s Correlations in Leafhopper Species Abundance Between the Twelve Patches (1991 data).1
PLANT ASSEMBLAGES 2 STCO/BOGR FlEID/AGSP Agcr/Mesa Brin/Mesa Patch 7A IOA 16A 21A 25A 26A 7B 16B 17B 21B 25B 26B 7A 0.65 *** 0.65 *** 0.64 *** 0.58 ** 0.23 NS 0.72 *** 0.45 * 0.40 NS 0.03 NS -0,21 N -0.18 N 24 23 28 27 32 2 1 23 2 2 26 28 31 IOA 0 . 6 8 *** 0.39 * 0.28 NS -0.06 NS 0.48 * 0.40 NS 0.30 NS 0.21 NS -0.28 N -0.27 N 24 32 30 33 23 23 2 2 27 32 33 16A 0.35 N 0.35 NS -0.04 N 0.35 NS 0.40 NS 0.31 NS -0.13 NS -0.30 NS -0.26 NS 28 28 32 23 2 2 2 1 24 30 30 21A 0.57 *** 0.27 NS 0.65 *** 0.47 * 0.35 NS 0.39 * 0.16 NS 0.02 NS 31 32 27 25 25 26 30 31 25A 0.28 N 0.60 ** 0.52 * 0.45 * 0.30 NS 0.04 NS -0.06 NS 31 30 23 24 26 28 29 26A 0.22 NS 0.10 NS 0.01 NS 0.28 NS 0.26 NS 0.19 NS 30 29 29 29 32 31 7B 0.57 ** 0.62 ** 0.18 NS -0.09 NS -0.09 NS 2 0 19 23 27 30 16B 0.80 *** 0.20 NS 0.00 NS 0.12 NS 14 19 24 26 17B 0.09 NS -0.05 NS 0.15 NS 17 23 25 21B 0.60 ** 0.50 * 23 24 25B 0 7 9 *** 25 26B
'Significance levels: * = P O .05; ** = P O .01; *** = PO.OOl; NS = not significant. The number in the lower left hand comer of each block is the number of leafhopper species compared between patches minus one. 2Plant Assemblages: STCO/BOGR = Stipa comata/Bouteloua gracilis; FEID/AGSP = Festuca idahoensis/Agropyron spicatum ; Agcr/Mesa = Agropyron crisiatum/Meaicago sativa ; Brin/Mesa = Bromus inermis/Medicago sativa. As observed in 1988, cluster analysis of the 1991 leafhopper data resulted in some very unusual associations between the twelve patches, although they were more closely related than in
1988 (Figure 6). Patch 7A was most closely associated with 16b, and this cluster (7A and 16b) with 16A. Patch 7A was only weakly associated with 16b in the correlation analysis, being most closely related to IOA both years (Tables 8 and 9). In the cluster analysis, IOA was not closely associated with 7 A, being one of the least dissimilar of the twelve patches compared. As in 1988,
Goodman-KruskaV s gamma coefficient analysis may not be approbate for this data set.
The Combined Data for 1988 and 1991
Ofthe 39 potential comparisons using the combined leafhopper data from the twelve patches, 22 were significant (Table 10). All twelve of the potential comparisons between patches characterized by the same plant assemblage were significant at P < 0.01 or P < 0.001. Thus, combining data from two years with different precipitation patterns resulted in an even greater indication that patches with similar plant species composition tend to have similar leafhopper assemblages.
Combining results for the two years did not alter the conclusions that leafhopper assemblages differ between the FEDD/AGSP and Brin/Mesa patches. However, whereas in 1988 and 1991 there was little indication of significant correlation in the leafhopper assemblages of the
STCO/BOGR and Agcr/Mesa patches, significant correlations appeared in 6 of 9 comparisons using the combined data. Thus, differences observed between the leafhopper assemblages at the
STCO/BOGR and Agcr/Mesa patches become
48 Table 10. Spearman’s Correlations in Leafhopper Species Abundance between the Twelve Patches. (1988/1991 combined data).1
PLANT ASSEMBLAGE 2 STCO/BOGR F]EID/AGSP Agcr/Mesa Brin/Mesa Patch 7A 10A 16A 21A 25A 26A 7B 16B 17B 21B 25B 26B 7A 0.72 *** 0.64 *** 0.42 ** 0.48 ** 0.30 * 0 . 6 6 *** 0.19 NS 0.45 ** -0.19 NS -0.24 NS -0.21 NS 31 32 38 36 43 34 36 34 37 40 44 IOA 0.62 *** 0.42 ** 0.34 * 0.17 NS 0.55 *** 0.26 NS 0.42 ** -0.21 NS -0.23 NS -0.23 NS 30 37 36 43 33 34 32 36 39 43 16A 0.32 NS 0.31 NS 0.05 NS 0.38 * 0.17 NS 0.40 * -0.28 NS -0.31 NS -0.21 NS 34 32 42 32 31 27 31 37 40 21A 0.74 *** 0.43 ** 0.52 ** 0.45 ** 0.38 * 0.1 Ns 0.25 NS 0.15 NS 33 38 35 35 34 32 36 36 25A 0.49 ** 0.57 *** 0.43 * 0.43 * 0.21 NS 0.21 NS 0.17 NS 40 38 32 30 31 34 37 26A 0.38 * 0.12 NS 0.12 NS 0.15 NS 0.21 NS 0.24 NS 38 42 40 37 39 40 7B 0.41 ** 0.57 *** 0.04 NS 0.01 NS 0.04 NS 31 29 33 35 40 16B 0.63 *** 0.11 NS 0.07 NS 0.16 NS 24 28 33 38 17B 0.06 NS 0.10 NS 0.02 NS 27 33 37 21B 0.52 *** 0.48 ** 29 33 25B 0.76 *** 33 ‘Significance levels: * = P<0.05; ** = P<0.01; *** = P O .OO I; NS = not significant. The number in the lower left hand comer of each block is the number of leafhopper species compared between patches minus one. 2Plant Assemblages: STCO/BOGR = Stipa comata/Bouteloua gracilis; F E ID /A G S P = Festuca idahoensis/Agropyron spicatum ; A g c r/M e sa =Agropyron cristatum/Medicago sativa ; Brin/M esa = Bromus inermis/Medicago sativa. Figure 6. Cluster Analysis of the 1991 Leafhopper Data from the Twelve Patches1
Distance Measure is !minus Goodman-Kruskal s gamma coefficient Single Linkage Method (Nearest Neighbor).
P la n t A ssem b lag e1 P a tc h DISTANCES 0.500
AgcrZMesa 17b
STCOZBOGR 16A
AgcrZMesa 16b
STCOZBOGR 7A-
AgcrZMesa Tb
BrinZMesa 26b-
BrinZMesa 25b
FEIDZAGSP 25A -
FEIDZAGSP 26 A-
FEIDZAGSP 21A
STCOZBOGR IOA-
BrinZMesa 21b- lPlant Assemblages: STCOZBOGR=Stipa comata/Bouteloua gracilis; FElDZAGSP=Fejfuca idahoensis/Agropyron spicatum; AgcifMes^=Agropyron cnstatum/Medicago saliva; BrinZMesa=BroniMJ inermis/Medicago saliva.
50 less evident when compared over a longer time interval. The leafhopper fauna’s of the
STCO/BOGR and FEDD/AGSP patches remained somewhat closely correlated, with four of nine
comparisons significant.
In contrast to the dendrograms produced with the individual sampling year’s data, the cluster analysis of the combined data resulted in associations that more closely matched the correlation analyses and patterns observed in the raw data (Figure 7; Tables 6 and 10). The combined data dendrogram showed patches 7A and IOA to be most closely associated, followed by 16A (all within the STCO/BOGR plant assemblage). The cluster containing these sites was then most closely associated with a cluster containing two of the native mid-elevation patches,
21A and 25 A. These five patches formed a fairly discrete, native grassland cluster.
The next discrete cluster in the dendrogram is composed of patches 7b, 16b and 17b in the
Agcr/Mesa assemblage. Patch 21b is an outlier associated with the above-mentioned clusters.
The final cluster in the dendrogram (containing patches 26A, 26b and 25b) is very interesting and reflects patterns observed in the correlation analysis and the raw data. These three sites contained many rare and unusual leafhopper taxa, resulting (at least in part) from the high diversity of observed plant species. Although these sites were closely associated with one another in the dendrogram, they form a distinct outlier group distantly related to patch 21b and the remaining sample sites.
51 Figure 7. Cluster Analysis of the Combined Leafhopper Data from the Twelve Patches1
Distance Measure is l-Goodman-Kruskal's gamma coefficient. Single Linkage Method (Nearest Neighbor).
