Rhopalosoma hispaniola Lohrmann, 2019

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 : 35-38

Rhopalosoma hispaniola Lohrmann sp. nov.

LSID (species): urn:lsid:zoobank.org:act:6BEECB2C-0403-4F5C-93DF-04590CF406DA

LSID (author): urn:lsid:zoobank.org:author:05A758C9-462A-422C-B8D6-DD9530E2BD05

( Figs. 4 , 5 )

Diagnosis

Within Rhopalosoma , females of R. hispaniola are unique in showing the following character combination: hind wing Rs ∗ is straight and recurrent, and the apical 0.65 of fifth tarsomeres is tapered. Males of R. hispaniola resemble R. minus Townes, 1977 , in having a straight, recurrent hind wing Rs ∗ but can be differentiated by the position of the fore wing cu-a, which is distad of M 1 by about 1.0 × its length (about 2.0 × in R. minus ).

Currently, the genus is represented in the Caribbean only by Rhopalosoma poeyi Cresson, 1865 , and R. haitiense Townes, 1977 ( Townes, 1977). However, neither of these species has a similar hind wing Rs ∗.

Material

Holotype: female, MB. I 5915 , in Miocene amber from the Dominican Republic ; the specimen is deposited in the amber collection of the Museum für Naturkunde Berlin. The specimen is almost completely preserved without any significant distortions. However , large parts of the legs are missing. The following syninclusions have been observed: one Collembola and one Mymaridae .

Paratype: male, MB.I 6046, in Miocene amber from the La Bucara mine in the Dominican Republic; the specimen is deposited in the amber collection of the Museum für Naturkunde Berlin. The specimen is completely preserved without any significant distortions. In order to access crucial characters of the fossil the amber piece has been cut into two fragments. The following syninclusions have been observed: two Hymenoptera ( Mymaridae ), four Diptera, one Isoptera, one large Isoptera wing, one unidentified Insecta, and one Araneae.

Description

Female ( Fig. 4 ). Measurements. Total body length (head, without antenna, plus mesosoma plus metasoma) in lateral view 12.0 mm. Maximum head width in dorsal view 2.0 mm. Flagellar length (measured on left antenna with the last segment added from the right antenna) 11.4 mm (including pedicel and scapus 12.1 mm). Mesosomal length in lateral view 3.2 mm. Fore wing length 8.9 mm. Hind wing length 6.5 mm. Metasomal length in lateral view 7.8 mm.

Head. (Base of right flagellum and last flagellomere of left flagellum not preserved.) FI–FV each with a pair of apical bristles. FI shorter than FII, which is about as long as flagellomeres III– V. FVI–FX becoming sequentially shorter from base to apex. Inner margin of compound eye emarginate. Depth of eye notch about the same size as the width of torulus. FI 5.0 ×, FII 8.2 ×, and FVII 9.5 × as long as wide. TL 0.6 ×, OOD 0.25 ×, and MOD 1.0 × LOD.

Mesosoma. Scutellum about half as long as mesoscutum and approximately 3 times as long as metanotum. Mesosternal lobes present, separated from mesosternum by slight constriction.

Fore wing. With eight enclosed cells: C, R, 1Cu, 1 R 1, 2 R 1, 1Rs, 1M, and 2Cu. Costal cell very narrow, apically slightly wider, over complete distance narrower than bordering veins. Cell 1Rs about 1.05 × as long as cell 1 R 1. Vein 1cu-a slightly bowed, distad of M 1 by about 1.0 × its length. Distance between 1cu-a and M 1 about half the distance between 1cu-a and m-cu. Vein Rs 1 straight, about 0.8 × length of M 2. Pigmented traces of 2m-cu present. Anal cell without longitudinal spurious vein at its center (present in some Recent Asian Paniscomima ). Pterostigma narrow.

Hind wing. Rs ∗ straight, recurrent, its anterior section meeting Sc + R at an angle of about 55 ◦. M diverging far beyond cu-a. With two clusters of hamuli. Basal hamuli straight. With 13 distal hamuli, all of same size and curved- and/or hook-like.

Legs. (The following parts of the legs are not preserved: tarsomeres III and following of right fore leg, tarsomere II and pretarsus of left fore leg, distal two-thirds of tarsomere I and tarsomere II of right mid leg, tarsomeres II–IV of left mid leg, distal half of tarsomere I and following of both hind legs.) Fore leg with one tibial spur. Mid leg and hind leg each with two tibial spurs, inner spur of hind tibia at base with dorsal tuft of bristles (calcar). Tarsomeres II–IV with apicolateral fenestrae. Pretarsal claws toothed medially ( Fig. 4c ). Arolia large.

Metasoma. Segment I about as long as mesosoma. Sting upcurved ( Fig. 4a ).

Pilosity. Body and wing membranes covered with regular distributed fine, short setae.

Male ( Fig. 5 ). Measurements. Total body length (head, without antenna, plus mesosoma plus metasoma) about 7.3 mm. Maximum head width in oblique ventral view about 1.0 mm. Flagellar length (measured on left antenna in ventral view) 5.7 mm (including pedicel and scapus: 6.2 mm). Mesosomal length in lateral view is about 2.3 mm. Fore wing length about 5.6 mm. Hind wing length about 3.8 mm. Metasomal length about 4.3 mm.

Head, mesosoma, and metasoma as in female except the following. Fore wing cell 1Rs about 0.85 × as long as cell 1 R 1. Vein Rs1 about 1.25 × length of M 2. Distance between 1cu-a and M 1 about the same length as the distance between 1cu-a and m-cu. Hind wing Rs ∗ meeting Sc + R at an angle of about 50 ◦. With eight distal hamuli. Plantar lobe present on tarsomeres I–IV. Pretarsal claws bifid. Metasomal segment I only two-thirds the length of mesosoma. Cuspis with ∼ 12 peg-like bristles on apical section and ∼ 6 apical setae. Digitus with ∼ 33 peg-like bristles on apical section. Paramere spine-like, upcurved. Cercus paddle shaped and with apical setae.

Note

The intraspecific variation between the non-sex-specific characters (e.g., ratio of the length of fore wing veins Rs 1 and M 2, ratio of the length of fore wing cells 1Rs and 1 R 1) seems to be slightly higher than in the Recent species of Rhopalosoma . However, we chose a conservative approach by assigning both specimens to the same species rather than describing two species based on only a single specimen of each sex.

Etymology

The specific epithet refers to the island of Hispaniola in the Caribbean where the fossils were found. It is a noun in apposition.

Figures

Figure 4. Rhopalosoma hispaniola sp. nov.: female, holotype, MB.I 5915, Miocene Dominican amber. (a) Overview. (b) Detail of the head in dorsal view. (c) Detail of the tarsal claws. (d) Distal section of mid tibia with tibial spurs. (e–f) Details of the right fore wing. Abbreviations used in (b) and (c): en – eye notch, lo – lateral ocellus, mo – median ocellus, oc – occipital carina, tc – tarsal claw, t5 – tarsomere 5, and pat – preapical tooth.

Figure 5. Rhopalosoma hispaniola sp. nov.: male, paratype, MB.I 6046, Miocene Dominican amber. (a) Overview. (b) Posterior metasoma with genitalia. (c) Details of right fore wing. (d–e) Details of right fore and hind wing with labeling of fore wing cells and venation (d) and labeling of hind wing venation (e). Abbreviations used in (b): ce – cercus, cu – cuspis, di – digitus, pa – paramere, pv – penis valve, tg6 – tergite 6, and tg7 – tergite 7.