Treehoppers (more precisely typical treehoppers to distinguish them from the Aetalionidae) and thorn bugs are members of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Membracidae, a group of

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs ...

s related to the

cicada The cicadas () are a superfamily, the Cicadoidea, of insects in the order Hemiptera (true bugs). They are in the suborder Auchenorrhyncha, along with smaller jumping bugs such as leafhoppers and froghoppers. The superfamily is divided into two ...

s and the

leafhopper A leafhopper is the common name for any species from the family Cicadellidae. These minute insects, colloquially known as hoppers, are plant feeders that suck plant sap from grass, shrubs, or trees. Their hind legs are modified for jumping, and ...

s. About 3,200

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of treehoppers in over 400

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial ...

are known.Treehoppers.
Dr. Metcalf. NCSU Libraries. North Carolina State University. They are found on all continents except Antarctica; only five species are known from

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

. Individual treehoppers usually live for only a few months.

Morphology

Treehoppers, due to their unusual appearance, have long interested naturalists. They are best known for their enlarged and ornate

pronotum The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum ( dorsal), the prosternum ( ventral), and the propleuron ( lateral) o ...

, expanded into often fantastic shapes that enhance their

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...

mimicry In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. Often, mimicry ...

, often resembling plant thorns (thus the commonly used name of "thorn bugs" for a number of treehopper species). The specialised pronotum (or helmet) may not be simply an expansion of the prothoracic sclerite, but a fused pair of dorsal appendages of the first thoracic segment. The treehopper has specialized muscles in its hind femora that unfurl to generate sufficient force to jump. These may be serial homologues of insect wings, which are dorsal appendages of the second and/or third thoracic segments, although this interpretation has been seriously challenged. Evidence for this theory included the development of the helmet, which arises as a pair of appendages attached to each side of the dorsal prothorax by an articulation with muscles and a flexible membrane that allow it to be mobile (also, similar

gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

s are involved in development of the helmet and the wings). Distinguishing males from females is accomplished only by looking at the genitalia.

Ecology

Treehoppers pierce plant stems with their beaks 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 as honeydew, which often attracts ants. Some species have a well-developed ant mutualism, and these species are normally gregarious as well, which attracts more ants. The ants provide protection from

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...

s. Treehoppers mimic thorns to prevent predators from spotting them. Others have formed mutualisms with wasps, such as '' Parachartergus apicalis''. Even

gecko Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from . Geckos ar ...

s form mutualistic relations with treehoppers, with whom they communicate by small vibrations of the abdomen. Eggs are laid by the female with her saw-like

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typica ...

in slits cut into the

cambium A cambium (plural cambia or cambiums), in plants, is a tissue layer that provides partially undifferentiated cells for plant growth. It is found in the area between xylem and phloem. A cambium can also be defined as a cellular plant tissue from ...

or live tissue of stems, though some species lay eggs on top of leaves or stems. The eggs may be parasitised by

wasp A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder. Th ...

s, such as the tiny fairyflies (Mymaridae) and

Trichogrammatidae The Trichogrammatidae are a family of tiny wasps in the Chalcidoidea Chalcid wasps (, , for their metallic colour) are insects within the superfamily Chalcidoidea, part of the order Hymenoptera. The superfamily contains some 22,500 known ...

. 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 The gens Publilia (), sometimes written Poblilia, was a plebeian family at ancient Rome. Members of this gens are first mentioned in the early decades of the Republic. The ''lex Publilia'' passed by Volero Publilius, tribune of the plebs in 47 ...

'', mothers serve to attract ants when

nymph A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are ty ...

s are too small to produce much honeydew. Some other species make feeding slits for the nymphs. Like the adults, the nymphs also feed upon sap, and unlike adults, have an extensible anal tube that appears designed to deposit honeydew away from their bodies. The tube appears to be longer in solitary species rarely attended by ants. It is important for sap-feeding bugs to dispose of honeydew, as otherwise it can become infected with

sooty mould Sooty mold (also spelled sooty mould) is a collective term for different Ascomycete fungi, which includes many genera, commonly '' Cladosporium'' and '' Alternaria''. It grows on plants and their fruit, but also environmental objects, like fences ...

s. Indeed, one of the evident benefits of ants for ''

Publilia concava The gens Publilia (), sometimes written Poblilia, was a plebeian family at ancient Rome. Members of this gens are first mentioned in the early decades of the Republic. The ''lex Publilia'' passed by Volero Publilius, tribune of the plebs in 47 ...

'' nymphs is that the ants remove the honeydew and reduce such fungal growth. Most species are innocuous to humans, although a few are considered minor pests, such as ''

Umbonia crassicornis ''Umbonia crassicornis'', commonly known as the thorn bug, is a widespread member of the insect family Membracidae, and an occasional pest of ornamentals and fruit trees in southern Florida. The body length of the adult is approximately . This i ...

'' (a thorn bug), the three-cornered alfalfa hopper ('' Spissistilus festinus''), and the

buffalo treehopper The buffalo treehopper (''Stictocephala bisonia'') is a species of treehopper belonging to the subfamily Membracinae. It is sometimes classified as ''Ceresa bisonia''. Distribution This species is native to North America, but now it is widespr ...

(''Stictocephala bisonia''), which has been introduced to

. The cowbug '' Oxyrachis tarandus'' has been recorded as a pest of '' Withania somnifera'' in India.

Systematics

The diversity of treehoppers has been little researched, and their

systematic Systematic may refer to: Science * Short for systematic error * Systematic fault * Systematic bias, errors that are not determined by chance but are introduced by an inaccuracy (involving either the observation or measurement process) inheren ...

arrangement is tentative. It seems three main lineages can be distinguished; the Endoiastinae are the most ancient treehoppers, still somewhat resembling

s. Centrotinae form the second group; they are somewhat more advanced but the pronotum still does not cover the scutellum in almost all of these. The Darninae, Heteronotinae, Membracinae and Smiliinae contain the most

apomorph In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to hav ...

ic treehoppers. Several proposed

subfamilies In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

seem to be

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

. Centronodinae and Nicomiinae might need to be merged into the Centrotinae to result in a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic ...

group. Treehopper.jpg,

Adults An adult is a human or other animal that has reached full growth. In human context, the term ''adult'' has meanings associated with social and legal concepts. In contrast to a "minor", a legal adult is a person who has attained the age of majori ...

and

nymphs A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are ty ...

of '' Umbonia'' in