Melanterius maculatus

Pinzón-Navarro, Sara V., Jennings, Debbie & Oberprieler, Rolf G., 2017, Host associations of Melanterius Erichson (Coleoptera: Curculionidae: Cleogonini), with a diagnosis and delimitation of the genus and description of five new species, Zootaxa 4298 (1), pp. 1-77 : 8

The M. maculatus group

The easiest species group to delineate is the M. maculatus group, which is characterised by the females having the uncus of their pro- and mesotibiae arising from the outer (upper) angle of the tibiae ( Figs. 2, 4, 6, 8 ) and which includes species such as M. acaciae Lea, 1899 , M. antennalis Lea, 1899 , M. castaneus Lea, 1899 , M. ellipticus Lea, 1913 , M. fasciculatus Lea, 1913 , M. maculatus Lea, 1899 , M. servulus Pascoe, 1872 and M. submaculatus Lea, 1928 . The same condition of the uncus occurs in several Lybaeba species, e.g. L. amplipennis ( Lea, 1899) , L. hybrida ( Lea, 1913) , L. insignita (Elston, 1919) and L. squamivaria Lea, 1909 , indicating that the maculatus group may only be a natural one if it includes these species. In most other species of both genera the uncus of the pro- and mesotibiae of the females arises from the inner (lower) angle, as it does in the males ( Figs. 1, 3, 5, 7 ) and as is typical in uncinate weevils, but in some Lybaeba species it arises from more or less the middle of the apical edge of the tibiae (an intermediate condition). The shape, direction and angle of the uncus is often useful in the distinction of species. It is not currently possible to delimit the M. maculatus group on characters of the males.

Figures

FIGURES 1 – 13. Diagnostic structures of some Melanterius species. 1 – 8: apex of left protibia, odd numbers – males, even numbers – females (arrows showing point of origin of uncus); 1 – 2: M. acaciae Lea; 3 – 4: M. castaneus Lea; 5 – 6: M. maculatus Lea; 7 – 8: M. servulus Pascoe. 9: ventrites of M. ventralis Lea, male (arrows showing lobed posterior margin of ventrite 1 and setose median area of ventrites 3 – 5). 10: antennal funicle and club of M. ventralis (arrow showing flattended ventral surface of club). 11 – 13: elytral declivities (arrows showing arrangement of costate interstriae); 11: M. castaneus; 12: M. maculatus; 13: M. servulus.