Cicadellids
Source: http://gallery.kunzweb.net/main.php?g2_itemId=10253
HEMIPTERA
Name-Bearing Type: Rhynchota or Hemiptera ( Linnaeus,1758).
Common name: True bugs
Hemiptera, Homoptera, Heteroptera?
There was a long-standing tradition to treat the Homoptera and Heteroptera as separate groups usually having each the rank of order or as suborders within Hemiptera (e.g., Brues et al. 1954; Borror and White 1970; Borror et al. 1981). The former approach was common in North American entomology, in which Hemiptera included Heteroptera only, thus restricting the concept for Hemiptera (Schuh and Slater 1995). Morphological evidence, nonetheless, pointed out that Homoptera was probably paraphyletic (e.g., Goodchild 1966; Schlee 1969d; Bourgoin 1986a, 1986b, 1993; Sweet 1996), or at least that evidence of its monophyly was not documented (Schlee 1969d). Some of the alleged characters supporting “Homoptera” mentioned were: enlarged foramen in the head, large sutures defining the mandibular plate, forewing larger than hindwing, reduced tarsomeres, and simple sperm (Boudreaux 1979; Hamilton 1981). Nonetheless, some of these characters are not synapomorphies (e.g., forewing –hindwing character), or may be based on reductions, which are difficult to homologize (e.g., number of tarsomeres).
Hennig (1969, 1981) doubted the monophyly of Homoptera, stating that the characters used for distinguish it from Heteroptera were symplesiomorphies. He recognized three groups within Hemiptera: Sternorrhyncha, Auchenorrhyncha, and Heteropterodea (as “Heteropteroidea”), the latter clade formed by Coleorrhyncha + Heteroptera (Schlee 1969d). The paraphyly of Homoptera was further corroborated with 18S rDNA sequence analyses (Wheeler et al. 1993; Campbell et al. 1994, 1995; Sorensen et al. 1995; von Dohlen and Moran 1995). Even though evidence is compelling towards a paraphyletic “Homoptera”, and that this has been adequately communica to a more general audience (e.g., Carver et al. 1991; Kristensen 1991; Gullan 2001; Fagua 2005), it is still frequent to see references to “Homoptera” in areas such as Integrated Pest Management (e.g., Pedigo 1996), or in general entomological textbooks (e.g., Arnett 2000), practice that should be avoided (Forero, D. 2008).
“Homoptera” is an abandoned name formely used for all the hemipterans except the Heteroptera. Homopterans are a paraphyletic group, now divided into three monophyletic orders/suborders: Sternorrhyncha (White flies, scale insects, aphids and jumping plant lice), Auchenorrhyncha (Leaf hoppers, plant hoppers, cicadas), and the relict group Coleorrhyncha (Grimaldi, D. & Engel, M. 2005).
Diagnostic features:
(Weber 1930; Hennig 1969, 1981; Cobben 1978; Kristensen 1991)
* The mandibles and maxillary laciniae are modified into concentric stylets, the mandibular enclosing the maxillary ones, both forming the food and salivary channels; the multisegmented sheetlike labium is covering the mandibular and maxillary stylets.
* The maxillary and labial palpi are always absent.
Fig.1 Head and mouthparts of Hemiptera. (A) Head with mouthparts separated; and (B) cross-section of the proboscis. Source: R.E Snodgrass. Principles of insect morphology.
Yoshizawa & Saigusa (2001) proposed another potential synapomorphy:
* The fork of the anterior axillary fold-line of the forewing.
Hemiptera has long been recognized as a monophyletic group (Hennig 1969; Carver et al. 1991). They are very diverse and quite a large order, with over 100,000 species described worldwide. These insects can be very numerous, so they have considerable importance as a food resource, not only in the aquatic environment but even more so in terrestrial environments.
All bugs have piercing - sucking mouthparts. Wing length is variable within and among species, but generally the forewings are smaller than the hindwings. The forewings of some Hemiptera are thickened basally, forming wings called hemelytra (half elytra). Others have membranous forewings and hind wings. A triangular plate called a scutellum may be present at the base of the forewings. Many of these insects are wingless, at least during part of their life cycle.
Bugs are hemimetabolous, lacking a pupal stage (there are a few with unusual development, however). Bugs have several nymphal instars, and although most resemble the adults, in other cases they are quite different in appearance. Bugs are mostly plant feeders, and some induce abnormal growth such as leaf curling or swellings that allow the insects to dwell within a cavity surrounded by plant tissue. Because piercing - sucking mouthparts are conducive to spread of microbial organisms, bugs often transmit plant diseases (Grimaldi, D. & Engel, M. 2005)
Important characteristics for identification of the Hemiptera suborders: (Holzinger, W. 2003)
AUCHENORRHYNCHA (Duméril, 1806)
Diagnostic features:
* Complex tymbal acoustic system.
