Great Basin Naturalist

Volume 46 Number 4 Article 17

10-31-1986

Comparison of from burned and unburned areas after a range fire

James D. Hansen Utah State University

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Recommended Citation Hansen, James D. (1986) "Comparison of insects from burned and unburned areas after a range fire," Great Basin Naturalist: Vol. 46 : No. 4 , Article 17. Available at: https://scholarsarchive.byu.edu/gbn/vol46/iss4/17

This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Great Basin Naturalist by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. COMPARISON OF INSECTS FROM BURNED AND UNBURNED AREAS AFTER A RANGE FIRE

James D. Hansen'

Abstract. — communities at recently burned and unburned sites in the Great Basin of northwestern Utah were studied by weekly sampling with pitfall and Malaise traps. More specimens were consistently collected at the burned site, although the numbers of species between the sites were about equal a month after the fire. Flying insects showing no preference for the sites were sciarids, phorids, and leiifminer (all Diptera). Insects preferring the unburned site were mostly entomophagous flies such as pipunculids, chamaemyiids, and tachinids. Insects more common at the burned site were mosquitoes and phytophagous species of lygaeid bugs, leafhoppers, and moths. Seasonal trends in relative abundance of major families of flying insects are reported. Ground survivors included gryllacridids, carabids, tenebrionids, and ants. Silphids and buprestids immigrated into the burned area soon after the fire. Interrelationships between the burned area and the insect community are dicussed.

Fire is an important component of the Utah, north of the Great Salt Lake between rangeland ecosystem in the western United the Wildcat Hills and the Raft River Moun- States. By consuming excess organic material, tains. Elevation was between 1,340 and 1,460 range fires release nutrients for future m. Predominant native plants were big sage- growth, stimulate regrowth of preferred for- brush, Artemisia tridentata Nutt.; winterfat, age species, and eliminate undesired plants. Ceratoides sp.; rabbitbrush, Chnjsothamnus In many areas, repeated burnings perpetuate sp.; and western wheatgrass, Pascopyrum grasslands. smithii (Rydb.) Love. Major introduced spe- The effect of range fires on resident insect cies were cheatgrass, Bromiis tectorum L.; communities, however, is poorly known. crested wheatgrass, Agropyron spp.; and in- Most of the previous research on the relation- termediate wheatgrass, Thinopyrum inter- ship between fire and insects were from the medium (Host). midwest. Rice (1932) studied the influence of On 7 July 1983 lightning started a range fire fire on , including insects, in an Illi- that burned at least 20,000 contiguous nois prairie. Cancelado and Yonke (1970) re- hectares. The fire, fueled by senescent cheat- ported the effect of prairie fire on insects in grass, was hot enough to destroy most of the Missouri. Several studies on prairie burns and sagebrush cover. insect populations were conducted in Kansas The unburned (comparison) site, 24 km (Nagel 1973, Knutson and Campbell 1976, west of Snowville, Utah, was established on Evans et al. 1983, Seastedt 1984). 20 May 1983 in an old plot (ca one hectare) of The present study sought to ascertain insect intermediate wheatgrass surrounded by sage- survival immediately after a range fire in the brush and rabbitbrush. Great Basin and detect immigration of the The burned site, ca 11 km south of the first potential phytophagous colonizers. Sec- site at least 3 within the ondary objectives were to assess the immigra- unburned and km of the burn, was similar in slope and tion of predaceous and parasitic insects after a boundary elevation to the unburned site. Insects were fire, and to determine the seasonal activity of first sampled a week after the fire. Notes on adults of major insect groups in typical burned recorded during the sea- and unburned areas. revegetation were son. Insects were collected by two methods. Materials and Methods Malaise traps, used for flying insects, were The study area was in Box Elder County, made of off-white polyester marquisette ma-

'USDA-ARS, Crops Research Laboratory. Utah State University, Logan, Utah 84322. Current address; U.S. Department of Agriculture. Agricultural Research Service, Tropical Fruit and Vegetable Research Laboratory, P.O. Box 4459, Hilo, Hawaii 96720.

721 722 Great Basin Naturalist Vol. 46, No. 4

16 I UNBURNED w 14

CO BURNED z I m 12 O m 10 Q. CO 8 H

6

4

2

-I -r-p 1 n 1 3 10 17 24 16 23 5 13 20 4 JUNE JULY AUG SEPT OCT NOV

Fig. 1. The number of specimens in weekly Malaise trap collections from unburned site and burned sites in Box Elder County, Utah, during 1983.