Plant Assemblage1 Patch DISTANCES 1.000 Brin/Mesa 21b
AgcrZMesa 17b
AgcrZMesa 16b
AgcrZMesa Tb
FEIDZAGSP 25A-
FEIDZAGSP 21A-
STCOZBOGR 16A-
STCOZB OGR TA-
STCOZBOGR IOA-
FEIDZAGSP 26 A-
BrinZMesa 26b-
BrinZMesa 25b- lPIant Assemblages: STCOfBOGR-Stipa comata/Bouteloua gracilis; FEIDZAGSP=FesfMca idahoensis/Agropyron spicatum; AgCTfMssa=Agropyron cnstatum/Xledicago saliva; BrinZMesa=SromMs inemiis/Medicago saliva.
52 DISCUSSION
Similarity in Leafhopper Assemblages between Sites
Overall, the correlation analyses support the hypothesis that leafhopper assemblages occurring on grassland patches in Gallatin County tend to be most similar among sites characterized by the same plant assemblage. The leafhopper assemblages occurring on native grasslands were also found to be mostly uncorrelated with those on nearby replanted grasslands, although samples from several of the STCO/BOGR and Agcr/Mesa patches did correlate significantly using the combined 1988/1991 data. In addition, many significant correlations occurred when comparing the leafhopper assemblages from the STCO/BOGR and FEID/AGSP patches.
The cluster analysis produced many unusual and spurious associations when used on the individual year’s leafhopper data. However, when the combined data were analyzed, groupings very similar to those determined by plant assemblage were observed. The STCO/BOGR grasslands were the most closely associated, followed by two of the FEID/AGSP patches. The
Agcr/Mesa patches were also found to be closely associated, although patches 26A, 25b and 26b formed a distinctive outlier, closely associated with one another but not the remaining patches.
This pattern mimics that shown in the plant data, with the native patches being most similar to onne another (see Table 2). Patches 26A, 25b and 26b also had unusual vegetative components
(i.e. all three having high cover values for Poa pratensef when compared to the remaining sites in their plant assemblage.
53 Correlation between Leafhopper Species Abundance and Percent Cover of Know Host Plants
Host plant associations are unknown for many species of Cicadellidae. However, several of the species collected in this study are known well enough to allow testing of the hypothesis that their abundance across the twelve patches correlates with percent cover of known or suspected host plants (Table 11). The following is a discussion of the thirteen leafhopper taxa used in this comparison and how their abundance correlated with percent cover of known or suspected hosts.
Aceratasallia spp.
Aceratagallia spp. (primarily A. sanguinolenta and A. uhleri) were relatively abundant across all patches (Table 6). Their overall abundance correlated highly with percent cover by plants in the family Fabaceae (Table 11), their known host plants (Beirne, 1956; Delong, 1948).
Aceratagallia sanguinolenta. for example, is a common transcontinental species known as the clover or alfalfa leafhopper (Beirne, 1956; Delong, 1948). Of the twelve patches sampled,
Aceratagallia leafhoppers were most abundant at sites 7 A, 16A and 7b, all of which had high cover values for yellow sweet clover IMelilotus officinalis! and site 21b which had abundant alfalfa IMedicago sativa). Given the prevalence of these plant species in disturbed habitats throughout the county, they perhaps serve as the major local hosts for these leafhoppers.
In addition to occurring in disturbed Fabaceae-dominated sites, Aceratagallia leafhoppers were observed in a variety of native plant associations where the only potential hosts were native
Fabaceae. These potential host plants were primarily species of Astragalus (in low elevation
Stipa/Bouteloua grasslands and in alpine tundra) and Lupinus (in the Festuca idahoensis/Agropvron spicatum grasslands and other montane meadow communities). Members
54 Table 11. Correlation between Leafhopper Species Abundance and Percent Cover for Eleven Plant Taxa (1991 data)1.
Plant Taxa2 A. spicatum, Leafhopper Taxa Agropyron spp. Agropyron A. spicatum, A. smithii, Bouteloua Poa spp. Stipa Fabaceae cristatum A. smithii A. intermedium eracilis comata Acertagallia spp. NS NS NS NS NS NS NS 0.66* Amblysellus grex NS NS -0.75** NS NS NS -0.87*** NS Athysanus argentarius NS NS NS NS NS 0.69* -0.58* NS Chlorotettix unicolor NS NS 0.68* 0.65* NS NS NS NS Diplocolenus configuratus NS NS NS NS -0.85*** 0.89*** -0.71** NS Doratura stylata NS NS NS 0.59* -0.75** 0.92*** -0.61* NS Dorycephalus platyrhynchus NS NS 0.62* NS NS NS 0.77** NS Endria inimica NS NS NS NS -0.85*** 0.96*** -0.67* NS Flexamia Jlexulosa -0.58* NS NS NS 0.85*** NS 0.74** NS Hecalus major 0.88*** 0.89** NS NS NS NS NS NS Latalus missellus NS NS NS NS NS 0.82*** -0.72** NS Orocastus labeculus NS NS -0.83* NS 0.67* -0.62* 0.94** NS Orocastus perpusillus NS . NS 0.64* NS 0.61* -0.58* 0.95** NS 1 Significance levels: * = P O .05; ** = P O .01; *** = PO.OOl. 2 Correlations in BOLD are known or suspected food plants for these leafhopper species. of these plant genera are common throughout southwestern Montana and likely serve as major hosts for these leafhoppers in more pristine, native plant assemblages. Over twice as many
Aceratagallia leafhoppers were collected in the replanted patches (Table 6).
Amblvsellus grex
Beime (1956) reported A. grex as being widely distributed in southern British Columbia.
The host plant of this leafhopper is unknown and its abundance did not correlate positively with percent cover values for any of the dominant grass species occurring in the four plant assemblages
(Table 11). The closely related A. curtisii is reported to feed on bluegrass (i.e. Poa spp.) in the
Midwest (Delong, 1948).
Athvsanus argentarius
Athysanus argentarius is a non-native leafhopper species introduced to eastern Canada from
Europe in 1940 (Beime, 1956). From eastern Canada, A. argentarius has spread westward to
Manitoba and Montana, and southward to Iowa and Kentucky (Beirne, 1956; Bess, pers. obs.;
Hamilton, 1983). Athysanus argentarius is reported to feed on a variety of grasses and its abundance at the twelve patches correlated strongly with percent cover by Poa spp. (Table 11).
Chlorotettix unicolor
The genus Chlorotettix is associated primarily with grasslands and wetlands in the Great
Plains and Midwest (Blocker and Reed, 1976; Cwikla, 1987; Delong, 1948). Known host plants are grasses in the genera Andropogon. Calamagrostis. Schizachvrium and Sorghastmm
(Hamilton, pers. comm.; Panzer et al.., 1995). The widespread Chlorotettix unicolor is transcontinental (Beime, 1956; Delong, 1948) and is associated with a variety of habitats, from wet to dry, pristine native to highly degraded (Bess, pers. obs.; Delong, 1948; Panzer, pers.
56 comm.). In 1991 and 1992,1 swept numerous specimens of C. Unicolor from isolated patches of
Agropyron smithii and A. spicatum on the STCO/BOGR grasslands surrounding Logan,
Montana. Both nymphs and adults were collected from these grasses, further confirming their use as hosts by this leafhopper. From an analysis of the 1988 and 1991 data, C. unicolor was found to be most common in the FEID/AGSP grasslands (Table 5), where its abundance correlated with percent cover by native Agropyron spp. (Table 11). This leafhopper was also swept in low numbers from the replanted grasslands, where it may be using introduced species of Agropyron as hosts.
Diplocolenus configuratus
Diplocolenus configuratus is native to Montana and was very abundant in the Brin/Mesa habitats (Table 5). This leafhopper also occurred in the FEID/AGSP patches and I collected several specimens of D. configuratus above treeline on Mount Blackmore and along the crest of the Bridger Mountains in 1991 and 1992. Delong (1948) reported this species as occurring in association with Canada bluegrass fPoa compressa), a non-native, European grass species found throughout the East and Midwest (Hitchcock, 1951). I have collected D. configuratus from Poa compressa and P. pratensis in a variety of habitats across the Midwest, including my lawn in northwest Indiana. The abundance of D. configuratus at the twelve patches correlated highly with percent cover by Poa spp. (Table 11).
57 Doratura stvlata
Doratura stvlata is a European leafhopper that has spread westward from its original introduction in the Great Lakes region (Hamilton, 1972). This species is extremely abundant in
Poa-dominated habitats such as pastures and lawns in the Midwest (Bess pers. obs.; Delong,
1948). Beime (1956) stated that D. stvlata probably feeds on grass roots in marshes and meadows. Abundance of this species at the twelve patches correlated strongly with percent cover by Poa spp. (Table 11). This leafhopper was most abundant in the Brin/Mesa association, although it occurred in lesser numbers in the FEID/AGSP association (Table 5).