* Aristate antennal flagellum.
* Reduction of the proximal median plate in the fore-wing base.
Fig.2. A defining feature of the Auchenorrhyncha: the aristate antenna. (a) Cicadidae, (b) Membracidae, and (c) Fulgoridae.
Fulguromorphs has an enlarged pedicel, with numerous sensillar palte organs.
History:
In the middle ages cicadas and spittlebugs remained the only members of the group that received attention and were described in a separate chapter in UlysseAldrovandi´s (1522-1605) main work “De AnimalibusInsectis”. During the 17th century, large tropical or biologically peculiar species were brought from expeditions and attracted interest, such as manna producing species from Ceylon or the 17-year cicada of New England. Only during the first half of the 18th century attention was paid to inconspicuous native species. The classification began with Carl von Linné (Linnaeus) (1707-1778) and his “Systemanaturae…” (10 edition, 1758).Withing the ordenHemiptera, he stablished a single genus, Cicada, and withing the groups “Cruciate” (now Membracidae), “Spumantes” (now Cercopidae) and “Deflexae” (now Cicadellidae). Following Linné’s principles of systematics, the activities of observation, comparison and classification increased at the end of the 18th century, resulting in a growing number of species descriptions of Auchenorrhyncha. (Holzinger, W. 2003).
Auchenorrhyncha has been traditionally divided in two main groups:
(Carver et al. 1991)
* Cicadomorpha
* Fulguromorpha
Nonetheless, it has been extensively debated if Auchenorrhyncha is a monophyletic group or not.
CICADOMORPHA (Evans, 1946)
Sources: Holzinger, W. (2003); Forero, D. (2008)
Withing this group, three superfamilies are recognized:
1. Cercopoidea (spittlebugs or froghoppers)
Fig. 3. Left: Sphenorhina melanoptera. Right: Prosapia bicincta.
2. Cicadoidea
Fig.5. Above (right): Cladonota sp. (Membracidae). Panama; Above (Left): Proconia sp. (Cicadellidae). Ecuador; Below (left): Ferrariana trivittata (Cicadellidae). Panama; Below (right): Platygonia spatulata (Cicadellidae). Panamá.
CICADELLIDAE (Leafhoppers) (Latreille,1825)
Source: Forero, D. (2008); Triplehorn, Charles A. and Norman F. Johnson. (2005).
The speciose family Cicadellidae, commonly called leafhoppers and sharpshooters (Membracoidea), has more than 22.000 described species worldwide and 5.000 species in the Neotropical region (Freytag and Sharkey 2002). Cicadellidae has about 36 subfamilies worldwide (Oman et al. 1990; Dietrich 2004).
They constitude a very large group, and they are of various forms, colors and sizes. They are similar to froghoppers and aetalionids in the genus Aetalion, but they have one or more rows of small spines extending the lenght of the hind tibiae. Leafhoppers rarely exceed the 13mm long, and many are only a few milimeters long. Many are marked with a beautifull color pattern.
Habitat
Leafhoppers live on almost all types of plants, including forest, shade and orchard trees, shrubs, grasses, and many field and garden crops. They feed principally on the leaves of their food plant. The food in most species is quit specific, and the habitat is therefore well defined.
Life cycle
Most leafhoppers have a single generation a year, but a few have two or three. The winter is usually passed in either the adult or the egg stage, depending of the species.
Economically important pests
They caused five major types of injury to plants:
1. Some species remove excesive amount of sap and reduced or destroy the chlorophyll in the leaves, causing the leaves to become covered with minute white or yellow spots. With continued feeding, the leaves turned yellowish or brownish.
Injury produced on apple leaves by various species of Erythroneura, Typhlocyba, and Empoasca.
2. Some species interfere with the normal physiology of the plant, for example by the mechanically plugging the phloem and the xylem vessels in the leaves so that transport of food materials is impaired. A browning of the outer portion of the leave, and eventually of the entired leave, results.
Injury produced by potato leafhopper, Empoasca fabae.
3. A few species injured plants by ovipositing in green twigs, often causing the terminal portion of the wings to die.
Various species of Gyponana cause damage of this sort. The eggs punctures are similar tp those of the buffalo treehopper, but smaller.
4. Many species of Cicadellids act as vectors of organisms that caused plant diseases. Astern yellows, corn stunt, phloem necrosis of Elm, Pierce's disease of grape, phony peach, potato yellow dwarf, curly top in sugar beets, and other plant diseases are transmitted by leafhoppers.
Chiefly species in the subfamilies Agalliinae, Cicadellinae, and Deltocephalinae.
5. Some species cause stunting and leaf curling that result from the inhibition of growth on the undersurface of the leaves, where the leafhoppers feed.
