Great Basin Naturalist Memoirs Volume 12 Research in the Auchenorrhyncha, Article 6 Homoptera: A Tribute to Paul W. Oman 10-1-1988 Some aspects of the biology, morphology, and evolution of leafhoppers (Homoptera: Cicadelloidea and Membracoidea) J. W. Evans Australian Museum, Sydney, N. S. W., Australia Follow this and additional works at: https://scholarsarchive.byu.edu/gbnm Recommended Citation Evans, J. W. (1988) "Some aspects of the biology, morphology, and evolution of leafhoppers (Homoptera: Cicadelloidea and Membracoidea)," Great Basin Naturalist Memoirs: Vol. 12 , Article 6. Available at: https://scholarsarchive.byu.edu/gbnm/vol12/iss1/6 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 Memoirs by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. SOME ASPECTS OF THE BIOLOGY, MORPHOLOGY, AND EVOLUTION OF LEAFHOPPERS (HOMOPTERA: CICADELLOIDEA AND MEMBRACOIDEA) J. W. Evans' Abstract —This article summarizes some observations of a varied nature on the biology, morphology, and evolution of the Cicadelloidea (Cicadellidae, Hylicidae, Eurymelidae) and Membracoidea(Membracidae, Aetalionidae, Biturri- tidae, Nicomiidae). These observations, made over a period of more than half a century, have previously been recorded at different times, but lie buried in the literature. It is hoped that their interest will justify repetition and draw attention to some promising lines of research. Biology ulatum Linnaeus (Evans 1946b). In his discus- sion of the function of the songs of various Food Plant Associations Auchenorrhyncha, Ossiannilsson described As Southwood (1961) has pointed out, in- some as being "calls of courtship." Subse- sects have a particularly close association with quently, I noted the presence of well-devel- plants belonging to the predominant flora of oped tymbals in nymphs belonging to every the time. Thus, most Australian cicadelloids instar but the first in both sexes of A. reticida- feed on eucalypts and numerous membracids tiim (Evans 1957). As, presumably, nymphal on acacias. Of particular interest are relict song cannot have a sexual significance, it may insects that feed on representatives of ancient serve an assembling purpose since aetalionids are insects. floras. Examples are Koebelia californica gregarious However, amongst the Baker on conifers in California and Cornutipo Eurymelidae, which are likewise gregarious, spp. (Eurymelidae) on representatives of the I have been unable to find any trace of tym- Proteaceae in Australia. The Cephalelini, a bals. Nevertheless, prior to mating, eu- tribe of the Ulopinae which have an Antarctic rymelids indulge in a prolonged courtship distribution, provide another example, for (Evans 1931). their feeding seems to be restricted to an an- Tymbal sound production occurs among cient family of plants, the Restionaceae, in representatives of all the superfamilies of the Australia, South Africa, and New Zealand. Auchenorrhyncha, and even in the Changes of food plants have recently oc- Cicadoidea it is not confined to one sex since curred in the Tartessinae (Cicadellidae). females of Tettigarcta can "sing." Thus, it These are primarily eucalypt feeders, but must have been a feature acquired in early some have become adapted to living in tropi- Mesozoic, if not Palaeozoic, times (Evans cal rain forests and have taken to feeding on 1941). Moreover, it would seem that during other kinds of trees (F. Evans 1981). the early Mesozoic some Auchenorrhyncha were capable of stridulation. This is supposed Sound Production and Courtship because some Upper Triassic Homoptera (e.g. , Eoscartoides bryani Evans) have stridu- Ossiannilsson, in his notable study of the latory areas on the proximal costal area of their "songs" of Homoptera, was the first to draw (Evans 1961). attention to the presence of tymbals in insects tegmina of both sexes belonging to the Cicadelloidea, Oviposition Cercopoidea, and Cicadoidea (Ossiannilsson 1949). Previously, I had noted the presence of When ovipositing, the majority of leafhop- structures that I described as "resembling pers insert their eggs into plant tissue, either tymbals" on the first abdominal segment of singly or in batches. In the latter case, the Darthula hardwickii Gray and Aetalion retic- eggs are covered with secretions that harden 'Australian Museum, Sydney, N.S.W., Australia. Present address; 47 Bundarra Road, Bellevue Hill, Sydney 2023, Australia. 