Melobasis costipennis, Kerremans

Levey, Brian, 2018, A revision of the Australian species of the genus Melobasis Laporte & Gory 1837 (Coleoptera: Buprestidae), Part 2 (Revision of the nervosa species group), Zootaxa 4528 (1), pp. 1-79 : 17-18

M. costipennis Kerremans

(Figs 32–33, 88–89, 139–140, 171, 176)

Melobasis costipennis Kerremans 1898:124 ; 1903:159; Carter 1923:81; 1929:285; Obenberger 1930:432; Bellamy 2002:155; 2008:1325. Stat. rev. (not syn. of M. lathami (Laporte & Gory)) .

Type locality: Australia .

Type specimens examined. Holotype ♂ ( BMNH) Australie Chevrolat / costipennis Kerr. Type / Collection Chevrolat / Kerremans 1903 -59 / HOLOTYPE Melobasis costipennis Kerr. B. Levey det. 1995.

Other specimens examined. Western Australia: Applecross; Barren Range; Badgingarra, 5 km S.; Boxwood

Hill; Bremer Bay, 23 km N.N.W.; Bullsbrook; Busselton; Cape Arid N.P.; Cranbrook; Dunsborough; Eneabba, Hill River; Esperance; Fitzgerald River; Forrestfield; Jandakot; Lake Pooraricup, Tenterden; Mundura; Meelup Beach; Midland Junction; Monument Hill; Naval Base; Nedland; Peak Charles; Perth; Point Perron; Spencers Brook; Stirling Range; Wanneroo. Specimens in AMSA, ANIC, BLC, BMNH, CLBC, IRSNB, MVMA, NMPC, QMA, SAMA, TMSHC, UQA, WADA, WAMA, ZMHB.

Diagnosis. General diagnosis: length 9.2–12.2 mm; upperside in ♂ usually emerald green, or golden green, occasionally olive green; in ♀ usually blackish green or black bronze sometimes with extensive reddish purple or coppery reflections; underside and legs in ♂ golden green, the legs sometimes with coppery reflections; in ♀ usually reddish purple or blackish purple, sometimes golden green; underside laterally sparsely clothed with short silvery pubescence, most of prosternum, prosternal process, mesosternum, and central parts of metaventrite and abdominal ventrites glabrous or very sparsely pubescent.

Head: as in M. rubromarginata .

Antenna: as in M. rubromarginata .

Pronotum: 1.43–1.61 × as wide at base as long in midline; other characters as in M. rubromarginata but pubescence sparser and scarcely visible from above.

Scutellum: as in M. rubromarginata .

Elytra 2.39–2.76 × as long as wide at base; other characters as in M. rubromarginata .

Hypomeron: as in M. rubromarginata .

Prosternum: as in M. rubromarginata .

Mesanepisternum (Fig. 176): shiny, with shallow round seate bearing punctures in the anterior half, posterior half microreticulate without large punctures, posterior half in ♀ sometimes only very weakly microreticulate, shiny.

Central part of metaventrite, inner part of metacoxa, central part of abdominal ventrites glabrous or sparsely pubescent, more sparsely and weakly punctate than lateral parts of these structures which are densely punctate with lunate punctures, with sparse moderately long silvery pubescence.

Apical ventrite (Figs 139–140): lunate punctures not coalescing near the lateral margin, not forming grooves; excision in ♂ broad, W shaped, with a moderately broad curved flange at the centre, with long well developed parallel lateral spines (Fig. 139); ♀ narrower, U-shaped, with a moderately broad flange for its entire width, which is often slightly bisinuate, the lateral spines well developed, parallel to slightly divergent (Fig. 140).

Fore tibia: ♂ strongly curved, with a very small triangular tooth at apex, and a slightly developed setal brush on the anterior face at the apex; ♀ tooth absent or very small, and tibia less strongly curved.

Mid tibia: ♂ strongly curved with an elongate depression along the ventral face; ♀ weakly curved and without a depression.

Aedeagus (Figs 88–89): parameres strongly constricted before the apical setae bearing part; apical setae bearing parts scarcely widened, about one third total length of the parameres, apical half weakly chitinised, with numerous fairly long, slightly curved, spine-like setae, in addition to the usual long fine setae; median lobe subtruncate at the tip.

Ovipositor: not examined.

Comments. This species is likely to be mistaken for M. dissimilis due to its colour dichromatism, (see differences in the comments section of M. dissimilis ).Overall it is most similar to M. rubromarginata . The sexual dichromatism of M. costipennis is one significant difference from M. rubromarginata , although not absolute as some females resemble males in colour. The slight difference in the apex of the median lobe of the aedeagus, the shape of the flange of the apical ventrite of the male, and the microreticulate sculpture of the posterior half of the mesanepisternum in M. costipennis , are probably the only definitive ways to distinguish these two species. The adult host records suggest that the larval hosts may be different.

Bionomics. Adults have been collected from October to February, most records in December & January. Adults collected on Acacia spp., A. cyclops , and A. rostellifera . Larval host Acacia saligna .