The potato Leafhopper, Empoasca fabae also produceds this kind of injury.
Many species of leafhoppers emit fron the anus a liquid called "honeydew". It consists of unused portions of plant sap to wich are added certain waste products of the insects.
Related article: Steiner, F. et al. 2004. A novel relationship between ants and leafhopper. (Hymenoptera: Formicidae; Hemiptera: Cicadellidae). European Journal of Entomology; 2004; 101, 4; ProQuest pg. 689.
Phylogeny
Source: Forero, D. (2008)
Dietrich and Deitz (1993) analyzed the relationships of the Membracoidea using morphological characters, focusing mostly in non-cicadellid taxa (Aetalionidae and Membracidae). In their analysis Cicadellidae is monophyletic and the sister group of (Melizoderidae + (Aetalionidae + Membracidae)).
- Synapomorphies for Cicadellidae: According to Dietrich and Deitz (1993).
- Mesonotum exposed posteriorly.
- Labium not reaching the metathoracic coxae.
- m-cu1 crossvein present.
- Metatibia with distinct long setae.
- Tarsomere I of hind leg without cucullate setae.
- Sternum IX and subgenital plate not fused.
- Abdominal tergum with divided acanthae.
All of which are homoplastic characters in their analysis. Hamilton (1999) presented a phylogeny of the extinct and extant families of Membracoidea, and placed Myerslopiidae as the sister group of the remaining families. In Dietrich et al. (2001) analysis Myerslopiidae grouped with Cicadoidea taxa, whereas in Cryan’s (2005) Myerslopiidae was recovered as the sister group to all remaining Membracoidea. Hamilton (1999) also considered Ulopidae as a separate group from Cicadellidae, and placed Cicadellidae as sister group of (Ulopidae + (Aetalionidae + Membracidae)), rendering Cicadellidae paraphyletic with respect to Membracidae. This scheme was first supported by Dietrich et al. (2001b) based on the analysis of 28S rDNA sequences, where the clade including Ulopinae and Megophthalminae appears as more closely related to Aetalionidae + Membracidae; and posteriorly by Cryan (2005).
Phylogenetic hypotheses based on morphology were first proposed by Ross (1957), then by Hamilton (1983) and Dietrich (1999). Dietrich et al. (2001) was the first attempt to recover the phylogeny of most cicadellid subfamilies and tribes using 28S rDNA sequences, and found that most of them were not monophyletic. Within Cicadellidae some groups had been subject of analyses (e.g., Evacanthinae: Dietrich 2004; Cicadellinae: Takiya et al. 2006; Deltocephalinae: Zahniser and Dietrich 2008).
- According to C. H. Dietrich et al. 2001
Traditionally, Cicadellidae have been regarded as the sister group of a lineage comprising the three treehopper families (e.g., Strümpel, 1972; Evans, 1977), and a recent morphology-based cladistic analysis provided some support for this relationship (Dietrich and Deitz, 1993). However, some authors, based on morphological (Hamilton, 1983, 1999), paleontological (Shcherbakov, 1992), and behavioral (Rakitov, 1998) evidence, have suggested that the Cicadellidae are paraphyletic with respect to Membracidae. These alternative phylogenetic hypotheses (Fig. 6a), which persist at least partly because of ambiguities in the available morphological evidence (cf. Dietrich and Deitz, 1993; Hamilton, 1983, 1999), have yielded con flicting classifications of membracoid family-group taxa (cf. Hamilton, 1983; Oman et al., 1990) and require different interpretations of the evolutionary origins of various membracoid behavioral, ecological, and physiological traits.
For example, treehoppers, like cicadas and spittlebugs, have sessile nymphs that cannot jump. Nymphs of many treehopper species also form aggregations that are tended by ants (Wood, 1993).
In contrast, leafhopper nymphs (with few exceptions) are active and capable of jumping and are rarely ant-attended.
Leafhoppers are also unique among Cicadomorpha in producing brochosomes—minute, hydrophobic granules produced in the Malpighian tubules and applied to the external surfaces of the body in an act known as anointing (Rakitov, 1996, 1999).
If treehoppers are derived from leafhoppers (Fig. 6b), then their derivation presumably coincided with losses of brochosome production and nymphal jumping ability. If treehoppers and leafhoppers are sister groups (Fig. 6a), then treehoppers may merely retain the ancestral condition of these traits found in cicadas and spittlebugs.
Conflicting interpretations of the fossil record and present patterns of geographic distribution are also required by the alternative membracoid phylogenies. Cicadellidae first appear in the fossil record in the lower Cretaceous (Hamilton, 1990, 1992), whereas treehoppers are unknown in fossil material older than Tertiary age (Shcherbakov, 1996), suggesting that leafhoppers arose much earlier than treehoppers.
