ABSTRACT Genitalia are rich source of characters in insect taxonomy. Usually, they are examined after dissection and cleaning with potassium hydroxide (KOH), procedure that may damage both genital morphological structures and intracellular molecular contents. Enzymatic procedure with Proteinase K has been used to clean muscle off the genitalia while extract DNA, but its damage to the genital structures has not been evaluated. Herein, we qualitatively compare the use of KOH and Proteinase K to prepare genital structures in minute insects (Hymenoptera: Bethylidae). We show that Proteinase K is better to preserve the genital structure and provides quality DNA.

ABSTRACT It is difficult to make reliable sex associations in several species of Hymenoptera due to sexual dimorphism. Only a few species of the flat wasp genus Dissomphalus Ashmead, 1893 have had their sexes associated, since females are rarely collected and differ morphologically from their conspecific males. Collecting couples during their phoretic copula is difficult, but it is the most reliable way to associate the sexes in Dissomphalus . Herein, we associate the sexes and discuss the mating system based on couples of six Dissomphalus species collected during copulation: D. bisserratus Azevedo, 1999, D. connubialis Evans, 1966, D. rettenmeyeri Evans, 1964, D. simulatus (Evans, 1969), comb. nov., D. mendicus Evans, 1969, and D. firmus Redighieri & Azevedo, 2006. The females of the latter three are described for the first time. The distribution of two species is expanded. Apenesia simulata Evans, 1969 is transferred to Dissomphalus and is now D. simulatus comb. nov. Finally, we briefly discuss the genital structures used during phoretic copulation, analyzing the male and female genitalia in copulation. During copulation, the mating female is attached to the male only by the genitalia and is apparently grasped by muscles attached to the male's metasoma.

Apenesia aurita sp. nov., from southeastern Brazil, is described and illustrated. Apenesia angusticeps Evans, 1963, A. tenebrosa Evans, 1963, A. pallidicornis Evans, 1963, A. quadrimera Leal & Azevedo, 2001 and A. crenulata Kieffer, 1910 are recorded for the first time to the State of Espírito Santo.