Dorvcephalus platvrhvnchus
Dorvcephalus platvrhvnchus is reported to feed on wild rye IElymus spp.) and is known to use native and introduced species of Agropvron (Bess, pers. obs.; Hamilton, pers. comm.; Panzer et al, 1995). This leafhopper’s use of native Agropyron species was confirmed by significant correlations between its abundance and percent cover by Agropvron smithii and A. spicatum
(Table 11). Gould (1947) considers all of the native North American grass species previously assigned to Agropyron to be included in Elymus. meaning that D. platvrhvnchus is probably monophagous on Elymus.
Endria inimica
Endria inimica is a native, transcontinental leafhopper species occurring in a variety of habitats (Beime, 1956; Delong, 1948). It appears to prefer Poa pratensis as a host (see Beirne,
1956) and I have collected large numbers of both E. inimica and D. stvlata from Poa pratensis- dominated fields in the Midwest. The abundance of this leafhopper at the twelve patches correlated strongly with percent cover by Poa spp. (Table 11).
58 Flexamia abbreviatta and F. flexulosa
Flexamia abbreviata and F. flexulosa are known to feed exclusively on the grass genus
Bouteloua. preferring B. gracilis and B. hirsutus (Whitcomb and Hicks, 1988). Both Flexamia species were recorded only from the STCO/BOGR plant assemblage (Table 5). Abundance of
Flexamia flexulosa correlated strongly with percent cover of its only known host, Bouteloua gracilis. The abundance ofF. flexulosa also, correlated significantly with percent cover of Stipa comata, which occurs in the same habitat, but this grass is not considered a host. Hamilton (pers. comm.) stated that few leafhopper species appear to specialize on Stipa comata as a food plant.
Both species of Flexamia reach the northwestern limit of their respective ranges in western
Montana and Alberta (Whitcomb and Hicks, 1988).
Hecalus spp.
Hecalus leafhoppers occurred most abundantly in the Agcr/Mesa grasslands, especially at
17b (Table 4). Males were identified as belonging to both Hecalus major and H. viridis. but
Whitcomb and associates (1996) consider the taxonomy of this group to be in question, thus rendering specific identifications questionable. Both Hecalus major and H. viridis are considered moderately remnant dependent in Illinois (Panzer et a!, 1995), where H. major is associated with wet prairie containing its host, Calamagrostis canadensis (Delong, 1948; Panzer et al., 1995).
Hecalus viridis is considered a species of xeric prairie in Illinois, where it is reported to feed on
“native grasses” (Panzer et al, 1995).
Hecalus leafhoppers are certainly not remnant dependent in Gallatin County, Montana, where they were found to be fairly common in native and replanted patches. These leafhoppers were most abundant in the Agcr/Mesa assemblage. Abundance of Hecalus spp. showed positive
59 correlations with cover by Agropvron grasses (Table 11), their suspected host plants in Gallatin
County. Adults of these leafhoppers appeared in large numbers in the late spring (late May/early
June) samples, while the mid-summer (late July) samples were dominated by nearly full grown nymphs. This suggests that Hecalus leafhoppers produce a brood prior to when A. cristatum becomes semi-dormant in the heat of August, allowing them to successfully use this grass as a host.
Latalus missellus
Latalus missellus is reported to occur throughout the northern United States, Canada and
Alaska (Beirne, 1956; Delong, 1948). In my study, this leafhopper was found almost exclusively in the Brin/Mesa association (one specimen collected at patch 26 A in the FEED/AGSP association), where its abundance correlated strongly with percent cover by Poa spp. (Table 11).
I have also collected L. missellus from Poa compressa and P. pratense in Indiana.
Qrocastus labeculus and O. perpusilus
The two species of Orocastus are reported to feed on Stipa comata (Hamilton, pers. comm.) and their abundance correlated strongly with percent cover by this species (Table 11).
Both leafhoppers were most abundant at patch IOA (Table 6), which had the greatest percent cover by Stipa comata (Table 2). Orocastus perpusillus was most abundant in the spring samples
(May and June), when this cool season grass is in full bloom and at a maximum growth state.
Orocastus labeculus peaked in abundance roughly one month later when this grass species was setting seed. It has been hypothesized that leafhopper species abundance is closely tied to seasonal growth flushes in their host plants, especially during flowering and fruit set (Waloff,
1980; Whitcomb et al.„ 1987).
60 Conclusions Concerning LeafhopperZHost Plant Associations
The abundance of several leafhopper species collected from grassland patches in the
Gallatin Valley correlated closely with percent cover of known host plants, thus supporting the hypothesis (for some species) that the distribution of leafhoppers is correlated with the distribution of their host plants. Further observational and experimental studies to determine exact leafhopper-host plant associations would help interpret the distribution of additional leafhopper species among the four plant assemblages. Such studies would also help determine whether some of the weaker leafhopper/host plant correlations observed in this study were actually a result of host plant specificity or were a result of some other limiting factor(s) (e.g. if the leafhopper had similar abiotic requirements as the plant but did not actually feed on it).
Leafhopper Taxa occurring Primarily in the Native Plant Assemblages
Several leafhopper taxa were recorded exclusively (or primarily) in the native grassland patches. These include Chlorotettix unicolor. Deltocephalus valens. Mocuellus caprillus.
Orocastus perpusillus, Rosenus cruciatus. Stenometopielus cookei. and Xerophloea viridis.
Chlorotettix unicolor and Xerophloea viridis were most abundant in the FEID/AGSP assemblage while the remaining species were most abundant in the STCO/BOGR patches. Chlorotettix unicolor and Mocuellus caprillus are native Agropyron feeders in Gallatin County (Bess, pers. obs ), although C. unicolor is associated with Andropogon and Calamagrostis grasses in the
Midwest (Bess, pers. obs.). In 1991 and 1992,1 collected numerous individuals of M- caprillus from Agropvron smithii and A. spicatum on the grasslands surrounding Logan, Montana, in association with the leafhoppers Auridius helvus and Chlorotettix unicolor. Orocastus
61 perpusillus is a Stipa comata specialist throughout southern Canada and the northwestern United
States (Hamilton, pers. comm.). Xerophloea viridis is reported to feed on Aristida grasses in the
Midwest (Delong, 1948). The food plants of the remaining species are unknown for Gallatin
County.
Deltocephalus valens and Rosenus cruciatus were both most abundant in the 1988 samples from the STCO/BOGR patches, but were almost entirely absent from the 1991 samples. The food plants of these leafhoppers are unreported, but assumed to be grasses. I have swept R. cruciatus from Koeleria cristata in oak savanna’s of northwest Indiana, where this leafhopper is considered to be very rare (Panzer et al., 1995). Delong (1948) considered R. cruciatus to be a prairie species. Not much is known about Deltocephalus valens. but other Deltocephalus species in the Midwest are considered host specific and/or remnant dependent (Bess unpub. data; Delong,
1948; Panzer et al., 1995).
Stenometopiellus cookei appears to overwinter as an adult and is among the first leafhoppers to appear in the spring, usually in association with the leafhopper Hardya dentata and nymphs of various Athvsanella spp. (Bess, pers. obs.). I collected many individuals of both S. cookei and H. dentata in March and April, from grasslands dominated by Agropvron smithii. A. spicatum, Stipa comata; and S. viridula near the towns of Logan and Three Forks. These two leafhoppers belong to genera that are primarily Eurasian in distribution, with disjunct species (S. cookei. H. dentata and the closely related H. voungif in the western United States and Canada
(Hamilton, 1983).
62 Leafhopper Taxa occurring Primarily in the Replanted Plant Assemblages
An interesting phenomenon observed during this study was the occurrence of several leafhopper species almost exclusively in the replanted patches. This grouping includes
AmblysellUs grex. Athvsanus argentarius. Balclutha punctata. Diplocolenus configuratus.
Doratura stylata. Elvmana circius. Endria inimica. the genus Hecalus. Latalus missellus, and a species ofLonatura. All of these species, with the exception ofLonatura. were recorded almost exclusively from the Brin/Mesa patches. The Lonatura females were recorded from patch 16b in the Agcr/Mesa assemblage.