terial, square in configuration with four cen- Specimens from Malaise and pitfall traps tral vanes, and each topped with a clear acrylic were collected weekly from the establishment collecting tube. The traps were purchased of study sites until 4 November 1983. Collec- from BioQuip Products (P. O. Box 61, Santa tions were not made during the weeks of 19 Monica, California 90406).^ A trap was placed August and 27 October because of severe rain. in the grassy area of the unburned site and Insects were identified at least to the family another at the burned site. level and separated by morphospecies (Janzen Pitfall traps were used to sample ground and Schoener 1968, Allan et al. 1975). Genus inhabiting insects. The trap, similar to that and, when possible, species were determined described by Morrill (1975), was composed of for abundant specimens. Moths could not be a 4-oz plastic cup that collected specimens segregated into families because of the poor that fell through a funnel made of a 7-oz ta- condition of samples from the Malaise traps. pered plastic cup with the bottom cut out. This whole unit was housed in a 16-oz plastic Results cup and buried to surface level. At the un- burned site, seven traps were arranged on a Althought the fire severely damaged vege- hnear transect ca 20 m apart in the shrubby tation, regrowth was evident by 29 July. In area; additional pitfalls were placed under and early September cheatgrass was plentiful and near the Malaise trap. At the burned site, 10 averaged ca 5 mm in height; sagebrush and traps were ca 10 m apart along a linear transect rabbitbrush also recovered. In the following near the Malaise trap. months, western wheatgrass became the domi- nant grass for the remaining sampling period. Collection data from the Malaise traps Mention is of trade name for identification only and does not imply ; ndorsement to the exclusion of other products that may be suitable. showed that the number of specimens col- October 1986 HANSEN: Insect Ecology 723

140 UNBURNED BURNED 120

100

80

60

40

20

17 24 5 12 24 16 23 5 13 20 4 JUNE JULY AUG SEPT OCT NOV

Fig. 2. The number of morphospecies identified from weekly Malaise trap collections either from an unbumed site

• a burned site in Box Elder County, Utah, during 1983.

lected at the unbumed site peaked during the density, they do indicate relative abundance. last two weeks in June and was higher than the Major families, determined by the number of burned site in the first two collections after specimens, were grouped into three classes: the fire (Fig. 1). More specimens were consis- those showing no preference or those clearly tently collected at the burned site, with the preferring either of the sites. Hymenoptera greatest amount in August and September. were clumped into two groups. Parasitic Hy- Numbers declined from mid-September menoptera contained Braconidae, Ichneu- through the fall. monidae, Mymaridae, Eulophidae, Encyr- Nearly all the specimens collected by the tidae, Eupelmidae, Eucharitidae, Pterom- Malaise traps were adults from the winged alidae, Eurytomidae, Chalcididae, Proc- orders (Homoptera, Hemiptera, Lepi- totrupidae, Ceraphronidae, Diapriidae, Sce- doptera, Diptera, and Hymenoptera). Abun- lionidae, Chrysididae, Bethylidae, Dry- dant families, however, were arranged by inidae, Tiphiidae, and Mutillidae. Pre- species. The number of species collected at daceous Hymenoptera contained mainly the unbumed site remained about the same pompilid and sphecid wasps. before and three weeks after the fire (Fig. 2). Insects having no site preference were Scia- Similar numbers of species were then col- ridae (mostly Lycoriella spp.), four unidenti- lected at the burned site from August onward. fied species of Phoridae, 16 species of Numbers at both sites decreased during fall. Agromyzidae, and many parasitic Hymen-

To determine site preference, the collec- optera (Table 1). Those preferring the un- tion data were grouped taxonomically. Most bumed site were 15 species of Bombyliidae, 3 specimens were sorted to family only because species of Pipunculidae (most were Pipun- of insufificient numbers at the morphospecies culus sp. and Prothecus sp.), 6 species of level. Abundant families, however, were ar- Chamaemyiidae, and 39 species ofTachinidae ranged by species. Although Malaise traps (with Hyalomya aldrichii Townsend and were not intended to measure population Paradidyma singularis Townsend the most 724 Great Basin Naturalist Vol. 46, No. 4

Table 1. Insects having no preference between unbumed and burned sites in Box Elder County, Utah, during 1983 as shown by weekly Malaise trap collections.

Collection October 1986 HANSEN: Insect Ecology 725

Table 2. Insects preferring the unburned site in Box Elder County, Utah during 1983 as shown by weekly Malaise trap collections

Collection 726 Great Basin Naturalist Vol. 46, No. 4

Table 3. Insects preferring th( ?d site in Box Elder County, Utah, during 1983 as shown by weekly Malaise trap collections.