Both groups also occur worldwide, but 11 of the 13 treehopper subfamilies are restricted to the New World and the 3 most plesiomorphic membracid subfamilies are presently restricted to the Neotropics (Dietrich and Deitz, 1993). If leafhoppers and treehoppers are sister groups, then the absence of pre-Tertiary treehopper fossils is a sampling artifact. If leafhoppers gave rise to treehoppers, then treehoppers presumably originated in the New World after the breakup of Gondwana and reached the Old World by dispersal.
TO BE CONTINUED...
Structure of leafhoppers:
Fig. 7.Paraphlepsius irroratus (Cicadellidae). A, Dorsal view; B, anterior view of head. Ant, antennae; ap, appendix; clp, clypeus; e, compound eye; el, elytron of front wing; fm, femur; fr, frons; ge, gena; lbr, labrum; lo, lorum; mv, marginal vein; n1, pronotum; oc, ocelli; scl2, mesoscutellum; tb, tibia; ver, vertex.
Termonology comparison of wing veins:
Fig. 8. A.Face of Xerophloea viridis (Ledrinae); B, face of Paraphlepsius irroratus (Deltocephalinae); C, face of Idiocerus alternatus (Idioceranidae); D, face of Tinobregmus vittatus (Coelidiinae); E, face of Sibovia occatoria (Cicadellinae); F. front wing of Kunzeana marginella (Typhlocybinae); G, face of Parabolocratus (Hecalinae); H, front wing of Endria inimical (Deltocephalinae); I, hind wing of Macropsis viridis (Macropsinae); J, head, pronotum, and scutellum of Dorycephlus platyrhynchus, dorsal view (Dorycephalinae); K, same, lateral view; L, head, pronotum, and scutellum of Xerophloea viridis, dorsal view (Ledrinae); M, hind wing of Aceratagallia sanguinolenta (Agalliinae). ant. Antennae; AP, apical cells; clp clypeus; clpl, Clypellus; eps1 episternum of prothorax; ge, gena; oc, ocellus.
Fig 9. A-F, head anterior view: A, Evacanthus (Evacanthini); B, Krisna (Krisnini); C, Tartessus (Tartessinae); D, Platyproctus (Adelungiini); E, Bathysmatophorus (Errhomanini); F, Thymbrus (Thymbrini). G-H, head and prothorax, lateral view: G, Cicadalla (Cicadelini); H, Matsumurella (Athysanini). I-K, head pronotum, mesonotum and scutellum, dorsal view: I, Populicerus (Idiocerinae); J, Pediopsoides (Macropsinae); Oniella (Evachanthini). Drawing A-F original; G-K from Anufriev & Emeljanov (1988).
Fig.10. Leafhopper wings. A-G, forewing: A, Hortensia (Cicadellini); B, Erromus (Errhomenini); C, Deltocephalus (Deltocephalini); D Hamana (Scarini); E, Idiocerus (Idiocerinae); F, Typhlocyba (Typhlocybini); G, Jikradia (Coelidiinae). H-O, hind wing: H, Agallia (Agalliini); I, Macropsis (Macropsinae); J, Penestragania (Iassini); K, Typhlocyba (Typhlocybini); L, Protalebrella (Alebrini); M, Hymetta (Erythroneurini); N, Empoasca (Empoascini); O, Joruma (Jorumini). Drawings from Oman (1949).
Leafhopper leg morphology:
Fig.11. A-E, apex of hind femur, dorsal view, showing variation in macrosetal formula: A, 2+2+1; B, 2+2+1; C, 2+1+1; D, 2+1. F-J, right hind tibia, posterior view, except G and J, cross-section: F-G, Bathysmatophorus (Errhomenini); H, Bothrogonia (Cicadellini); I-J, Diplocolenus (Paralimnini). K-N, left front femur, anterior view: K, Doratura (Doraturini); L, Thagria (Thagriini); M, Alebra (Alebrini); N, Xestocephalus (Xestocephalini). O-P, hind tarsus, ventral view: O, Kybos (Empoascini); P, Balclutha (Balclutini).
BIBLIOGRAPHY
Costa, J. 2006. The Other Insect Societies. Library of congress cataloging-in publication data. Pag.245.
Dietrich, C. H., Rakitov, R. A., Holmes, J. L. & Black, W. C. 2001.Phylogeny of the Major Lineages of Membracoidea (Insecta: Hemiptera: Cicadomorpha) Based on 28S rDNA Sequences Molecular Phylogenetics and Evolution. Vol. 18, No. 2, February, pp. 293–305.
Forero, D. (2008). The Sistematics of the Hemiptera. Revista Colombiana de Entomología 34 (1): 1-21
