Rhopalosoma sp.

Lohrmann, Volker, Ohl, Michael, Michalik, Peter, Pitts, James P., Jeanneau, Laurent & Perrichot, Vincent, 2019, Notes on rhopalosomatid wasps of Dominican and Mexican amber (Hymenoptera: Rhopalosomatidae) with a description of the first fossil species of Rhopalosoma Cresson, 1865, Fossil Record 22 (1), pp. 31-44 : 39-40

Rhopalosoma sp.

( Fig. 6 )

Material

Female, MB.I 6549, in Miocene amber from Chiapas, Mexico; the specimen is deposited in the amber collection of the Museum für Naturkunde Berlin. The specimen is almost completely preserved, except for part of the antennae, but it is largely distorted, except for the wings and legs. In order to access the crucial characters of the fossil the amber piece has been cut into three fragments. The following syninclusions have been observed: one Hymenoptera ( Braconidae ), six Diptera, one Heteroptera, and one Thysanoptera.

Description

Head, mesosoma, and metasoma as in R. hispaniola except the following.

Measurements. Due to the heavy distortion of the specimen all measurements except for those of the wings, should be treated rather as an estimate of the general size. Body length (head, without antenna, plus mesosoma plus metasoma) in dorsal view 10.4 mm. Head width in dorsal view 1.4 mm. Mesosomal length in lateral view 2.9 mm. Fore wing length 8.2 mm. Hind wing length 6.3 mm.

Fore wing. 1Rs cell about 0.85 × as long as cell 1 R 1. 1cua slightly curved, distad of M 1 by about 1.0 × the length of 1cu-a. Distance between 1cu-a and M 1 about 0.7 × the distance between 1cu-a and m-cu.

Hind wing. Rs ∗ very slightly curved (almost straight), its anterior section recurrent, meeting Sc + R at an angle of ∼ 45 ◦, posterior section almost vertical. With 11 distal hamuli ( Fig. 6f ).

Note

This specimen resembles the female from Dominican amber. Unfortunately, many important characters, such as the size and position of the ocelli, form of the inner eye margin, etc., cannot be examined due to the insufficient preservation of the fossil. However, we do not include this specimen in the type series of R. hispaniola to emphasize its different geological origin and the slightly different wing venation as an indication of a separate distinct species which might be properly described and named after new material becomes available.

Currently, the genus is represented in Mexico only by Rhopalosoma simile Brues, 1943 , and R. obliquum Townes, 1977 ( Townes, 1977). However, neither of these species has a similar hind wing Rs ∗.

Figures

Figure 6. Rhopalosoma sp.: female, MB.I 6549, Miocene Mexican amber. (a) Overview. (b) Left hind tarsus. (c) Pretarsus with claws. (d– e) Details of left fore wing. (f) Details of right hind wing. Abbreviations used in (b) and (c): pat – preapical tooth, tc – tarsal claw, tf – tarsal fenestrae, t1 – tarsomere 1, t2 – tarsomere 2, t3 – tarsomere 3, t4 – tarsomere 4, and t5 – tarsomere 5.