Collection October 1986 HANSEN: Insect Ecology 727 bids (Parmenter and MacMahon 1984). investigations of the USDA-ARS and the Utah The collection data suggested that A. immacii- Agricultural Experiment Station, Logan, Utah lata is attracted to stressed environments be- 84322. Approved as Journal Paper No. 3027. cause specimens were only found in pitfall traps on the burned site. Many buprestid species are Literature Cited sensitive to smoke and heat, and the beetles may D., Allan, J. H. J Alexander, and R Greenberg. 1975. Fo- have been attracted by volatiles from burned liage communities of crop and fallow fields. Decologia(Berl.) 49-56. winterfat, the host plant for the larvae. Further- 22: Cancelado,R.,andT. R.Yonke 1970. Effect of prairie burn- larvae survive feeding on the roots more, may by ing on insect populations. J. Kansas Entomol. Soc. 43: of damaged plants. 274-281. Evans, W., R. A. Pitfall traps commonly collected two other E. Rogers, and D J. Opfermann. 198.3. Sam- pling grasshoppers (Orthoptera: Acrididae) on burned types of insects. Silphids may have entered pit- and unburned tallgrass prairie; night trapping vs. fall traps to feed on the dead bodies of other sweeping. Environ. Entomol. 12: 1449-1454. insects. No apparent reason explained why the Evans, F. C, and W. W. Murdoch 1968. Taxonomic compo- omnivorous Jerusalem crickets, S. fuscus, were sition, trophic structure, and seasonal occurrence in a grassland insect community. Anim. Ecol. 37: not collected at the unburned site. J. 259-273. The present study raises several questions Evans, F C. and D F Owen 1965. Measuring insect flight about the relationship between fire and the in- activity with a Malaise trap. Pap. Michigan Acad. Sci., sect community. For example, why were so Arts, and Letters 50: 89-94. Greenslade, P M 1964. Pitfall trapping as a method for many predaceous and parasitic hymenopterans J populations studying of Carabidae (Coleop-tera). J. in the burned area (Table 3), especially when so Anim. Ecol. 33:301-310. few flowers and, presumably, potential hosts Hawkins.B A, and E.A.Cross 1982. Patterns of refaunation were present? Why did parasitic flies avoid the of reclaimed strip mine spoils by nonterricolous . Environ. Entomol. 11:762-775. burned site that contained abundant potential

Hewitt, G. B , and W. H Burleson. 1976. An inventory of hosts? groups, particularly leaflioppers Some arthropods from three rangeland sites in central Mon- and moths, apparently are attracted to burned tana. J. Range Manage. 29: 232-237. areas, but unfortunately their means of orienta- Janzen, D. H, and T W Schoener. 1968. Differences in insect abundance and diversity between wetter and tion are not well known. Although only adults drier sites during a tropical drv season. Ecology 49: were examined in this study, this is the main life 96-110. stage at which many insects disperse into various Knutson, H., and J B. Campbell. 1976. Relationships of habitats. grasshoppers (Acrididae) to burning, grazing, and range sites of native tallgrass prairie in Kansas. Proc. Although fire is a common management tool Tall Timbers Conf Ecol. Anim. Control Habitat Man- for rangeland, this study raises important con- age. 6: 107-120. siderations of its use. Herbivorous insects seem Luff, M L 1975. Some features influencing the efficiency of pitfall traps. Oecologia (Berl.) 19: 345-357. very attracted to burned sites, yet their natural

Matthews, R W., and J. R. Matthews 1971. The malaise enemies, particularly parasitic flies, avoid those trap: its utility and potential for sampling insect popu- locations. Consequently, vegetative regrowth is lations. Michigan Entomol. 4: 117-122. highly susceptible to plant feeders and may be so Morrhx, W L 1975. Plastic pitfall trap. Environ. Entomol. severely stressed as to inhibit stand reestablish- 4; 596.

Murdoch, W. W , F. C. Evans, and C. H. Peterson. 1972. ment. The abundance of insect herbivores also Diversitv and pattern in plants and insects. Ecology presents a danger to reseeding programs. Young 53: 819-828. vegetation is often highly susceptible to insect Nagel, H G. 1973. Effect of spring prairie burning on herbiv- orous and non-herbivorous arthropod populations. herbivory. Obviously, more research is needed J. Kansas Entomol. Soc. 46: 485-496. to determine the long-term effects of range fires Parmenter, R R , and J A. MacMahon. 1984. Factors influ- on insect and plant communities. encing the distribution and abundance of ground- dwefling beetles (Coleoptera) in a shrub-steppe Acknowledgments ecosystem: the role of shrub architecture. Pedobiolo- gia 26: 21-34. Appreciation is extended to: D. C. Nielson, Rice, L. A. 1932. Effect of fire on the prairie communi-

C. L. Nowak, and S. F. Parker for their assis- ties. Ecology 13: 392-401. Seastedt, T R 1984. Microarthropods of burned and un- tance; W. J. Hanson, G. E. Bohart, and F. D. burned tallgrass prairie. Kansas Entomol. Soc. 57: Parker for identifying specimens; and USDI, J. 468-476. Bureau of Land Management for use of study Thom.\s, D.B., AND F G.Werner 1981. Grass feeding insects sites. of the western range: an annotated checklist. Univ. This research was the result of cooperative Arizona Tech. Bull. 243; 1-50.