Athvsanus argentarius and Doratura stvlata are European leafhopper species introduced into the Midwest and having since spread westward to at least Montana. Both are considered general grass feeders, although their abundance at the twelve patches correlated significantly with percent cover by Poa spp. The leafhoppers Diplocolenus configuratus. Endria inimica. and
Latalus missellus are native species associated with northern meadow and pasture communities in southern Canada and the northern United States. All three are considered Poa feeders (Beime,
1956; Bess, pers. obs.; Delong, 1948) and their abundance across the twelve patches correlated significantly with percent cover by these grasses.
Balclutha puncatata is another widespread leafhopper species occurring in a variety of grasslands, pastures and agricultural situations throughout temperate regions of the world
(Beirne, 1956; Delong, 1948; Hamilton, 1983; WalofF,, 1973). Whitcomb et al. (1994) consider this leafhopper to be a general grass feeder in North America, preferring species in the tribe
Chloridoideae. This is an interesting observation, as no chloridoid grasses were found at patch
21 A, where this leafhopper was collected in very large numbers (Table 6). Poa pratensis and
63 Bromus inermis were the only grass species found in the sampling plots at 21b, occurring very frequently and providing relatively extensive cover (Table 2). Both grasses belong to the tribe
Poeae. Therefore, it appears that B. punctata may be utilizing these non-chloridoid grass species as hosts in southwest Montana.
Elvmana circius is a species new to the leafhopper fauna of the United States, being previously known from populations in the mountains of Alberta and British Columbia (Hamilton and Chiykowski, 1985). It is most likely that E. circius is feeding on Agropvron spp. (=Elymus, following Gould, 1947) in southwest Montana, as members of the genus Elvmana are reported to feed predominantly on grasses in the genus Elymus (Hamilton and Chiykowski, 1985; Delong,
1948). Hamilton and Chiykowski (1985) also report E, circius from Bromus and “other grasses”.
In the Brin/Mesa association, this leafhopper was recorded only from patches 25B and 26B. Both patches have (in addition to Bromus inermis) a high frequency and percent cover of Agropvron intermedium, a potential host plant. Several E. circius were also recorded at patch 26A in the
FEID/AGSP association, where they may be feeding on Agropvron spicatum.
Beime (1956) states that Lonatura leafhoppers are associated with grasslands and the host plants are probably grasses. The specimens collected from 16b are pale yellowish and unmarked, putting them close to L. crocea (Beirne, 1956). Delong (1948) associated L. catalina with the grass Aristida gracilis in Illinois. Stipa is closely related to Aristida and represents a potential host for the Lonatura species recorded at 16b, where S. comata was fairly frequent (Table 2).
64 Leafhopper Taxa with Wide Distributions in the Gallatin Valley (but no well-defined plant assemblage or host plant preferences)
Several of the more abundant leafhopper taxa displayed no obvious association with any one plant assemblage. These include members of the genus Auridius. Colladonus geminatus.
Cuema striata. Hebecephalus rostratus. Macrosteles quadrilineatus. and Psammotettix lividellus.
The Auridius leafhoppers appear to be using species of Agropvron as hosts (Bess, pers. obs.;
Hamilton, pers. comm ), although they were conspicuously rare in the samples from the
Agcr/Mesa patches. The BrinZMesa collections were nearly all (78 of 85) from patch 26b which had abundant cover of Agropvron intermedium, a replanted species native to Montana. It is possible that species of Auridius prefer native Agropvron as hosts.
Colladonus geminatus and Cuema striata are widely distributed throughout the United
States and southern Canada, where they are reported to feed on a variety of herbaceous plants, trees and shrubs (Beime, 1956; Delong, 1948). Colladonus geminatus was most abundant in the patches at the more mesic end of the valley, especially in the BrinZMesa assemblage. This leafhopper is reported to feed on a variety of trees and shrubs (Beime, 1956). Cuerna striata was most abundant at the more xeric end of the valley, being somewhat more common in the
STCO/BOGR assemblage. The genus Cuema is primarily boreal and montane in distribution
(Beime, 1956), with Cuerna striata occurring throughout Canada and the United States (Beime,
1956; Delong, 1948). Delong (1948) reports C. lateralis (= striata Walker) to be “abundant in pastures and herbaceous growth in cutover areas” in Illinois. Its food plants in Montana are unknown.
65 Psammotettix lividellus is a circumpolar species occurring across Canada and the northern
United States (Beirne, 1956; Hamilton, 1983). In this study, P. lividellus occurred across all patches, but was most abundant in the replanted grasslands. In 1991 and 1992,1 collected this species in a variety of native and non-native plant assemblages throughout Gallatin County.
Given its broad distribution, it is probable that P. lividellus is a general feeder on a variety of grasses. Hebecephalus rostratus is a grassland species occurring in southwestern Canada and northwestern United States (Beirne, 1956). It was found in nearly all of the patches sampled, but was most abundant in the native plant assemblages (esp. STCO/BOGR). Its food plants are unknown, but assumed to be grasses.
Notes on the Rarer Leafhopper Species Recorded in this Study
Nearly half (20) of the leafhopper species recorded in this study were represented by fewer than ten individuals. Some of these may have hosts that are extremely patchy in distribution, making the leafhoppers difficult to sample in a systematic fashion. Still others may be highly transient, blowing in on air currents, only to leave for new grasslands with the next weather system. A final subset may have behaviors that make them unlikely to be collected with a sweep net. The following is a discussion of some of the more unusual leafhopper species collected during this study and possible explanations for their rarity in the samples.
Frigartus frigidus is reported to feed on Artemisia frigida (Beirne, 1956). In 1991 and
1992,1 swept several individuals from grasslands containing this plant near patch 9A. The area consisted of protected canyons with vegetation dominated by Agropvron smithii and Stipa viridula. This leafhopper is large bodied and probably not especially mobile. Therefore, it may be
66 difficult to collect unless its foodplants occur in the immediate vicinity of the sampling area and are known and recognized by the sampler.
Leafhoppers of the genus Prairiana appear to be partially Subterranean and at least somewhat nocturnal (Bess, pers. obs.; Hamilton, 1994 pers. comm.). Their host plants are
Unknown, although Hamilton (1994) suspects sages f Artemesia spp.) for some of the western species. I have taken the eastern Prairiana kansana and P. angustens in habitats dominated by species of Andropogon grasses and various Asteraceae, but with no Artemisia spp. present (Bess, unpub. data). Other leafhoppers in the Gyponinae (the subfamily to which Prairiana belongs) are primarily tree and shrub feeders (Delong, 1948; Hamilton, 1996 pers. comm.). Prairiana leafhoppers are usually rare in sweep net samples, although I observed more than three dozen individuals of P. angustens at an ultraviolet light on one night in-Kentucky. This species overwinters as an adult in Kentucky where it is known from one grassland preserve (Bess unpub. data).
Leafhoppers in the genus Commellus are known to feed on Agropvron and Stipa grasses in the Midwest (Panzer et al., 1995). In my study, C. sexvitattus had a peculiar distribution, being recorded in essentially equal numbers from both a native Stipa-dominated (IOA) and a non-native
Agropyron-dominated patch (25b). It is possible that C. sexvitattus feeds on grasses from both genera in southwest Montana.
Neocolidia tumidifrons belongs to a genus distributed primarily in the American west
(Delong, 1948). It is a widely distributed species, occurring from the Pacific east through the
Great Lakes States (Delong, 1948). In the Midwest, it is associated with mesic habitats with rich
67 herbaceous growth (Bess, pers. obs.; Delong, 1948). It is likely more abundant in mesic plant assemblages, possibly ones that were not sampled in this study.
Mesamia coloradensis is a species characteristic of prairies throughout the Midwest and. northern Great Plains states (Delong, 1948). Members of the genus Mesamia are thought to feed exclusively on plants in the family Asteraceae and M. coloradensis has been reported as feeding on Artemisia frigida (Beime, 1956). Related species of Mesamia feed on the genus Helianthus in the Midwest (Bess, pers. obs.; Delong, 1948; Panzer et al., 1995).
Hardya dentata was recorded only from samples taken in the Agcr/Mesa grasslands
(Tables 3 and 4). Beirne (1956) reported this species from southern Saskatchewan and stated that it may live in litter or among plant roots. I collected many individuals of H dentata and
Stenometopielus cookei in March and April, from grasslands dominated by Agropvron smithii. A. spicatum. and Stipa viridula near the towns of Logan and Three Forks. These two leafhoppers belong to genera that are primarily Eurasian in distribution, with disjunct species (S. cookei. H. dentata and the closely related H. voungi) in the western United States and Canada (Hamilton,
1983).
Idiodonus aurantiacus was represented by two females taken in June of 1988 from site Tb in the Brin/Mesa assemblage (Appendix B). Beirne (1956) reports I. aurantiacus as being widespread, but local, in western Canada. Host plants for this genus are unreported, although species of the closely related genus Colladonus feed on a variety of herbaceous .plants, trees, and shrubs.