61 62 Great Basin Naturalist Memoirs No. 12 on exposure to the air. The eggs of aetahonids loides punctata [Signoret]) (Evans 1966). and of some bitturitids and membracids are The largest known leaffiopper, the aetal- contained in oothecae situated on the surface ionid Darthula hardwickii Gray, has a length of the plants. Because the AetaHonidae are an of 28 mm, of which the apical 12 mm in both ancient group of insects, it might be thought sexes consists of the prolonged ninth abdomi- that such a method of oviposition predated nal segment. The smallest leafhoppers are egg insertion in plant tissue. However, this is comprised in the Typhlocybinae (Cicadelli- improbable, as the last-named method is dae), some species of which are no more than shared with insects belonging to the super- 2 mm long. Evolutionary development seems families of the Auchenorrhyncha; and eggs, to be frequently accompanied by increase in whether laid inside plants or on their surface, size. Thus, for example, in the Eurymelidae, are equally subject to heavy parasitism. the largest species are seemingly the most recently evolved (e.g., Eunjmelops generosa Gregariousness and Ant Attendance [Stal]). While all eurymelids and aetalionids, many The two sexes of Cicadelloidea usually re- membracids, and possibly all bitturitids are semble each other in coloration and size. An gregarious, so far as I am aware, no cicadellids exception in respect to color is provided by have this behavior pattern. Since female the sole representative of the Tartessinae to membracids sometimes remain with their occur in New Caledonia. This insect, Calo- eggs after oviposition, some authors, such as tartessus stalii (Signoret), has males that are Haviland (1925), have credited them with ma- largely black and females that are predomi- ternal care. Eurymelids of both sexes have nantly brown. In regard to size, the Stenoco- been recorded as remaining with their eggs tini (Ledrinae) have males that are consider- for a period. It is possible that the gregarious ably smaller than females. habit in this family may be associated with the The Head fact that their nymphs, unlike those of other leafhoppers, lack the ability to jump. The most puzzling feature of the heads of It would seem that all gregarious leafliop- Hemiptera is associated with the origin of pers are ant attended, but the Pogonoscopini, their feeding apparatus. Insects in some other a tribe of the Eurymelidae, are the only ones orders feed by suction, but with all these the that have developed the characteristics of true nature of the transition from mandibulate to myrmecophiles; i.e., they have unusually haustellate mouthparts can be readily under- long legs and small eyes and live in the nests of stood. ants (Evans 1966). Previously, 1 have suggested that, though the ocelli are on the crown in representatives Morphology of the relict subfamily, the Ulopinae, this con- dition is a secondary one. If this is correct, Color and Size even though insects with ventral ocelli do not Previously, 1 have suggested that early seem to be disadvantaged, such a change of leafhoppers were brown, as, for instance, is position would seem to be an adaptive one. Darthula hardwickii , and that green was the Other primitive features of leaffiopper first alternative color to be acquired (Evans heads are the presence of a sensory pit on the 1966). Later evolutionary developments have maxillary plates, which may possibly be given rise to insects that may be predomi- derived from the maxillary palp (Evans 1973), nantly black and have, or lack, yellow, red, or and the complete separation of the maxillary occasionally bluish markings. Some Cicadelli- plates from the genae. dae from Madagascar have striking color pat- Male Genitalia tern differences (Evans 1953). In others, spe- cies occur that have identical male genitalia The male genitalia of insects are more sub- and comprise populations with differing, but ject to change than any other parts of their stable, color patterns (e.g., Eunjmela fenes- bodies. For this reason, they are extensively trata Le Peletier & Serville) (Evans 1933). used for species recognition. The nature and Then, some species have individuals with a the extent of observable differences between very variable color pattern (e.g., Euryme- the aedeagi of closely related insects vary " 1988 EvANS; Leafhopper Biology, Morphology, and Evolution 63 widely and range from slight and constant to nae), and Euacanthella sp. (Euacanthellinae). considerable and variable ones. The subgeni- The best-known examples of the acquisition tal plates and accessory processes are also sub- of morphological features among leaflioppers, ject to considerable change of shape. which are seemingly of nonadaptive signifi- While male genitalia differences are useful cance, are to be found among the Mem- for species separation and genus recognition, bracidae. This phenomenon has been dis- they are