Derbidae | |
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Otiocerus abbotii | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hemiptera |
Suborder: | Auchenorrhyncha |
Infraorder: | Fulgoromorpha |
Superfamily: | Fulgoroidea |
Family: | Derbidae Spinola, 1839 [1] [2] |
Subfamilies [2] | |
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The family Derbidae (commonly called derbids) is a large and diverse group of planthoppers (Fulgoroidea, Hemiptera), widely distributed in the tropics and also found in subtropical and temperate regions. It includes more than 150 genera and more than 1500 species. [2] The adults suck the sap of plants while the nymphs live mainly in decaying organic matter, for example under the bark of dead tree trunks, feeding on fungi. In some groups of species the general structure of the insects is largely uniform, whereas in others like in the subfamily Otiocerinae various forms can be found. For example, the shape of the head, the antennae or the wings can differ considerably among genera and species. [3] [4] [5]
Derbids are typically 5–10 mm long from head to the end of the forewings. [5] [6] [7] They can be distinguished from other planthopper families by a combination of different characters, the most important one being the very short terminal segment of the rostrum which is often only as long as wide. [4] [7] The illustration of Eocenchrea maorica on this page highlights the short terminal segment and also shows the general appearance of a derbid which is found in a number of tribes. The species in this example is from the tribe Cenchreini, subfamily Derbinae. In this form, the length of the body from head to tip of the abdomen is slightly more than half the length from head to tip of the forewings. The end of the wings and the profile of the head are uniformly rounded, the wings are held in a roof-like (tectiform) position when the insect is at rest and the antennae are small and inconspicuous. [7] [3]
Various other forms can be found among the Derbidae, especially in the shape and length of the wings, how these are held at rest, as well as the structure of the head and the antennae. These less common features may be important for placing a derbid in the respective subfamily and tribe. For example, the forewings may be extremely long and narrow while the hindwings are very small (tribe Zoraidini). The wings may be also spread out widely when the insects are at rest. The head may be extended and extremely compressed in frontal view with the anterior part consisting of two thin, leaf-like blades. The antennae may be long and branched. [4] [7] [3] Derbidae might also have striking colors and wing pattern. [8] [9] Some of these different forms, colors and wing pattern are illustrated in the gallery below.
Information on the biology of the Derbidae is scarce. They clearly belong to the planthoppers which by nature feed by sucking the sap of plants and they have the corresponding mouthparts. However, relatively little is known about their life cycle, their feeding habits and their host plants. Monocots, especially palm trees, are often the preferred hosts. [10] [11] Still, the adults are often described as "gathering" or "resting" on the plants. The nymphal stages have been found associated with decaying organic matter like decaying tree trunks. For example, they have been found under the bark of dead trees or in heaps of palm debris, where they feed on fungi. [12] [3] In contrast, the nymphs of Cedusa hedusa were collected from mats of the moss Polytrichum commune in southern North America, where they were feeding either on fungi associated with the moss, or on the moss itself. [13]
Several derbids are suspected of transmitting phytoplasma diseases of palms. However, no clear evidence for such transmission has been reported so far. In Mozambique, Diostrombus mkurangai (tribe Zoraidini) was one of the most common sap-sucking insects on coconut palms affected by the lethal yellowing disease and the causal phytoplasma agent was present in this derbid. [14] In Ghana, a similar disease called Cape Saint Paul Wilt also affects coconut palms and derbids from the genera Diostrombus and Patara were again common on diseased palms. In a transmission trial, derbids were collected from diseased palms and placed in cages together with healthy palms. One of two coconut palms exposed to 4,380 Diostrombus derbids tested positive for the disease with PCR, but failed to develop symptoms. [15] In Jamaica, 13 out of 43 derbids from the genus Cedusa (tribe Cedusini) collected from coconut palms in an area affected by the coconut lethal yellowing disease contained a phytoplasma similar to the causal agent of that disease. [16] In Florida, Omolicna joi (tribe Cenchreini) was one of three species of planthoppers common on sabal palms affected by the phytoplasma disease Texas Phoenix Palm Decline. [17]
Most studies on Derbidae have dealt with their taxonomy. The family is morphologically most similar to the sister family Achilidae and some genera have features matching both families. For example, the genus Breddiniola has been traditionally assigned to the family Achilidae, but is now placed in the family Derbidae. [18] The classification of the different subgroups of the Derbidae (subfamilies and tribes) has also changed repeatedly over the years. [19] [20] [2]
While there seems to be no disagreement among authors on the classification of the different planthopper families, there are few DNA analyses which could confirm the taxonomy of the planthoppers, as well as clarify the phyllogenetics within the Derbidae. A study from 2005 has analysed the DNA of 53 planthopper species (including 5 derbids) from 15 families. It confirmed the close relationship between the Derbidae and the Achilidae and also revealed a close relationship between the Derbidae and the Tropiduchidae. [21]
As of 2024, 1722 species of Derbidae in 166 genera have been described world-wide. [2] However, judging from images published on the internet, many species remain undescribed. [22] In a revision of the tribe Rhotanini in 2011, 294 species were listed and more than half of them (178) were described as new. [9]
The genera of Derbidae are assigned to the following 3 subfamilies and 22 tribes: [2]
Lethal yellowing (LY) is a phytoplasma disease that attacks many species of palms, including some commercially important species, such as the coconut and date palm. In the Caribbean, it is spread by the planthopper Haplaxius crudus which is native to Florida, parts of the Caribbean, parts of Australia and Central America. The only effective cure is prevention, e.g., planting resistant varieties of coconut palm and preventing a park-like or golf-course-like environment which attracts the planthopper. Some cultivars, such as the Jamaica Tall coconut cultivar, nearly died out because of lethal yellowing. Heavy turf grasses and similar green ground cover attracts the planthopper to lay its eggs there, and the nymphs develop at the roots of these grasses. The planthoppers' eggs and nymphs can pose a great threat to coconut-growing countries' economies, especially ones into which grass seeds for golf courses and lawns are imported from the Americas.