68 Notes on Some of the Pooled Leafhopper Genera
Several leafhopper taxa were identified only to genus because of taxonomic difficulties discussed in the Materials and Methods section. The genus Aceratagallia was discussed previously in this section, but three additional genera need to be addressed. These are
Athvsanella. Dikraneura. and Sorhoanus. Based on the male specimens examined in 1988, seven
Athvsanella species (acuticauda. attenuata, occidentalis. robustus. sinuata. terebrans, and utahna) were recorded from the STCO/BOGR plant assemblage (Appendix A). Athvsanella sinuata is reported to be a Bouteloua gracilis specialist, while A. occidentalis feeds primarily on this grass and other warm-season species (Whitcomb, et al., 1994). Athvsanella attenuata is reported to feed on wheatgrass (Blocker and Johnson, 1990) and A. acuticauda is reported to feed on bluegrass (Poa spp:). The remaining Athvsanella species are reported to be more general on other warm-season grasses (Blocker and Johnson, 1990; Whitcomb et al., 1994).
Delong (1948) reports ~60 species of Dikraneura as occurring in the Nearctic region.
Beime (1956) reports nine of these from Canada. Male specimens of this genus were identified as
D. shoshone. but many samples contained mostly females. Dikraneura leafhoppers are small, widespread species occurring in a variety of grassland types throughout Gallatin County (Bess, pers. obs.). They were most abundant in the Brin/Mesa association.
The genus Sorhoanus contains five described species in northwestern North America
(Beime, 1956), three of which (debilis. flavovirens and orientalist were identified in samples taken during this study (Appendix A). These leafhoppers were most abundant in the FEID/AGSP patches, where they were the most numerous leafhopper collected (Table 5). In contrast to their abundance in the FEID/AGSP plant assemblage, samples from the STCO/BOGR patches
69 fluctuated widely in abundance of these leafhoppers, with 16A recording the lowest number of individuals (Table 6). This STCO/BOGR patch is located south of Three Forks, some distance from any of the local mountain ranges which may contain the preferred habitats for these leafhoppers. Beime (1956) reports Sorhoanus leafhoppers from northern grassland, arctic, and mountainous habitats, reaching their southern distribution limit in the northern United States.
Whitcomb and associates (1987a) hypothesize that these leafhoppers are associated with pooid grasses. My data suggest that, of the four grassland types surveyed, these leafhoppers prefer those at higher elevations (Table 5).
70 SAMPLING EFFORT AND ADDITIONS TO THE LEAFHOPPER FAUNA OF MONTANA
Sampling Effort
A major difficulty in this study was the large number of specimens encountered and the physical similarity of many of the species examined. Initially, it was my intention to compare leafhopper samples from each of the 39 grassland patches studied by Kemp et al. (1991). This goal proved unattainable following initial counting and identification of samples from the twelve patches used in the analysis. At a rate of 20,000 specimens/12 sample patches/year (average), 39 sample patches would produce at least 65,000 leafhoppers/year, for a minimum of 260,000 specimens for a four-year study.
Therefore, I was forced to reduce the number of patches and years to a manageable level.
This reduction in the number of patches decreased the strength of conclusions that could be drawn from the analyses. A greater number of patches and a greater number of samples per patch would have allowed for the calculation of mean and variance abundance statistics for each. This would have allowed for a more detailed comparison of within patch, and within plant assemblage, variance for individual species.
Additional limitations, when working with leafhoppers, involve the method used to collect specimens. Over the years, a variety of techniques have evolved, falling into three primary categories; sweep netting, suction sampling and “passive collectors” (i.e. sticky traps, pan traps, flight intercept traps). Sweep netting and suction sampling are the most commonly used methods for sampling leafhopper assemblages in grassland ecosystems (Blocker and Reed, 1976; Brown et
71 al., 1992; Cherrill and Rushton, 1993; Cwikla and Blocker, 1981; Morris, 1973, 1981a-b, 1983;
Novotny, 1995; Waloff, 1973, 1980; WalofFand Solomon, 1972; Whitcomb et al., 1994).
Blocker and Reed (1976) found that, in a tallgrass prairie remnant, similar numbers of leafhopper species were collected using the two methods, but abundance varied greatly, with the D-vac suction samplers collecting the greatest number of individuals.
Therefore, in studies attempting to determine subtle similarity (or differences) between habitat patches, suction samplers may be more appropriate. In tallgrass prairie and wetland communities, where vegetation often exceeds shoulder height, sweep netting can be very difficult and the use of suction samplers may be more advantageous. However, this method is very time consuming and labor intensive, and may be inappropriate for studies in remote regions where equipment would need to be carried long distances. Therefore, the methods used for sampling leafhoppers depend on the characteristics of the vegetation at hand.
Given that the grasslands covered in this study never exceeded I m in height, it can generally be assumed that sweep netting was an appropriate method for sampling leafhoppers. In an eight-year study of the grasslands of Kentucky, with vegetation of similar stature, greater than
95% of the local leafhopper fauna was collected by sweep net in the first two years (Bess, unpub. data). Panzer (pers. comm.) has reported similar results in Illinois. Finally, sticky traps and pan traps can also be highly effective means of sampling Cicadellidae, but specimens can be difficult to process and identify.
As a final discussion of sampling effort and its bearing on this study, Novotny (1994), in a four-year study of 62 sites in central Europe, examined 255 populations of 101 leafhopper species represented by -105,000 individuals. In the present two year study of 12 patches in southwestern
72 Montana, over 44, 000 individuals of at least 64 leafhopper species were observed, nearly two- thirds of Novotny’s number of species on one-twentieth of the sample sites. The large number of individuals per sample and the relatively high diversity of species suggests that the sweep net sampling method used in this study was appropriate.
The lists of leafhoppers reported here probably do not represent a complete catalog of all leafhopper species potentially present at the sites sampled. In fact, 15 of the 56 taxa collected in
1988 did not appear in the 1991 samples. However, only one of the 15 made up more than one percent of the individuals collected within a plant assemblage (i.e. Rosenus cruciatus constituted
3.6% of the leafhoppers collected in the STCO/BOGR patches). Only five of 54 taxa collected in
1991 had not appeared in the 1988 samples, although only one of those five made up more than one percent of the individuals collected within a plant assemblage (i.e. Auridius auratus comprised
1.7% of the leafhoppers from the FEID/AGSP patches). The differences observed in leafhopper abundance between the sampling years may have been a result of I) the effect of sampling method on the sampler’s ability to collect rare or patchily distributed species, 2) extirpation of some of the
15 leafhopper species that had been present in 1988, 3) migration of new leafhopper species into patches after 1988, or 4) differences in yearly weather patterns. The nature of my data make it impossible to test these hypotheses.
The differences observed between samples from the two years suggest that more intensive, perhaps longer-term, sampling would be required to obtain a complete catalog of the species present within the plant assemblages covered in this study. However, for several reasons, the differences observed between the two sampling years probably do not weaken the major conclusions of this study. First, the correlation analyses for each year were not affected by the
73 absence of certain species, because only the leafhoppers collected in each year were used for that year’s analysis. Ifthe absent species had also been used, the correlations would have been artificially inflated because of multiple zero-zero data pairs. Second, few of the species observed only in one year were major components of the leafhopper fauna at their particular plant assemblage. Third, the species found only in one year were irrelevant to the analysis of correlations between leafhopper species abundance and percent cover of potential host plants.
Additions to the Leafhopper Fauna of Montana
Fox (1924) recorded 52 species of leafhoppers in 27 genera from Montana, primarily from areas around Bozeman. In contrast, at least 67 distinct leafhopper taxa in 51 genera were identified from the 1988 and 1991 samples used in my study (Table 12 and Appendix B). By comparison with Fox’s species list, 54 of these leafhopper taxa are new to the state of Montana.
Several of these (such as Athvsanella acuticauda. A. occidentalis. A. sinuata. Flexamia abbreviatta and F. flexulosal have been reported from Montana in the literature (Blocker and Johnson, 1980;
Whitcomb et al., 1994). This brings the total state leafhopper fauna to 112, a number that could easily be increased through further survey effort.
