Orthogonalys gigantea Benoit, 1951

Smith, David R. & Tripotin, Pierre, 2012, Trigonalidae (Hymenoptera) of Madagascar, Journal of Hymenoptera Research 24, pp. 1-25 : 5-8

Orthogonalys gigantea Benoit Figs 8 13

Orthogonalos gigantea Benoit, 1951: 143.- Paulian 1961: 206, fig. 79.

Orthogonalys gigantea : Weinstein and Austin 1991: 422.- Carmean and Kimsey 1998: 53, 54.

Type material.

Holotype female at MNHN, labeled “Muséum Paris," "Madagascar, Mgn l’Ambre,” “Muséum Paris 1.34 A. Seyrig," "TYPE [red]," "Orthogonalys gigantea sp. n. holotype ♀, det. P. L. G. Benoit 1951." Benoit (1951) described the species from "Madagascar: Montagne d’Ambre I.1934 (A. Seyrig ♀ holotype, au Muséum National d’Histoire Naturelle de Paris." The antennae are missing except first three antennomeres of left and first antennomere of right and parts are glued onto a piece of cardboard on the pin.

Additional specimen examined.

PROVINCE ANTSIRANANA: "Madagascar Nord, dct Diégo-Suarez, Analamerana, 80 m, 50 km SE Diégo, I-59, Andria R." (1 ♂, MNHN).

Description.

Female ( Fig. 8 ). Length, 14 mm. Head black; inner orbits broadly from top of eye through malar area and gena, clypeus except for median V-shaped stripe, and mandible except apex white ( Figs 11, 12 ). Mesosoma orange with hind corners of pronotum, lower anterior corner of pronotum, and metascutellum yellow. Legs dark orange; hind tibia and tarsus darker, nearly black. Metasoma dark orange with black spot at center of 1st tergite, small faint black spot at center of 2nd tergite, lateral and posterior bands on 3rd tergite, and most of tergite 4 except for white posterior margin; tergite 5 white; laterally and ventrally mostly yellow with black spot on 6th sternite and sheath black.

Antenna missing (see male). Head from above nearly straight behind, behind eyes slightly expanded, distance behind eyes about equal to eye length ( Fig. 12 ). Anterior width of mesoscutellum 0.8 × medial length. Metascutellum 2 × broader than long ( Fig. 10 ). Mesonotum shiny with closely set punctures, mostly separated by shiny interspaces 1-2 × puncture diameters. Propodeum with almost straight transverse carinae ( Fig. 10 ).

Male.

( Fig. 9 ). Length, 15 mm. Antenna black; antennomeres 11-16 and basal half of 17 white. Similar to female except apex of mesoscutellum more yellowish, metasoma mostly black above with reddish brown at apex of tergite 1 and on most of tergites 2 and 3, tergites 1-3 laterally and ventrally orange yellow and tergites 4-6 with white spots. Paramere dark orange.

Antenna with 28 antennomeres, otherwise similar to female. Paramere oval, about 1.4 × as long as broad, broadly rounded at apex ( Fig. 13 ).

Distribution.

Madagascar: Antsiranana.

Remarks.

The status of this species has been questionable. Carmean and Kimsey (1998) thought that it might be only a large form of Orthogonalys hova . Benoit (1951) described the species from a single female. He separated Orthogonalys gigantea from Orthogonalys hova by its large size (14 mm) and by the following: teeth of mandibles broad but not very long, the inferior tooth directed downwards; clypeus very thickened; antennal sockets closer together; punctation of scutellum sparser but stronger; propodeum broader than long, with transverse carinae complete and regular (not tangled and less strong); color identical except the white “atténué” on the head and sides of abdomen. We have not seen additional females but have examined one male that compares in color and structure with the holotype female and was collected not far from the type locality, and we consider them to be the same species.

After study of both sexes, we note a number of characters that justify treating Orthogonalys gigantea as a valid species. Size cannot be regarded as a valid character in trigonalids. However, in comparison to Orthogonalys hova , the specimens examined are consistently larger. The female holotype of Orthogonalys gigantea is 14 mm and the male is 15 mm, whereas the largest Orthogonalys hova female is 9 mm and males 5.0-9.5 mm, with most in the 7 mm range. We are not sure about the clypeus, mandible, punctation of the scutellum, and closeness of the antennal sockets as Benoit described; these do not seem significant. However, we emphasize the following characters: the sculpture of the propodeum of Orthogonalys gigantea is more transverse ( Fig. 10 ) than the more reticulate sculpture of Orthogonalys hova ( Fig. 16 ) and other Orthogonalys species; the color of both are similar, except that Orthogonalys gigantea has the metascutellum yellow and the male has the metasomal tergites mostly black whereas the metascutellum of Orthogonalys hova is orange and the metasomal tergites of the male are considerably orange; and the parameres of Orthogonalys gigantea are dark orange and rounded at the apex ( Fig. 13 ), whereas those of Orthogonalys hova are white and more acute at the apex ( Fig. 20 ).

This species is known only from northern Madagascar. The holotype and associated male were collected in the same area, around Diego Suarez, the two localities only about 50 km apart.

Figures

Figures 8 - 9. Orthogonalys gigantea. 8 Female holotype, dorsolateral view. 9 Male, dorsolateral view.

Figures 10 - 13. Orthogonalys gigantea. 10 Mesosoma, dorsal view, male. 11 Head front view, female holotype. 12 Head, dorsal view, female holotype. 13 Male paramere, lateral view (appearance is due to hairs matted against the surface).

Figures 16 - 20. Orthogonalys hova, male. 16 Mesosoma, dorsal view. 17 Head, front view. 18, Head, dorsal view. 19 Genitalia, dorsal view. 20 Apex of abdomen and genitalia, lateral view.