Ask the Expert:Chris Dietrich
Treehoppers (Hemiptera:Cicadomorpha: Membracoidea)
Treehoppers are a diverse group of plant-feeding insects comprising approximately 3,200 species worldwide. Currently, these species are placed in three separate families (Melizoderidae, Aetalionidae, and Membracidae), of which Membracidae is by far the largest and most widespread. Most membracids may be easily distinguished from related Hemiptera by their enlarged and often highly ornate pronotum (the dorsal part of the first thoracic segment). These insects have long attracted attention because of their bizarre forms and unusual behaviors. Many species are gregarious, forming large and often conspicuous groups of adults and immatures. Some of these are ant-mutualistic and may also exhibit presocial behavior. Most species are solitary and these are often cryptic, at least as immatures. True to their name, treehoppers are most abundant in forest or savanna habitats, particularly in the tropics, where they utilize a wide variety of tree species as host plants. Nevertheless, many species feed on herbaceous host plants, at least for part of their life cycle.
Treehopper Photos(by C.H.Dietrich).
- an aggregation of adults and nymphs (immatures) of Adippe histrio from Ecuador--the conspicuous coloration of these insects may be an indication that they are distasteful to predators;
- a newly emerged adult Heteronotus sp. from Ecuador (upper right) with its nymphal skin (lower left)--the enlarged pronotum of the adult bears five sharp spines that may deter predators;
- an adult Stictopelta sp. from southern Mexico--the pronotum almost completely conceals the rest of the body;
- Smilia fasciata, a common eastern North American species, feeding on an oak (Quercus sp.) twig;
- a memberof the Enchenopa binotata species complex feeding on redbud (Cercis canadensis);
- Archasia belfragei, another common North American oak-feeding species;
- a female Aetalion sp. (Aetalionidae) guarding her egg mass;
- a female Scytodepsa sp. from Guyana, a member of the most primitive group of Membracidae, guarding her eggs;
- Tolania sp. from Ecuador--species in this group, in which the pronotum does not extend backward over the rest of the body, apparently arose from ancestors that had an enlarged pronotum.