Ewanius, Reid, 2002

Reid, C. A M., 2002, A New Genus Of Chrysomelinae From Australia (Coleoptera: Chrysomelidae), The Coleopterists Bulletin 56 (4), pp. 589-596 : 589-592

Ewanius , new genus

Figs. 1–10

Etymology. This genus name is derived from my son’s name, Ewan, and the gender is masculine.

Type Species. The type species is Ewanius nothofagi new species.

Diagnosis. Adult: head ( Figs. 1–2 ): median part of frons and clypeus flat, without grooves; head evenly contracted behind prominent eyes; antennae situated on anterior margin of head; clypeus distinct, transverse triangular; labrum not densely setose, with 3–4 pairs of discal setae; mandible with two apical teeth and small translucent area at base of iner margin, membranous penicillus absent; last segment of maxillary palpi quadrate, with truncate apex, and penultimate segment triangular, not grooved to receive apical segment; mentum transverse but almost quadrate, with straight apical margin; thorax ( Figs. 1–6 ): pronotum with single large seta in a pit on the raised margin of each angle; anterior margins of prothorax shallowly concave; lateral and anterior margins of pronotum bordered, border extending slightly upon posterior margin; hypomeron without grooves or excavations; prosternal process evenly

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curved towards anterior of prosternum; procoxal cavities open, hypomeral lobe short, less than half width of procoxa; elytral humeri prominent; epipleuron narrow but entirely visible from sides, sloped at ca. 45° from vertical, attenuated to raised margin just before apex, without fringing setae; anterior elytral wingbinding patch on small ridge on third from base; median portion of mesosternum visible and mesosternal lobe broad and truncate; vein AA3+4 reduced to short stub; metasternum with simple narrowly ridged margins; metendosternite with narrow and curved apical lobes; tibiae without ridges on external faces; third tarsal segment not bilobed, apex truncate or shallowly concave; claws appendiculate; abdomen ( Figs. 7–10 ): all ventrites free, not fused; ventrite I with broad, truncate, intercoxal process and entirely narrow basal border; apex of ventrite V depressed and apically internally lobed in male, simple in female; tegmen short and V­shaped; penis short and simple with small basal foramen and flagellum not heavily sclerotised; ovipositor re­ duced to paired sclerotised patches of tergite VIII and sternite VIII, pair of one­segmented palpi with translucent apices and slightly sclerotised ventral edge of paraprocts.

Pupa: the pupa of Ewanius is unknown.

Larva: similar to Novacastria (Selman and Lowman 1983) : elongate, without pseudopoda on the apical sternites but with transverse swellings of soft cuticle on sternites 2–7 (ambulatory ampullae), body setae short (not longer than half depth of head in any instar), eggbursters absent from first­instar, 3­ segmented antennae not set on prominent angular lobes without extrusible glands. There are at least three instars.

Distribution and Biology. The genus Ewanius is restricted to montane forest in central Tasmania, Australia. The host plant is Nothofagus (Nothofagaceae) . Females are ovoviviparous and lack spermathecae. There are four larval instars and the first lack eggbursters. Larvae and adults feed on leaf laminae. Pupation is unknown but presumably in soil as in other Gonioctenini ( Takizawa 1976, 1989; Reid 1992).

Figures

Fig. 1. Ewanius nothofagi sp. nov., male, colour pattern on left, sculpture on right. Scale bar = 1 mm.

Figs. 2–6. Ewanius nothofagi new species. 2) lateral view; 3) prothoracic venter; 4) mesosternum; 5) metendosternite; 6) claw. Scale bar = 1 mm (except Fig. 6).

Figs. 7–10. Ewanius nothofagi new species. 7) male sternite VII; 8) female sternite VII; 9) aedeagus, dorsal and lateral, with endophallus everted; 10) female genitalia (tergite VIII, ovipositor, sternite VIII).