View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by SHAREOK repository Technical Bulletin No. 5 December, 1938 OKLAHOMA AGRICULTURAL AND MECHANICAL COLLEGE AGRICULTURAL EXPERIMENT STATION Lippert S. Ellis, Acting Director An Ecological Survey of the Orthoptera of Oklahoma By MORGAN HEBARD Philadelphia Museum of Natural History Curator of Orthoptera Stillwater, Oklahoma FOREWORD By F. A. Fenton Head, Department of Entomology Oklahoma A. and M. College The grasshopper problem in Oklahoma has become of increasing importance in recent years, and because these insects are among the state's most destructive agricultural pests the Oklahoma Agricultural Experiment Station has taken up their study as one of its important research proj­ ects. An important step in this work is a survey to determine what species occur in the State, their geographic distribution, and the relative import­ ance of different species as crop and range pests. The present bulletin represents such a survey which was made during a particularly favorable year when grasshoppers were unusually abundant and destructive. The major portion of the State was covered and collections were made in all of the more important types of habitats. To make the stup.y more complete, all of the Orthoptera have been included in this bulletin. One hundred and four species and 12 subspecies or races are listed for the State, including 17 which are classed as in­ jurious. The data are based upon over seven thousand specimens which were collected during the period of the investigation. This collection was classified by Doctor Morgan Hebard, Curator of Orthoptera, Philadelphia Museum of Natural History, who is the author of this bulletin. AN ECOLOGICAL SURVEY OF THE ORTHOPTERA OF OKLAHOMA* MORGAN HEBARD The great abundance of destructive species of grasshop­ pers in Oklahoma since 1936 prompted the organization of a field survey during the summer of 1937 in which emphasis was placed on collecting Orthoptera. Collections were made in 56 localities distributed rather widely over various parts of the State (Fig. 1). Work was begun June 4 and ended August 18, but was nearly continuous only in late June and through July. In addition to making general collections of Orthoptera, grass­ hoppers were collected from eight different environments. Ten collections were made ::J.t different dates from each habitat and approximately 100 specimens were collected at a time. For the 17 dominant specie3, this meant a total of from 483 to 1033 specimens per environment. The following is a brief description of each environment: A. Pasture. Native grass areas grazed by livestock, usually with but few trees. (Fig. 2.) B. Range or waste land. Sage, blackjack, or tall grass areas, often sparsely wooded. (Fig. 3.) C. Alfalfa. Alfalfa hay fields at any stage of maturity. D. Roadside. Areas immediately adjoining roads or highways; i. e., all land along road outside the field fences or field boundaries; vegetation usually weeds, sometimes grass. E. Corn. Cultivated corn. F. Cotton. Cultivated cotton. G. Stubble. Wheat (or occasionally oat) stubble as left by grain binder or combine, with or without grain shocks still remaining on field. H. Weeds along stream. Weeds and similar vegetation imme­ diately adjoining a stream (Fig. 4.) • The collections on which this paper is based were made by John Standish Rnd Robert Kaiser, students in entomology, Oklahoma A. and M. College, and the author gratefully acknowledges their assistance. The photographs to illustrate typical habitats were taken expressly for this bulletin by G. A. Bieberdorf, assistant pro­ fessor of entomology at the Oklahoma A. and M. College. (5) Table I.-Distribution of Injurious Species of Grasshoppers in Eight Envii·onments, Oklahoma, 1937. r:'"" ENVIRONMENT .. I if ! § ..... <s 0 Species " ~- "... g:, ....... ~ § . <::"' 't:l><'" '"~ ~ 0:: ~ z 0 .<:> "'" "0 .:: ~ '"~ ~ "' "'0 ... 0 li)E-< ?;' p.."' "' 0 0 :;:: p.. ...... "' ~"' '"~ ~ 0 0 1il"' '""' '"E-< !;:) .,.. Merm.iria m.aculipennis m.aculipennis 25 12 10 32 79 1.4 -0 ~ Phlibostrom.a quadrim.aculatum. 30 13 12 1 3 11 70 1.2 !;:) Ageneotettix deorum. deorum. 58 16 2 50 11 3 140 2.5 ~ Aulocara elliotti 36 4 4 27 1 64 4 140 2.5 <Q.... Spharagem.on collare 40 52 5 5 14 17 85 218 3.8 n· Trimerotropis citrina 3 7 32 20 77 2 6 147 2.6 ~.,.... H esperotettix speciosus 79 27 4 15 24 8 33 190 3.3 .:::.... M elanoplus glaucipes 2 36 3 3 1 4 10 45 104 1.8 ~ Mel(moplus m.exicanus m.exicanus 33 22 66 16 14 108 67 22 348 6.0 l>1 H Melanoplus joedus iselyi 92 35 53 90 39 20 71 173 573 10.0 'd ~ ~ Melanoplus joedus fluviatilis 135 5 2 v 57 204 3.6 .... M elanoplus packardii 117 86 178 124 6 54 78 643 11.2 ~- Melanoplus angustipennis im.piger 162 151 18 83 16 69 110 26 635 11.1 ~ .,....;::: Melanoplus bispinosus 28 12 26 54 3 16 33 1 173 3.0 t/.l Me~anoplus bowditchi bowditchi 2 108 3 113 1.9 .,.... !;:) Melanoplus dijjerentialis 151 115 382 151 426 101 134 134 1,594 27.9 .,.... 