74 Table 12. The Leafhopper Fauna of Montana 1
LEAFHOPPER SPECIES Bess Fox LEAFHOPPER SPECIES Bess Fox Aceratagallia cinerea * Exitianus exitiosus * Aceratagalha novella * Elexamia abbreviata * Aceratagallia sanguinolenta * * Elexamia Jlexulosa * Aceratagallia uhleri * * Eorcipata Ioca * Agallia quadripunctata * Erigartus frigidus * Am blyseU us grex Gypona bimaculata * Athysanella acuticauda Hardya dentata * Athysanella attenuata Hebecephalus rostratus * Athysanella occidentalis Hebecephalus signatij'rons * Athysanella robusta HecaUis major * Athysanella sinuata Hecalus viridis * * Athysanella terebrans Helochara communis * Athysanella utahna Idiocerus lachrymalis Athysanus argentarius * Idiocerus snowi * Auridius auratus ** Idiocerus suturalis * Auridius helvus * Idiodonus aurantiacus * Auridius ordinatus Laevicephalus sp. * Balclutha abdominalis * Latalus misellus * * Balclutha confusa * Limotettix spp. ** Balctutha impicta * Lonatura sp. * Balclutha punctata ** Macropsis sordida * Bythoscopus rufoscutellatus * Macropsis viridis * Chlorotettix unicolor $ $ Macrosteles quadriUneatus * Cicadula quinquinotata * Mesamia coloradensis * Colladonus bolli * Mocuellus caprillus Colladonus fasciaticollis * Neokolla hieroglyphica * Colladonus geminatus ** Neokolla gothica * Colladonus montanus * * Neocolidia tumidijrons * Commellus comma * Nesosteles neglectus * Commellus semicolon * NorveUna seminuda * * Commellus sexvitattus * Norvelina tenella Cuerna striata Oncometopia lateralis Deltocephalus valens * Uncopsis distinctus * Dikraneura cameola * Orocastus labeculus Dikraneura Jieberi * Orocastus perpusillus * Dikraneura mali * Paraphlepsius occidentalis * Dikratieura shoshone * Pinumius areatus * D ikrella s p . * Prairiana cinerea * Diplocolenus conjiguratus * * Prairiana subta * Doratura stylata * Psammotettix Uvidellus * Dorycephalus platyrhynchus * Psammotettix striatus * Draeculacephala manitobiana * Rosenus cruciatus * Draeculacephala mollipes ♦ Scaphytopius acutus * Elymana circius Scaphytopius Jrontalis * Empoasca alboscripta * Sorhoanus debilis * * Empoasca aspersa * Sorhoanus Jlavovirens Empoasca Jlavescens * Sorhoanus orientalis * Empoasca mali * Stenometopielus cookei Em poasca s p . * Streptanus conjinis * Endria inimica * * Texananus cumulatus Endria rotunda * Xerophloea major Erythroneura comes * Xerophloea viridis ** Xestocephalus pulicarius * 1 Entries in BOLD are new species records for Montana T o t a l : 67 52
75 SUMMARY
1. Leafhopper samples from the three patches within each of the four plant assemblages were found to correlate significantly with one another using the combined data. The
STCO/BOGR patches were found to be the most closely associated of the four types sampled.
However, there were also a number of significant correlations between patches from different plant assemblages. These between-plant assemblage correlations usually occurred when the patches were close spatially and contained similar vegetative components (e.g. the Agropvron- dominated habitats).
2. In addition, leafhopper samples from patches within some of the plant assemblages
(e.g. the FEID/AGSP and Brin/Mesa habitats) did not correlate closely with one another in either one, or both, of the sampling years. The BrinZMesa patches did not correlate significantly with any of the other patches in analysis of the combined data.
3. The abundance of selected leafhoppers was strongly correlated with percent cover by known or suspected food plants. More intensive studies are needed to determine host plant associations for most of the leafhopper species encountered in this study. These associations are crucial to formulating an understanding of the habitat requirements of these insects.
4. Cluster analyses, based on Goodman-Kruskal’ s gamma coefficients, produced many spurious associations when comparing patches using an individual year’s data. Cluster analysis of the combined year’s data, however, produced associations supported by the correlation analysis and patterns observed in the raw data. Samples from the low elevation native grasslands
(STCO/BOGR) were found to be the most closely associated and were also closely associated
76 with those from the mid-elevation native patches (FEID/AGSP). Given the spurious associations between patches using the single years’ data, Goodman-Kruskal’s Gamma analysis should be used with great caution in situations where the data set conntains a wide range of values and numerous missing data points.
5. Leafhopper samples from patches 26A, 25b and 26b formed a distinctive outlying group unrelated to those from the remaining nine sites. The three sites contained many leafhopper species that were never, or only rarely, recorded from the other patches.
6. The results indicate that grasslands replanted to non-native plant species often harbor large numbers of a few, widespread leafhopper species. Two of those observed in this study,
Athysanus argentarius and Doratura stylata. are not native to North America and have spread rapidly from their sites of introduction in eastern Canada. Doratura stvlata was, by far, the most abundant leafhopper collected in this study and 99 percent of the individuals came from the replanted Bromus inermis/Medicago sativa grasslands. Many of the other wide-ranging leafhopper species observed in these man-made habitats are also considered agricultural pests and likely impart a tremendous stress on the plants they feed on. Some are also known vectors of plant diseases.
7. A total of 54 new leafhopper species were added to the known fauna of Montana and this number could likely be increased through further study.
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Whitcomb, R , A. Hicks, D. Lynn, K. Allred, and H. Blocker. 1987a. Geographic variation in host relationships of leafhoppers (Homoptera: Cicadellidae) in North American grasslands. Proc. 2nd Lit. Workshop on Leafhoppers and Planthoppers of Economic Importance. Provo, Utah, pp. 293-325.
Whitcomb, R , J. Kramer, M. Coan, and A. Hicks. 1987b: Ecology and evolution of leafhopper-grass host relationships in North American grasslands. Current Topics in Vector Research. 4: 125- 182.
Whitcomb, R , A. Hicks, H. Blocker, and D. Lynn. 1994. Biogeography of leafhopper specialists of the shortgrass prairie. American Entomologist 40(1): 19-35.
Whitcomb, R and A. Hicks. 1988. Genus Flexamia: New species, phylogeny and ecology. Great Basin Naturalist Memoirs 12:224-323.
Young, D. and B. Beime. 1957. A taxonomic revision of the leafhopper genus Flexamia and a new Related Genus. U.S. Department of Agriculture Technical Bulletin #1173.
83 APPENDIX A: 1988 AND 1991 LEAFHOPPER PHENOLOGY DATA FOR THE TWELVE PATCHES
84 Appendix A. 1988 Leafhopper Phenology Data.
The Stipa comata/Bouteloua gracilis Plant Assemblage Patch 7A Patch IOA Patch 16A LEAFHOPPER Sampling Dates Sampling Dates Sampling Dates TOTAL SPECIES 6/3/88 7/19/88 8/23/88 6/3/88 7/19/88 8/23/88 5/26/88 7/18/88 8/22/88 Orocastus perpusillus 432 6 1788 120 2346 Mocuellus caprillus 145 4 11 43 3 7 2 I 216 Rosenus cruciatus 91 3 4 14 I 3 40 156 Auridius helvus 63 9 72 Sorhoanus debilis 53 121 60 234 Deltocephalus valens 31 2 10 I 2 46 Hebecephalus rostratus 11 2 7 6 12 38 Athysanella utahna 8 8 135 6 157 Colladonus montanus 8 8 Athysanella occidentalis 7 12 25 57 20 121 Dikraneura spp. 7 20 27 Dorycephalus platy. 6 16 68 18 108 Aceratagallia spp. 5 86 149 13 20 22 74 I 370 Dorycephalus platyrhynchus 4 2 16 I 23 Endria rotunda 3 3 Hecalus spp. 2 I 3 Prairiana cinerea 2 2 3 3 10 Psammotettix lividellus 2 2 2 10 16 Athysanella acuticauda II Macrosteles quad. I 2 2 5 Colladonus geminatus I 6 7 Orocastus labeculus 44 5 45 84 21 199 Cuema striata 42 6 2 8 58 Flexamia abbreviata 3 3 Flexamia JlexuIosa I 2 29 32 Frigartus frigidus II I 3 Xerophloea viridis I I Stenometopiellus cookei 48 48 Commellus sexvittatus 15 15 Athysanella terebrans 13 13 Pinumius aeratus 2 2 Athysanella sp. I I Empoasca sp. I I Streptanus confmis I I Prairiana subta 2 2 Athysanella robusta II TOTAL (N) 883 218 176 2170 62 133 533 170 2 4347 NUMBER OF SPECIES 21 15 6 24 8 9 14 7 2 29
