Gryon chrysolaum (Walker)

Polaszek, Andrew & Kolberg, Roberta, 2008, Rediscovery of Gryon chrysolaum (Walker) (Hymenoptera: Platygastridae) - an egg parasitoid of Holhymenia rubiginosa Breddin and Anisoscelis foliacea Fabricius (Heteroptera: Coreidae), Zootaxa 1968, pp. 39-44 : 40-42

Redescription of Gryon chrysolaum (Walker)

Gryon chrysolaum ( Walker, 1839)

Telenomus chrysolaus Walker, 1839: 80 . Holotype ♂ (by monotypy) [ BRAZIL] Bahia, 1312(?)a [C.R. Darwin col. August 1836] [B.M. TYPE HYM. 9.463].

Hadronotus chrysolaus (Walker) . Dodd, 1920: 352 (generic transfer)

Liophanurus chrysolaus (Walker) . Kieffer, 1926: 66, 84. (redescription, generic transfer, keyed).

Gryon chrysolaus (Walker) . Masner, 1965: 75. (generic transfer, type information).

Gryon chrysolaum (Walker) . Johnson, 1992: 381. (change of ending for gender agreement with Gryon - neuter)

Male ( Figs 1–6). The following redescription of the male of G. chrysolaum is based on the holotype and the three additional males reared during this study, and deposited at the Natural History Museum, London.

Colour: Black. Coxae and flagellum dark brown / black. Scape, mandibles and legs dark brown. Setation on mesosoma golden-brown, on metasoma white. Wings hyaline.

Morphology: Head transverse, 1.75x broader than long in dorsal view ( Fig. 1). Occipital carina complete, with crenulate border ( Fig. 1). Frons with robust polygonal sculpture, polygons separated by strong carinae, and lateral ocelli clearly set within polygons. Frontal depression deep, with prominent arched carina and transverse striae, laterally areolate ( Fig. 2). Inter-antennal prominence very well developed, clypeus protruding. Mandibles small, bidentate. Antennae filiform ( Fig. 3).

Mesosoma strongly arched ( Fig. 3), sculpture polygonal, similar to that on head ( Fig. 4). Metanotal bulge protruding further backwards than apex of scutellum. Submarginal vein with long, dark semi-erect bristles surpassing wing margin. Stigmal vein approximately 2x length marginal vein; postmarginal approximately 2x length stigmal. Tibial spurs elongate, slender, mid tibial spur approximately one-half length of corresponding basitarsus.

Metasoma ( Fig. 5) with T2 clearly longest tergite, medially 2x length T1 and more than 3x length T3. Sculpture of T1 with deep longitudinal channels across entire surface, apical halves of these channels being deep foveae. Sculpture of T2 and posterior tergites contrasting with that of T1, longitudinally reticulate. Metasoma laterally setose, T2 and remaining tergites also dorsally setose. Ventral metasoma ( Fig. 6) regularly punctate.

Female ( Fig. 7). Morphologically very similar to male. Antenna clavate, though not abrubtly, 6–7 segmented. A4–A7 contrastingly paler than other antennomeres.

Material examined: Holotype ♂, [ BRAZIL] Bahia, 1312(?)a [C. R. Darwin col. August 1836] [B.M. TYPE HYM. 9.463]. 3♂ BRAZIL: Rio Grande do Sul, Porto Alegre (30°01'S, 51°13'W) iii–v 2006, R. Kolberg, ex eggs of Holhymenia rubiginosa . 3♀ same data. 2♀ BRAZIL: Nova Teutonia, 27°11'B [S]. 52°23'L [W] 28.vii.1937 Fritz Plaumann B.M. 1937-656. 1♀ [ MEXICO]: Morelos, Cuernavaca. June H.H.S. Godman- Salvin Col. 1904-1. All specimens deposited in NHM.

Comments. The male holotype is in good condition considering its age, and is mounted on its right side on a card point, which is itself stuck to a card square. The entire left antenna, and the apical segment of the right antenna, are missing.

Although no collector's name is on the labels, there appears to be no doubt that the specimen was collected by Charles Darwin. Evidence for this comes from a variety of sources, including handwriting on the " Bahia " label, research by earlier taxonomists on a second Gryon holotype described by Francis Walker, and documented knowledge of Darwin's itinerary and collecting events ( Smith, 1987). He arrived in Bahia for the second time on the home leg of the Beagle voyage during the first half of August 1836, collecting a number of microhymenoptera and other insects by sweeping. “ Telenomus chrysolaus ” is, however, not among the insect species collected by Darwin that are catalogued by Smith (1987).