0"'· M elanoplus bivittatus 40 49 52 36 53 57 40 25 352 6.2 ;::: ---~·----- --··-- - 1033 738 815 735 597 606 716 483 5,723 * The total numhPr rer.orrlPil fnr Pa:r.h hahitat. dOf~s not necessarily coincide with the number given in the text under the discussion of each species. This is bf'cause in many cases no record was given of the environment or the specimen was collected in a plant association not given in the tnble. The habitat collection was kept separate from the general collection and no records are available except locality and date. The Orthoptera of Oklahoma 7 Seventeen species of gra;:,shoppers representing 5,723 speci­ mens were sufficiently abundant to indicate they were doing serious damage. (Table 1). It was evident that members of the genus Melanoplus were Yastly more harmful than those o£ any other genus. Among these, difjerentialis was by far the most abundant, followed by the races of toedus, a large and vigorous species characteristic of the Great Plains. Next in abundance were packardii, a species of similar size and dis­ tribution, and angustipennis impiger, which averages some­ what smaller (as is true for typical toedus fluviatilis). Next to these in numbers was bivittatus, then mexicanus mexicanus. The latter, though a much .smaller insect, merits close obser­ vation. In the past, spretus, believed to be the migratory phase of this species, was capable of doing far greater injury to ------~------------,------------, 21 ~ 2 Figure 1.-Map of Oklahoma showing locations where collections were made. See list on page 11. 8 Oklahoma Agricultural Experiment Station Figure 2.-Typical pasture. See description of habitat A, page 5. almost all vegetation than any other form of grasshopper in­ habiting temperate North America. Its last serious outbreaks occurred in the eighties. In addition to the species listed in the table, the following were present in much smaller quantities, though in sufficient numbers to be termed abundant: Chortophaga viridijasciata, Hippiscus rugosus, Dissosteira carolina, Spharagemon equale, Schistocerca lineata, Aeoloplvs turnbulli bruneri, Hesperotettix viridis viridis, Hesperotettix viridis pratensis, Melanoplus je­ mur-rubrum jemur-rubrum, Melanoplus joedus joedus, Me­ lanoplus arizonae and Melanoplus jlavidus. A study of the relative numbers of the 17 dominant species collected in eight habitats shows that for the period during which this survey was made M. dijjerentialis was the most abundant species in alfalfa, roadside, corn and wheat stubble, and second in numbers in the other habitats. M· angustipennis impiger was dominant in pasture and range and second in wheat stubble, M. mexicanus mexicanus was most numerous in cotton and third in alfalfa and M. joedus iselyi The Orthoptera of Oklahoma 9 was dominant in the weeds along streams. Of economic im­ portance as range and pasture species were M. angustipennis: impiger, M. difjerentialis, M. joedus fluviatilis (pasture only), M. packardii, M. bowditchi bowditchi (range only), M. joedus iselyi and Hesperotettix speciosus. The three most important species attacking alfalfa were M. differentialis, M. packardii and M. mexicanus mexicanus. Corn was attacked by M. dif­ jerentialis, M. bivittatus and M. joedus iselyi and cotton by M. mexicanus mexicanus, M. dif!erentialis and Trimerotropis ci­ trina. SYSTEMATIC TREATMENT It should be observed that only the Acrididae (or true grass­ hoppers) can here be considered in anything like a normal ratio, as species of the other families of Orthoptera might be present in great numbers though relatively few might be seen, due either to their usually more secretive habits or the fact that very many of them arc nocturnal. It should also be re­ membered that adult grasshoppers of various species are pres­ ent in the State from early April to late November, and that many of these earlier species may have either disappeared at Figure 3.-Range country. See description of habitat B, page 5"" 10 Oklahoma Agricultural Experiment Station Figure 4.-Wooded area along stream. See description of habitat H, page 5. the time the collections wer~ made or at least had greatly di­ minished in numbers. This iE: true for Melanoplus mexicanus mexicanus and M. bivittatus. The former species developed a second generation in 1937 and became very abundant after the last field collections were made. In Oklahoma, the major problem concerns the grasshop­ pers only. In other portions of the United States, however, other Orthoptera are known to be very harmful at times. In­ cluded in this group are the mole-crickets (Scapteriscus) in the Southeast, katydids (Anabrus, a flightless terrestrial species) in the West, and, locally, tree-crickets (Oecanthus). The latter mainly concern the horticulturist.