The acasta conundrum: Polymorphism and taxonomic confusion within the parasitoid genus Melittobia (Hymenoptera: Eulophidae) Author Matthews, Robert W. Author González, Jorge M. text Zootaxa 2008 1854 45 54 journal article 10.5281/zenodo.274436 34ba49f6-55b5-4414-9f26-e491df98bfa7 1175-5326 274436 Other M. megachilis synonymies In his catalog, Peck (1951) synonymized Pteromalus gerardi Hickok with M. megachilis ; it is unknown whether he saw actual specimens. Unfortunately, the types of P. g e r a rd i may be lost (T. Nuhn, 1/30/2008 , in litt .); the type deposition is not listed on Noyes’ (2003) web site. Hickok’s (1875) brief description of the male P. g e r a rd i is superficially similar to Dahms’ (1984a) description of male M. femorata , but a careful reading of Hickok (1875) suggests that P. g e r a rd i actually may prove to be a senior synonym for M. digitata . Hickok (1875, p. 134) notes each male antenna “has a strong spine, projecting inward, giving it the appearance of the antler of a deer.” This seems a clear reference to the distinctive mesal projection on the scape of M. digitata that is the basis for the specific epithet ( Dahms 1984a, his figs. 197–198 ); this is the only species of Melittobia that possesses such a structure. Further behavioral support is provided by the observation ( Hickok 1875, pp. 134–135 ) that “… the males have but few opportunities of coming in collision; but when this occurs one of the males is quite sure to forfeit his life. If one succeeds in grasping the other around the neck or waist with his mandibles he holds firmly on, and drives them slowly through nerve and muscle of his victim, till the lifeless trunk and abdomen fall asunder.” As noted above, M. femorata males are relatively tolerant of one another and seldom engage in fatal combat, but males of M. digitata are vicious fighters ( Hartley & Matthews 2003 ). Unfortunately, until Hickok’s types are located, exact species identification must remain as speculation. Dahms did not examine the syntypical series of 13 females that Brues (1909) named as Chrysocharis aeneus . We obtained them from MCPM and, as noted above, confirmed that they are also M. megachilis , with an average head length to genal width of 1.3; all had 4 setae on the submarginal vein and a pair of setae on the submedian lobes of the scutellum. We have designated one of the females as Lectotype .