| Treehopper | |
|---|---|
_Stictocephala_bisonia.jpg) | |
| Stictocephala bisonia | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hemiptera |
| Suborder: | Auchenorrhyncha |
| Infraorder: | Cicadomorpha |
| Superfamily: | Membracoidea |
| Family: | Membracidae Rafinesque, 1815 |
| Subfamilies | |
Centronodinae(disputed) | |
| Synonyms | |
Nicomiidae | |
Treehoppers (more preciselytypical treehoppers to distinguish them from theAetalionidae) andthorn bugs are members of thefamilyMembracidae, a group ofinsects related to thecicadas and theleafhoppers. About 3,200species of treehoppers in over 400genera are known.[1] They are found on all continents except Antarctica; only five species are known fromEurope.[2] Individual treehoppers usually live for only a few months.
Treehoppers, due to their unusual appearance, have long interestednaturalists. They are best known for their enlarged and ornatepronotum, expanded into often fantastic shapes that enhance theircamouflage ormimicry, often resemblingplant thorns (thus the commonly used name of "thorn bugs" for a number of treehopper species). Treehoppers have specialized muscles in the hind femora that unfurl to generate sufficient force to jump.[3]
It had been suggested that the pronotal "helmet" could beserial homologues of insect wings,[4] but this interpretation has been refuted by several later studies, such as Mikó et al. (2012) and Yoshizawa (2012).[5][6]
Treehopper nymphs can be recognised by the tube-like ninth abdominal segment, through which the tenth and eleventh segments can be exerted in defence or to providehoneydew to other animals (explained further in the next section). The tube is longer (compared to the rest of the body) in earlyinstars compared to late instars.[7]
Treehoppers have pointy, tube-shapedmouthparts that they use to pierce plant stems and feed upon sap. The young can frequently be found on herbaceous shrubs and grasses, while the adults more often frequent hardwood tree species. Excess sap becomes concentrated ashoneydew, which often attractsants. Some species have a well-developed antmutualism, and these species are normally gregarious as well, which attracts more ants. The ants provide protection frompredators. Treehoppers mimic thorns to prevent predators from spotting them.[8]
Others have formed mutualisms with wasps, such asParachartergus apicalis.[9] Evengeckos form mutualistic relations with treehoppers, with whom they communicate by small vibrations of the abdomen.[10]
Mutualisms are not done only for protection against predators. Nymphs of the treehopperPublilia concava have higher survivorship in the presence of ants even when predators are absent. This is suspected to be because uncollected honeydew leads to the growth ofsooty mould, which may hinder excretion by treehoppers andphotosynthesis by their host plants. Ant collection of honeydew thus allows treehoppers to feed more (the feeding facilitation hypothesis).[11]
Eggs are laid by the female with her saw-likeovipositor in slits cut into thecambium or live tissue of stems, though some species lay eggs on top of leaves or stems. The eggs may beparasitised bywasps, such as the tinyfairyflies (Mymaridae) andTrichogrammatidae. The females of some membracid species sit over their eggs to protect them from predators and parasites, and may buzz their wings at intruders. The females of some gregarious species work together to protect each other's eggs. In at least one species,Publilia modesta, mothers serve to attract ants whennymphs are too small to produce much honeydew. Some other species make feeding slits for the nymphs.[12]
Most species are innocuous to humans, although a few are considered minor pests, such asUmbonia crassicornis (a thorn bug), the three-cornered alfalfa hopper (Spissistilus festinus), and thebuffalo treehopper (Stictocephala bisonia), which has been introduced toEurope. The cowbugOxyrachis tarandus has been recorded as a pest ofWithania somnifera in India.[13]
The diversity of treehoppers has been little researched, and theirsystematic arrangement is tentative. It seems three main lineages can be distinguished; theEndoiastinae are the most ancient treehoppers, still somewhat resemblingcicadas.Centrotinae form the second group; they are somewhat more advanced but the pronotum still does not cover thescutellum in almost all of these. TheDarninae,Heteronotinae,Membracinae andSmiliinae contain the mostapomorphic treehoppers.[citation needed]
Several proposedsubfamilies seem to beparaphyletic.Centronodinae andNicomiinae might need to be merged into the Centrotinae to result in amonophyletic group.
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Authority control databases: National |
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