The family Fulgoridae is a large group of hemipteran insects, especially abundant and diverse in the tropics, containing over 125 genera worldwide. They are mostly of moderate to large size, many with a superficial resemblance to Lepidoptera due to their brilliant and varied coloration. Various genera and species are sometimes referred to as lanternflies or lanthorn flies, though they do not emit light.
A planthopper is any insect in the infraorder Fulgoromorpha, in the suborder Auchenorrhyncha, a group exceeding 12,500 described species worldwide. The name comes from their remarkable resemblance to leaves and other plants of their environment and that they often "hop" for quick transportation in a similar way to that of grasshoppers. However, planthoppers generally walk very slowly. Distributed worldwide, all members of this group are plant-feeders, though few are considered pests. The infraorder contains 2 superfamily, Fulgoroidea and Delphacoidea. Fulgoroids are most reliably distinguished from the other Auchenorrhyncha by two features; the bifurcate (Y-shaped) anal vein in the forewing, and the thickened, three-segmented antennae, with a generally round or egg-shaped second segment (pedicel) that bears a fine filamentous arista.
The Cixiidae are a family of fulgoroid insects, one of many families commonly known as planthoppers, distributed worldwide and comprising more than 2,000 species from over 150 genera.
Dictyopharidae is a family of planthoppers, related to the Fulgoridae. The family comprises nearly 760 species in more than 150 genera which are grouped into two subfamilies, Dictyopharinae and Orgeriinae.
Issidae is a family of planthoppers described by Spinola in 1839, belonging to the order Hemiptera, suborder Auchenorrhyncha superfamily Fulgoroidea.
Nogodinidae is a family of planthoppers. They have membranous wings with delicate venation and can be confused with members of other Fulgoroid families such as the Issidae and Tropiduchidae. Some authors treat it as a subfamily of the Issidae.
Cixiinae is a planthopper subfamily in the family Cixiidae. It is one of three such subfamilies, the other two being the Bothriocerinae and the Borystheninae. While a few species had been tested in a larger study of the Fulgoroidea, neither the Cixiinae nor its tribes were analysed cladistically until 2002. Resolution of tribal relationships is incomplete and additional testing of the tribes with samples larger than one per tribe is needed.
Haplaxius crudus is a planthopper species in the genus Haplaxius.
Lophopidae is a family of fulgoroid plant-hoppers with most species found in tropical South America and Asia.
Kinnaridae is a family of fulgoroid planthoppers. This is a small family with a little more than 20 genera and about a 100 species. The family was erected by Muir in 1925 and most members are found in the Oriental and Neotropical regions and only a few in the Nearctic and Palaearctic regions.
Delphacinae is a subfamily of delphacid planthoppers in the family Delphacidae. There are at least 1,700 described species in Delphacinae.
Melanoliarus is a genus of cixiid planthoppers in the family Cixiidae. There are at about 50 described species in Melanoliarus, which are common and widespread in the Nearctic and Neotropics.
Achilidae is a family of planthoppers, sometimes called "achilids" in the order Hemiptera. There are at least 520 described species in Achilidae.
Otiocerinae is a subfamily of derbid planthoppers in the family Derbidae. There are about 7 genera and more than 90 described species in Otiocerinae.
Cenchreini is a tribe of derbid planthoppers in the family Derbidae. There are at least 30 genera in Cenchreini.
Derbinae is a subfamily of derbid planthoppers in the family Derbidae.
Dictyopharinae is a subfamily of dictyopharid planthoppers in the family Dictyopharidae. There more than 100 genera and 500 described species in Dictyopharinae.
The Gengidae are a family of Fulgoromorpha (planthoppers), with species found in South Africa.
The Achilixiidae are a family of Fulgoromorpha (planthoppers); species may be found in the neotropical and Asian regions. They are closely related to Achilidae and are sometimes included under Achilidae as a subfamily. Like Achilidae, species generally feed on several species of plant though the nymph stage has been found to feed on fungus. Like other planthoppers, the immature stage is covered in a wax which may help protect it from predators. Achilixiidae are small or medium sized for planthoppers and are greatly compressed, not depressed like the Achilidae.