Fovealvus nama, Gnezdilov, Vladimir M. & Wilson, Michael R., 2007

Gnezdilov, Vladimir M. & Wilson, Michael R., 2007, A new genus and a new species of the tribe Mithymnini (Hemiptera: Fulgoromorpha: Nogodinidae) from Namibia, with sternal sensory pits in the adult, Zootaxa 1453, pp. 55-62 : 59-61

Fovealvus nama sp. nov.

(figs 1–3)

Description. Body length. Males – 3.1–3.5 mm. Females – 3.6–3.7 mm.

General coloration of upper side dark brown. Metope with a pair of light-yellow spots medially and lightyellow transverse stripe near clypeus. Frontal part of clypeus brown yellowish, with dark brown transverse stripes, lateral sides of clypeus dark brown. Genae under eyes and ocelli light-yellow. Pronotum dark brown yellowish. Scutellum dark brown with light-yellow median and lateral keels. Fore wing with light-yellow spots of different size. Hind wing opaque. Fore and middle legs dark brown, hind legs brown yellowish. Apices of teeth and socle setae black. Abdominal tergites brown, sternites brown proximally and light-yellow or whitish distally. Male genital segments brown yellowish. Gonoplacs brown with light-yellow whitish spots. Female anal tube brown. Gonocoxa VIII with black caudo-dorsal angle.

Material. Holotype, Male: SW Africa [ Namibia], Aus, 8–30.XI.1929, R.E. Turner leg. ( BMNH). Paratypes ( BMNH and ZIN): 10 males, 3 females, as holotype; 2 males, 2 females, same locality, XII.1929; 1 male, same locality, I.1930, all leg. R.E. Turner.

Etymology. The species name is derived from the African ethnic group “ Nama ”.

Discussion

In the modern Hemiptera literature there are two terms used for special receptive hairs of the body – “trichobothria” and “sensory pit”. The first one is more commonly used by heteropterists, but the second one by specialists of Auchenorrhyncha. The term trichobothria was proposed by Dahl for “a very long slender seta, set in a cup-like depression in the cuticle or on a small dome”; “the trichobothria is usually longer than the surrounding setae and oriented at more or less right angle to the cuticle, whereas most setae form an acute angle with the surrounding body surface” ( Schuh 1975). A sensory pit is defined as “a small hole with horizontal seta directed inwards and diverging from its border; the length of the seta is not greater than diameter of the hole” ( Emeljanov 2001). Trichobothria are commonly found in the adults of Heteroptera, but sensory pits are probably absent in the group. In Auchenorrhyncha sensory pits are specific organs in fulgoroid larvae and are very rare in adults ( Emeljanov 2001); but trichobothria also present in both. Fovealvus gen. nov. and Alleloplasis Waterhouse, 1839 ( Tropiduchidae sensu Gnezdilov 2007 ) have trichobothria and sensory pits on abdominal sternites (figs 4–10). Both structures probably are used as mechanoreceptors or receptors of atmospheric humidity ( Schuh 1975; Holzinger et al. 2002). Sweet (1996) suggested that presence of trichobothria is an autapomorphy of Fulgoromorpha+Coleorrhyncha+Heteroptera. According to Emeljanov (2001) sensory pits are strictly of tergal nature. Until now in the Fulgoromorpha sensory pits on abdominal sternites were known only in the genus Alleloplasis . Two described species of the genus – A. darwini Waterhouse, 1839 and A. vespula Fennah, 1949 differ from each other in number of pits ( Fennah 1949). In Fovealvus gen. nov. the male and female have 6 pairs of sensory pits on hind margin of 6th abdominal sternite (figs 4, 5) and the female also has a couple of pits at the middle of 7th sternite (figs 6, 7). Apparently the presence of pits on the abdominal sternites in these two genera is only analogous, because the genera Alleloplasis and Fovealvus gen. nov. clearly differ in the structure of the male and female genitalia and belong to different families ( Gnezdilov 2007). Similar analogous sensory organs are known also for Cixiidae (the tribe Bennini Metcalf, for instance, Bennaria praestans Walker, 1857 ) ( Holzinger et al. 2002, fig. 10e) and the tribe Bennarellini Emeljanov, for instance, Noabennarella costaricensis Holzinger & Kunz, 2006 ( Holzinger & Kunz 2006, fig. 12), and Achilixiidae ( Achilixius spp. and Bebaiotes spp.) ( Wilson 1989, figs 4–6).