Chewobrachys Constant

Constant, Jerome, 2008, Revision of the Eurybrachidae (XIII). The new Australian genus Chewobrachys (Hemiptera: Fulgoromorpha), Zootaxa 1898, pp. 41-54 : 43-45

Genus Chewobrachys Constant n. g.

Figs. 1–5 .

Type-species: Eurybrachys sanguiflua Walker, 1858 by original designation.

Etymology. The name is formed by the juxtaposition of Chew, in honour of Mr Peter Chew and his children Tony and Sandy, whom I wish to thank for their contribution to a better knowledge of the life history of several species of Eurybrachidae found around Brisbane (see also Constant 2005, 2006c), and brachys (Greek) = short, which is a common ending of generic names among the Eurybrachidae . Gender arbitrarily feminine following the use within the family.

Diagnosis. Medium sized (12–16 mm), brown, convex insects. Recognized by the following combination of characters: (1) frons slightly convex, 2 times broader than long (fig. 2), (2) infra-ocular spines on genae absent, (3) tegmina slightly convex (figs 24–28), (4) first fork of vein M beyond Sc-R separation (fig. 1), (5) clavus closed (fig. 1), (6) hind wings well developed, brown with base red and white markings apically (figs. 24–27), (7) abdomen and ventral face bright red (figs. 24–27), (8) ventral face of first hind tarsomere with obsolete pad of microsetae (fig. 4–5). Known only from Australia.

Description. General coloration: brown to grey-brown, often suffused with olivaceous, with white waxy markings, abdomen bright red.

Head: about as broad as thorax; vertex about 4 times broader than long, concave with fore and hind margins curved and carinate; frons twice broader than long (fig. 2), barely visible in dorsal view, convex, with dorsal margin slightly concave in normal view; disc longitudinally wrinkled; clypeus slightly surpassing fore coxae; labium surpassing median coxae but not reaching hind trochanters; apical segment longer than broad, acuminate, shorter and more slender than penultimate (fig. 3); no infra-ocular spine; small hump before ventral margin of eye; ocelli absent; antennae short, not visible from above, slightly surpassing lateral angle of frons but not eye; scape short, pedicel barrel-shaped.

Thorax: about 1.1 times broader than length of pro- and mesonotum together; pronotum with fore margin carinate and carina close and parallel to fore margin, obsolete in middle; anterior part of disc excavate, posterior part humped; mesonotum smooth.

Tegmina: nearly flat with apex slightly folded ventrad beyond clavus, elongate, about 2.5 times longer than broad; costal margin sinuate to slightly curved; apex roundly cuneiform; sutural margin sinuate; clavus closed.

Venation (fig. 1): vein C obsolete on basal 1/3, distinct on middle 1/3; veins Sc and R separated close to base; first fork of vein M beyond Sc-R separation; veins A1 and A2 fused at about 2/3 of length of clavus.

Hind wings: well developed; anal area well developed; sutural margin slightly trilobed; brown with base red and ante-apical whitish markings; apex rounded, not reaching apex of tegmen at rest.

Legs: fore and median femur and tibia dorso-ventrally flattened, slender; tibia III with 3 lateral and 9 apical spines (fig. 4); first hind tarsomere elongate, with ventral face bearing group of 12 spines near apex (fig. 4) and slight tubercle with obsolete pad of microsetae at interno-apical angle (fig. 5).

Genitalia ♂: pygofer short, slightly sinuate and narrower dorsally in lateral view (figs 6, 29); anal tube dorso-ventrally flattened, elongate, with anus at basal ¼ (figs 8, 31); gonostyli laterally flattened, convex and elongate, fused ventrally at base (figs 7, 30), with spiralate baso-dorsal process directed dorso-cephalad, dorsal margin strongly emarginate near apex, digitiform or pointed process at posterior 2/3 (figs 6, 29); periandrium with elongate, sclerified process directed postero-dorsally on each side of median, mainly membranous part; aedeagus sclerified, bifid apically, surpassing processes of periandrium (figs 9, 10, 32, 33).

Genitalia Ψ: anal tube elongate and narrow, curved postero-ventrad, slightly v-shaped in cross section beyond anus, lanceolate in dorsal view, laminate ventrally (figs 11, 14); gonoplacs unilobed, projecting dorsolaterad, longer than high, not surpassing anal tube (fig 11); gonapophysis IX large, apically rounded and curved dorsad (fig. 11); gonocoxae VIII looking like inflated pouch (figs 11, 13); gonapophysis VIII large, dorso-ventrally flattened, fused together and with sternite VII, rounded at apex (figs. 11, 12); sternite VII produced caudad, bearing ventrally two subapical processes (figs. 11, 12); anterior vagina small, membranous (fig. 11); posterior vagina strongly sclerified, short and broad basally, subtriangular apically; five–six strong, longitudinal ridges on each side of apical constriction (figs 11, 12, 15); bursa copulatrix attached dorsally, near base, oval-shaped, produced ventrally at base before vaginal connection, much larger than posterior vagina; walls bearing weak ornamentation (fig. 11).

Sexual dimorphism: females larger than males and white spots of hind wings smaller in dimension (figs 24–27).

Size: 12–17 mm.

Distribution: Eastern Australia (New South Wales and Queensland).

Biology. Species of this genus appear to be associated with plants of the genus Acacia (Mimosaceae) . All specimens for which the host-plant species is known with certainty have been collected on trees of the genus rather than on species that grow as shrubs. One specimen has also been collected at light, one in a house, two at interception traps and two in pitfall traps. The specimens examined have been collected from September to May.

Notes: (1) species of the Australian genus Olonia Stål, 1862 can show similarly coloured hind wings and abdomen but have a pad of microsetae ventrally on the first hind tarsomere, and very different genitalia with the gonostyli spinose. The Australian species Nirus corticeus Jacobi, 1928 also has similarly coloured hind wings and abdomen but has concave frons, a more elongate clypeus, and very different male genitalia (see also Constant, 2006a); (2) the species in the genus Chewobrachys can only be surely identified on the basis of the male genitalia. Females are difficult to separate but the combination of some morphometrical and colour characters seems to give fairly reliable results.

The females listed hereunder show characters that do not allow reasonably reliable identification: Queensland: 1 Ψ: Marsupial Creek, 94 km W of Georgetown (18°16'S 142°41'E), 200 m, 19.v-11.i.2000, pitfall, J. & P. Hasenpusch [QM]; 1 Ψ: Mazeppa N.P. (22°16'S 147°17'E), 240 m, 27.iii.2001, pyrethrum gidgee trunks, site 3, G.B. Monteith [QM]; 1 Ψ: Toowong (27°29'S 152°59'E), 3.iv.1920, S. Hainsworth [ANIC].

Figures

FIGURE 1. Chewobrachys, main veins of right tegmen. A 1: anal vein 1; A 2: anal vein 2, C: costal vein; Cu: cubital vein; M: median vein; R: radial vein; Sc: subcostal vein.

FIGURES 2 – 5. Chewobrachys sanguiflua. 2, frons, normal view. 3, labium, ventral view. 4, hind tarsus, ventral view. 5, first hind tarsomere, ventral view, detail of apex.