Melobasis, Laporte & Gory 1837, Laporte & Gory, 1837

Levey, Brian, 2023, A revision of the Australian species of the genus Melobasis Laporte & Gory 1837 (Coleoptera: Buprestidae), Part 3 (Revision of the azureipennis, cupricollis, iridicolor and melanura species groups), Zootaxa 5302 (1), pp. 1-100 : 44-45

The cupricollis species group

This species group is composed of five species found in humid and subhumid S.E. Australia from Victoria to S. Queensland, and the northern Brigalow Belt of Queensland. The species I have placed in this group all have the mesanepisternum densely punctured with small variably shaped punctures, which lacks reticulate microsculpture and large shallow setae bearing punctures. The sculpture of the mesanepisternum is similar to some species I have placed in the melanura species group e.g. M. costata Macleay and M. calama sp. n. The species of cupricollis species group have the clypeal excision shallow, U-shaped. This character is seen in many species of the nervosa and iridicolor species groups. The combination of the above mentioned two characters in the species of the cupricollis species group, is the only reason to suggest that these species belong to a single species group. Males of M. cupricollis Kerremans , M. ordinata sp. n. and M. jacquelinae Turner & Hawkswood have an almost straight mid tibia, without secondary sexual modification such as seen in the species of the melanura , iridicolor and nervosa species groups, and may indicate they are more closely related to one another than to any species in the latter three species groups. The inclusion of M. apicalis Macleay and M. conicollis Obenberger in the cupricollis group was initially based on the sculpture of the mesanepisternum and the form of the clypeal excision, when only the female holotype specimens of these species were known (the holotype of M. apicalis is missing it’s abdomen, but other characters indicate it is female). Recently two males and a female of M. apicalis have been seen, which suggest that this species may not be closely related M. cupricollis , M. ordinata sp. n. and M. jacquelinae . The male of M. apicalis has secondarily sexual modifications of the fore- and mid-tibia suggesting it is not closely related to the aforementioned species. It is unfortunate that M. conicollis is still only known from the female holotype, so its relationships are uncertain, however overall similarities suggest it might be closely related to M. apicalis . A case could be made for splitting this species group, but given the uncertainty as to the relationship of M. conicollis , and the fact that most of the putatively related species groups mentioned above are defined on very few characters, and also contain species that could be split off into other groups, I can see no advantage in erecting another small species group.

Key to the cupricollis species group

1 Punctation at sides of apical ventrite of abdomen coalescent and forming longitudinal grooves; punctation of hypomeron composed of large, shallow, ovate to ellipsoidal punctures, the flat bottoms of which are distinctly microsculptured ( Fig. 83 ); aedeagus with apex median lobe distinctly arrow-head shaped, the setae bearing apical portion of the parameres spoon shaped ( Figs 103, 104 ).................................................................... M. cupricollis Kerremans

- Punctation at sides of apical ventrite of abdomen with punctures well separated or contiguous but not forming longitudinal grooves; punctation of hypomeron composed of smaller, contiguous, mostly round, ovate or pentagonal punctures, the bottoms of which are not microsculptured ( Fig. 84 ); aedeagus with apex of median lobe not or only slightly arrow-head shaped, the setae bearing portion of the parameres not spoon shaped ( Figs 105–110 ).............................................. 2

2 Punctation of centre of prosternum and prosternal process very dense or contiguous, most punctures separated by less than half their own diameter ( Fig. 85 )............................................................................. 3

- Punctation of centre of prosternum and prosternal process less dense, most punctures separated by at least twice their own diameter ( Fig. 86 )..................................................................................... 4

3 Elytral apices broadly rounded, shape less elongate (Fig. 79).................................... M. apicalis Macleay

- Elytral apices subacute, shape more elongate (Fig. 80)..................................... M. conicollis Obenberger

4 Each elytron with indications of three costae, costae1 and 2 well defined, the punctation between costae 1 and 2 mainly arranged in more or less regular longitudinal series adjacent to each costa (Fig. 81); elytral microsculpture weak, the elytra shiny.................................................................................. M. ordinata sp. n.

- Each elytron with indications of at most two raised intervals, with at most only raised interval 1 costate, the punctation between raised intervals 1 and 2 not arranged in regular longitudinal series ( Fig. 82 ); elytral microsculpture stronger..................................................................................... M. jacquelinae Turner & Hawkswood

Figures

FIGURES 82–86. 82 dorsal habitus: M. jacquelinae Turner & Hawkeswood (♀ Stanthorpe, Q.) Scale bar = 5.0 mm; 83–84 hypomeron: 83. M. cupricollis Kerremans; 84. M. ordinata sp. n. 85–86 prosternal process: 85. M. apicalis Macleay (J Mt. Hopeful, Q. TMSHC); 86. M. jacquelinae Turner & Hawkeswood (J Berkshire Park, N.S.W. BLC). Scale bars = 1.0 mm.

FIGURES 101–106. 101–102 apical ventrite: 101. M. jacquelinae Turner & Hawkeswood (J); 102. M. jacquelinae Turner & Hawkeswood (♀). Scale bars. = 1.0 mm. 103–106 aedeagus & apex of parameres: 103–104. M. cupricollis Kerremans (Nepean Gorge, N.S.W. BLC); 105–106. M. apicalis Macleay (Mt. Hopeful, Q. TMSHC). Scale bars of aedeagus = 1.0 mm; scale bars for apex of parameres = 0.5 mm.