85 Appendix A. 1988 Leafhopper Phenology Data.
The Festuca idahoensis/Agropyron spicatum Plant Assemblage Patch 21A Patch 2 SA Patch 26A LEATHOPPER Sampling Dates Sampling Dates Sampling Dates TOTAL SPECIES 6/2/88 7/18/88 8/22/88 6/2/88 7/18/88 8/22/88 6/16/88 7/18/88 8/22/88 Sorhoanus debilis 223 8 159 225 6 1 5 Rosenus cruciatus 44 I 18 63 Psammotettix lividellus 34 I 79 9 123 Dikraneura spp. 14 9 15 7 2 2 4 9 Macrosteles quadrilineatus 14 I 13 28 Deltocephalus valens 11 3 22 36 Orocastus perpusillus 10 5 7 3 2 27 Athysanella acuticauda 9 15 10 34 Hebecephalus rostratus 9 2 7 I I 20 Aceratagallia spp. 7 34 38 7 4 4 65 n o 2 2 71 Hecalus spp. 7 2 5 I 10 25 Dorycephalus platy. 3 3 6 Orocastus labeculus 2 5 9 4 5 25 Xerophloea viridis 2 2 8 I I 2 16 Athysanella sinuata I I Diplocolenus con/iguratus IIII 4 Chlorotettix unicolor 114 66 7 187 Endria inimica 39 9 21 69 Athysanella utahna 20 20 Macrosteles quad. 20 23 15 58 Commellus sexvittatus 3 I 4 Collaadonus geminatus I 13 14 Mesamia coloradensis I I Mocuellus caprillus I 4 9 6 20 Dorycephalus platyrhynchus 7 2 9 Neocolidia tumidifrons 5 5 Athysanella occidentalis 2 7 9 Cuema striata 2 I 3 Auridius helvus 31 31 Elymana sp. I I Limotettix dasidus I I Limotettix kryptus 10 10 Ballana veruta 2 2 Laevicephalus sp. 2 2 Norvelina seminuda 2 2 Athysanella attenuata I I Frigartus frigidus I I Texananus spp. I I TOTAL (N) 391 263 59 342 129 8 405 191 6 17 9 4
NUMBER OF SPECIES 16 14 9 17 12 4 17 15 3 33
8 6 Appendix A. 1988 Leafhopper Phenology Data.
ThtAgropyron cristatum/Medicago sativa Plant Assemblage Patch 7b Patch 16b Patch 17b LEAFHOPPER Sampling Dates Sampling Dates Sampling Dates TOTAL SPECIES 6/3/88 7/21/88 8/23/88 5/26/88 7/21/88 8/24/88 5/26/88 7/20/88 8/25/88 Dikraneura spp. 89 2 35 Il 137 Psammotettix Hvidellus 41 113 I 360 5 1 5 Aceratagallia spp. 15 1024 374 4 9 5 6 21 14 5 8 Rosenus cruciatus 15 3 2 2 0 Colladonus geminatus 10 5 15 Hecalus spp. 9 I 14 8 18 46 I 9 7 Sorhoanus debilis 8 31 I 40 Orocastus perpusillus 7 3 10 Deltocephalus valens 6 I 7 Auridius helvus 3 3 Hebecephalus rostratus 2 I I 2 8 I 15 Dorycephalus platy. 2 2 Orocastus labeculus 2 2 7 I I 13 Diplocolenus configuratus I I Elymana sp. I I Lonatura sp. I 16 I 18 Prairiana cinerea II 2 Cuema striata 32 8 I 41 Athysanella attenuata 12 11 15 38 Macrosteles quad. II 2 Chlorotettix unicolor I I Endria inimica I I Dikrella sp. 2 2 Amblysellus grex I I Athysanella sinuata I I Neocolidia tumidifrons I I Stenometopiellus cookei I I Balclutha punctata 2 2 Nesosteles neglectus I I ' Athysanella sp. 3 Mocuellus caprillus 2 2 TOTAL (N) 213 1077 384 228 37 6 412 92 2 2451
NUMBER OF SPECIES 17 11 4 13 6 2 10 8 2 28
87 Appendix A. 1988 Leafhopper Phenology Data.
The Bromus inermis/Medicago sativa Plant Assemblage Patch 21b Patch 25b Patch 26b LEAFHOPPER Sampling Dates Sampling Dates Sampling Dates TOTAL SPECIES 6/2/88 7/20/88 8/25/88 6/2/88 7/17/88 8/22/88 6/16/88 7/17/88 8/22/88 Balclutha punctata 123 5 128 Psammotettix lividellus 89 I 5 63 18 135 18 37 3 6 6 Macrosteles quadrilineatus 43 5 4 2 I 5 5 Aceratagallia spp. 40 705 823 4 4 5 71 101 17 5 3 Sorhoanus debilis 18 29 I 87 135 Sorhoanus orientalis 16 31 59 106 Hebecephalus rostratus 3 I 4 Diplocolenus configuratus 2 48 62 108 6 28 48 I 3 0 3 Empoasca sp. 2 I I 4 Colladonus geminatus 2 8 9 19 Endria inimica 90 17 41 17 1365 179 1 7 0 9 Dorycephalus platy. 72 2 7 291 294 6 6 7 2 Doratura stylata 7 517 1521299 2 6 7 7 Latalus missellus 6 20 2 97 5 130 Cuema striata I 4 I 6 Xerophloea viridis 2 2 Dikraneura spp. 90 8 60 10 3 171 Athysanella acuticauda 2 9 18 29 Hecalus spp. 2 I 10 10 23 Macrosteles quad. I I Athysanus argentarius 33 7 40 Chlorotettix unicolor 2 5 7 Elymana sp. 2 2 Auridius auratus 29 4 33 Sorhoanus Jlavovirens 8 8 Forcipata Ioca 3 3 Commellus sexvitattus I I Mocuellus caprillus I I Elymana circius 55 17 72 Orocastus labeculus 39 39 Scaphytopius frontalis 2 2 Limotettix sp. I I Texananus sp. I I Laevicephalus sp. 3 3 TOTAL (N) 338 930 851 269 743 45 727 4241 362 8 5 0 6 NUMBER OF SPECIES 10 8 5 12 11 6 18 22 13 32
8 8 Appendix A. 1988 Leafhopper Phenology Data.
The Stipa comata/Bouteloua gracilis Plant Assemblage Patch 7A Patch IOA Patch 16A LEAFHOPPER Sampling Dates Sampling Dates Sampling Dates N
SPECIES 6/21/91 7/16/91 8/7/91 9/13/91 6/21/91 7/16/91 8/7/91 9/13/91 6/18/91 7/17/91 8/8/91 9/16/91 Mocuellus caprillus 2 1 6 2 4 2 18 10 3 l I 275 S o rh o a n u s spp. 8 9 I 7 9 4 16 189 Athysanella spp. 5 8 111 2 8 3 0 3 9 1 1 7 4 1 8 2 11 1012 Aceratagallia spp. 16 6 7 823 17 I 175 13 l 13 3 9 8 1524 Orocastus perpusillus 16 372111 I15I 516 Psammotettix lividellus 13 I 4 2 7 17 2 8 54 E m p o a sca sp. 5 I 6 Auridius ordinatus 4 5 2 i i Colladonus geminatus 4 4 Stenometopiellus cookei 3 2 8 I 32 H eca lu s spp. 2 I I 3 7 Dorycephalus platy. I 4 5 Flexamia flexulosa I 4 4 3 0 13 16 68 Orocastus IabecuIus 41 6 7 4 2 2 5 3 63 11 6 6 8 7 5 590 Chlorotettix unicolor 4 4 8 D ikra n eu ra spp. I 5 I 3 I 11 Cuerna striata 3 I I 4 9 Hebecephalus rostratus 3 I 5 I 2 I 4 17 Commellus sexvitattus I I Macrosteles quad. 6 2 6 12 26
Auridius helvus 3 3 Flexamia abbreviata 2 2 Rosenus cruciatus 3 3 Frigartus frigidus I I L im o tettix sp. I I Nesosteles neglectus I I
Deltocephalus valens I I TOTAL (N) 428 250 936 38 547 559 129 32 219 5 0 2 706 31 4377 UMBER OF SPECIES 13 8 10 7 12 9 8 9 10 6 9 7 27
