Embolemus micropterus, OLMI & GUGLIELMINO & MÜLLER & CAPRADOSSI & PERKOVSKY, 2021

OLMI, MASSIMO, GUGLIELMINO, ADALGISA, MÜLLER, PATRICK, CAPRADOSSI, LEONARDO & PERKOVSKY, EVGENY E., 2021, Descriptions of the first females of Embolemus (Hymenoptera: Chrysidoidea) from Kachin (Myanmar) amber, Palaeoentomology 4 (1), pp. 44-49 : 46

Embolemus micropterus sp. nov.

( Fig. 2A, B )

Holotype. Female specimen No. DAF3304 deposited in DAFS.

Etymology. The species is named micropterus , because of the very reduced wings (from the Greek words mikrós - (= short) and - pteron (= wing)).

Diagnosis. Micropterous female of Embolemus ( Fig. 2A, B ), with forewing apparently reduced only to tegula.

Locality and horizon. Kachin amber (mid- Cretaceous, lower Cenomanian , about 99 Ma) .

Description. Female. Micropterous ( Fig. 2A, B ); length ca. 2.3 mm. Colour apparently brown-testaceous. Antenna geniculate, filiform, articulated on two prominent contiguous frontal processes, slightly shorter than head + mesosoma + metasoma (24:37); antennomeres in following proportions: 14:5:4:5:5:5:5:5:5:9. Head slightly pyriform (length/breadth ratio: 20:13), alutaceous, apparently bare, with dorsal side slightly convex; anterior region of dorsal side slightly tapering ( Fig. 2A ); ventral side of head, occipital carina, ocelli, frons, temple and vertex not visible through the amber thickness. Palpi not visible. Mesosoma about as long as metasoma, about twice as long as head (39:20), almost completely darkened, so that morphological characters of pronotum, mesoscutum, mesoscutellum, metanotum, mesopleuron, metapleuron and metapectal-propodeal complex are not completely visible. Pronotal tubercle reaching tegula. Fore wing reduced to tegula (length 0.07 mm) ( Fig. 2C ). Hind wing absent. Metasomal petiole short. Tibial spurs 1/2/2.

Male. Unknown.

Remarks. It is possible that E. brachypterus and E. micropterus are the opposite sex of one of the species described by males. The extreme sexual dimorphism of the Embolemidae prevents the association of the opposite sexes based on the morphology. This explains why in extant Embolemidae eight species are known only by females and 21 by males. Males and females of extant species can be associated by rearing or DNA analysis. Of course, these methods are not feasible to apply to species in amber. This difficulty results in two separate keys for females and males of Embolemidae .Another consequence of this situation is that it is possible that species based on males are really the opposite sexes of species based on females.

Figures

FIGURE 2. Embolemus micropterus sp. nov., female holotype DAF3304. A, Dorsal view. B, Ventral view. C, Fore wing. Arrows indicate the fore wings reduced, as long as tegulae. Scale bar = 0.5 mm for A and B; 0.1 mm for C.