89 Appendix A. 1988 Leafhopper Phenology Data.
The Festuca idahoensis/Agropyron spicatum Plant Assemblage Patch 21A Patch 2 SA Patch 26A LEAFHOPPER Sampling Dates Sampling Dates Sampling Dates N
SPECIES 6/27/91 7/18/91 8/6/91 9/16/91 6/27/91 7/18/91 8/6/91 9/13/91 6/27/91 7/16/91 8/6/91 9/13/91
S o rh o a n u s sp p . 298 201 417 70 223 95 5 1 3 0 9 D ikra n eu ra sp p . 72 I 3 56 I 13 6 152 Psammotettix lividellus 23 I 11 12 8 16 2 73 Orocoastus perpusillus 17 73 5 5 10 II 1 12 Colladonus geminatus 16 2 6 3 3 16 4 6 Auridius ordinatus 9 36 2 2 49 Macrosteles quad. 5 60 3 I 57 II 128
Athysanella sp p . 5 60 5 26 2 98 Commellus sexvitattus I 2 I 4 Mesamia coloradensis IIII 2 i 7 Orocastus IabecuIus I 21 4 12 40 24 3 57 2 1 64 Dorycephalus platy. I 55 41 38 I 66 34 20 8 65 3 3 3 2 Chlorotettix unicolor 54 20 30 4 10 5 123 Endria inimica 11 3 22 7 43 Doratura stylata 9 3 I 20 4 3 7 Auridius auratus 7 7 Mocuellus caprillus 5 7 5 2 53 21 9 3 Nesosteles neglectus 2 I 3 E m p o a sca sp. I 2 2 I 4 10 Macrosteles quad. I 6 I I 9
H eca lu s sp p . IIII 4 I 9
L im otettix sp. I 8 9
Scaphytopius sp. I I 2
Laevicephalus sp . I I Xerophloea viridis 3 3 6 12 Neocolidia tumidifrons I I Cuerna striata 2 4 6 12 Diplocolenus config. 2 I 4 7 Balclutha punctata I ■: '■ .. Forcipata Ioca I I Frigartus frigidus I I Elymana circius 18 18
Auridius heIvus I I Latalus missellus I I
Paraphlepsius sp. I I TOTAL (N) 454 547 92 120 518 257 72 106 274 309 121 6 2 8 7 6 NUMBER OF SPECIES 12 21 13 7 11 14 9 9 11 19 9 4 35
90 Appendix A. 1988 Leafhopper Phenology Data.
The Agropyron cristatum/Medicago sativa Plant Assemblage Patch 7 b Patch 16b Patch 17b LEAFHOPPER Sampling Dates Sampling Dates Sampling Dates N
SPECIES 6/21/91 7/16/91 8/7/91 9/16/91 6/18/91 7/17/91 8/8/91 9/16/91 6/18/91 7/17/91 8/8/91 9/16/91 Sorhoanus spp. 26 14 3 43 Psammotettix lividellus 15 6 2 29 4 17 6 39 I 25 2 146 Aceratagallia sp p . 13 79 806 42 138 6 5 31 1 1 2 0 D ikra n eu ra sp p . 11 3 6 6 4 I I 6 38 H eca lu s sp p . 6 4 I I 6 8 22 8 56 Mocuellus caprillus 6 6 Orocastus perpusillus 5 II 7 Macrosteles quadrilineatus 3 2 I 8 I 2 17 Colladonus geminatus 2 2 Rosenus cruciatus I I Athysanella sp p . 125 4 5 237 63 5 106 3 548 Dorycephalus platy. 6 6 Orocastus labeculus 2 35 19 2 58 Commellus sexvitattus I I Cuerna striata I I Stenometopiellus cookei I I Hebecephalus rostratus III 3 Doratura stylata 5 5 Hardya dentata 3 I 4 Macrosteles quad. 2 2 Amblysellus grex I I TOTAL (N) 88 221 819 11 57 326 249 22 56 138 68 11 2066 NUMBER O F SPECIES 10 8 6 4 7 6 7 5 5 7 5 4 20
91 Appendix A. 1988 Leafhopper Phenology Data.
The Bromus inermis/Medicago sativa Plant Assemblage Patch 21b Patch 25b Patch 26b LEAFHOPPER Sampling Dates Sampling Dates Sampling Dates N
SPECIES 6/27/91 7/18/91 8/6/91 9/16/91 6/27/91 7/16/91 8/6/91 9/16/91 6/27/91 7/16/91 8/6/91 9/13/91 D ikra n eu ra sp p . 89 16 107 25 10 55 72 14 32 6 426 Colladonus geminatus 78 7 3 4 2 5 6 2 107 S o rh o a n u s sp p . 35 35 i 68 52 12 203 Psammotettix lividellus 13 I I 9 8 23 8 57 112 48 33 19 332 Macrosteles quadrilineatus 4 65 I 11 48 12 3 3 147 Diplocolenus configuratus 3 13 8 103 94 86 2 64 58 431 Athysanella sp p . 2 I 18 7 28 Amblysellus grex II 2 19 42 123 188 Aceratagallia sp p . 92 449 108 128 I 36 78 71 963 Endria inimica 18 2 I 1682 17 4 4 2933 1158 14 5833 Doratura stylata 16 10 11 2576 68 4278 1983 I 8943 Dorycephalus platy. I I Nesosteles neglectus I I Commellus sexvitattus 2 8 3 13 Latalus missellus I 16 4 5 53 33 112 Athysanus argentarius 18 10 42 25 95 Auridius ordinatus 7 32 13 52 Elymana circius 6 28 17 51
H eca lu s sp p . 3 20 6 29 Macrosteles quad. 2 13 6 3 24 Chlorotettix unicolor 4 4 Orocastus labeculus I I Balclutha punctata I 7 3 11
L im otettix sp . 8 8
Scaphytopius sp. 2 4 6 Cuerna striata I I Mesamia coloradensis I I TOTAL (N) 225 142 473 205 272 4622 214 174 328 7770 3470 116 18011 NUMBER OF SPECIES 8 7 7 5 10 16 13 9 8 19 18 8 27
92 APPENDIX B: THE LEAEHOPPER SPECIES COLLECTED DURING THIS STUDY
93 Appendix B. The Leafhopper Species Collected during this Study.
subfamily AGALLDNAE subfamily DELTOCEPHALINAE cont'd Aceratagallia sanguinolenta Provancher genus Scaphytopius Ball Aceratagallia uhleri (Van Duzee) Sorhoanus debilis (Uhler) Sorhoanus flavovirens (Gillette and Baker) subfamily BALCLUTHINAE Sorhoanus orientalis (Delong and Davidson) Nesosteles neglectus (Delong and Davidson) Stenometopielus cookei (Gillette) Balcluthapunctata (Thunb.) Streptanus conjinis (Rent.) genus Texananus Ball subfamily DELTOCEPHALINAE Amblysellusgrex (Oman) subfamily DORYCEPHALINAE Athysanella (Amphipyga) acuticauda Baker Dorycephalus platyrhynchus Osborn Athysanella (Amphipyga) attenuata Baker Athysanella (Amphipyga) occidentalis Baker subfamily HECALEfAE Athysanella (Athysanella) robusta (Osborn) Hecalus major (Osborn) Athysanella (Gladioneura) sinuata (Osborn) Hecalusviridis (Uhler) Athysanella (Athysanella) terebrans (Gillette and Baker) Athysanella (Athysanella) utahna (Osbom) subfamily IASSEfAE Athysanus argentarius Metcalf Prairiana cinerea (Uhler) Auridius auratus (Gillette and Baker) Prairiana subta Ball Auridius helvus (Delong) Auridius ordinatus (Ball) subfamily LEDREfAE Chlorotettix unicolor (Fitch) Xerophloea viridis (Fabricius) Cicadula quinquinotdta (Boh.) Colladonus geminatus (Van Duzee) subfamily NEOCOLIDIEfAE Colladonus montanus (Van Duzee) Neocolidia tumidifrons Gillette and Baker Commellus semicolon Hamilton Commellus sexvitattus (Van Duzee) subfamily TETTIGELLEfAE Deltocephalus valens Beamer and Tuthill Cuema striata (Walker) Diplocolenus configuratus (Uhler) Doraturastylata (Boh.) subfamily TYPHLOCYBEfAE Elymana circius Hamilton Dikraneura shqshone Delong and Caldwell Endria inimica (Say) gems Dikrella Oman Endria rotunda (Beamer) genus Empoasca Walsh Flexamia abbreviata (Crumb) Forcipata Ioca (Delong and Caldwell) Flexamia flexulosa (Ball) Frigartusfrigidus (Ball) Hardya dentata (Osborn and Ball) Hebecephalus rostratus Beamer and Tuthill Idiodonus aurantiacus (Provancher) gem sLaevicephalus Delong Latalusmisellus (Ball) gems Lonatura Osbom and Ball Macrosteles quadrilineatus (Forbes) Mesamia coloradensis Gillette and Baker Mocuellus caprillus Ross and Hamilton Norvelina seminuda (Say) Orocastus labeculus (Delong) Orocastus perpusillus (Ball and Delong) Paraphlepsius occidentalis (Baker) Pinumius areatus (Stal) Psammotettix lividellus (Zettinger) Rosenus cruciatus (Osborn and Ball)
94