New taxonomic status for Anteon faciale and A. pseudohilare (Hymenoptera: Dryinidae)


J.T. Burn & J. de Rond.

BURN, J. T. & J. DE ROND, 1999. NEW TAXONOMIC STATUS FOR ANTEON FACIALE AND A. PSEUDOHILARE (HYMENOPTERA: DRYINIDAE). - ENT. BER., AMST. 59 (1): 10-12.

Abstract : The status of Anteon faciale (Thomson), previously considered a junior synonym of A.ephippiger (Dalman), is restored and the male is described. Anteon pseudohilare Burn was compared with the holotype of A. faciale, and found to be identical.

J. T. Burn, 1 Sycamore Avenue, Armthorpe, Doncaster, South Yorkshire, DN3 3HQ England.
J. de Rond, Beukenhof 96, 8212 EB Lelystad, The Netherlands.

Introduction

The description of Anteon pseudohilare Burn, 1990 was based on a single female, found in a museum collection. After collecting several specimens in their natural habitat, the author was able to send some material to fellow hymenopterologists. When the second author received one of these females, he recognised an older species in it. While doing some research on the synonyms of Anteon ephippiger (Dalman, 1818), de Rond had come across the description of Anteon faciale (Thomson, 1860), which in no way appeared to agree with the type of A. ephippiger. Examination of the holotype of A. faciale, the only specimen upon which the species was based, finally proved the true identity of the British females: A. pseudohilare is indeed a junior synonym of A. faciale.
No records of males were found in literature, so the male associated with the British females is described below as the allotype. A recent description of the female is given by Burn (1990).

Anteon faciale (Thomson, 1860), stat. nov.

Anteon pseudohilare Burn, 1990: 185-186, syn. nov.

Type material
Holotype: F, Sweden, labelled with five minute printed cards; "Bhn" [= Boheman (leg.)] "Gl." [=Gotland], "Sc.", "Thoms." , "Type." No additional information on type locality or date in Thomson (1860).
Allotype: M , England, Hightown (Lancashire), 3.vii.1996, J.T. Burn.
Paratypes (labelled Anteon pseudohilare): 1F, England, Freshfield (Lancashire),1.vii.1953, S. Shaw; 1F, Hightown, 30.vi.1996, J.T. Burn; 2 F, Hightown, 1.vii.1996, J.T. Burn; 5F , Hightown, 3.vii.1996, J.T. Burn; 1F, England, Raven Meols Hills (Lancashire), 1.vii.1996, J.T. Burn. The allotype will be deposited at the British Museum (Natural History), London, UK.

Description of the male (figs 1-5)
Fully winged; Length approximately 2.5 mm; Black, antennae brown, slightly paler ventrally, more noticeably so on the scape.
Head: Frons and vertex with strong and close punctation, sculpture stronger behind the ocelli; Mandibles yellow, teeth brown.
Thorax: Pronotum, scutum, scutellum and metanotum with strong and close punctation; propodeum fully reticulate rugose, with double arched transversal keel between anterior and posterior surfaces, posterior surface with two longitudinal keels.
Abdomen: segments 6 and 7 with exceptionally strong pits. Legs testaceous, femora infuscate, hind coxae two thirds black; Wings hyaline, with distal section of radial vein half as long as proximal section, stigma dark brown; Parameres with distal inner process pointed, dorsal membranous process large.

Discussion

For the construction of determination keys many of the older authors have relied completely on details that are now known to be variable. Olmi (1984, 1994) therefore characterised most older descriptions as insufficient or unreliable, but gave no additional information on types of synonymized species. Trusting completely on his expertise it was virtually impossible to suspect the true identity of A. faciale. Why Anteon faciale was synonymised with A. ephippiger, while both species obviously have little in common, can be explained by a stong emphasis on colour. Some varieties of the latter species, for instance var. collare (Dalman), are not completely yellow, but black with reddish spots on the head and pronotum. The dark frons and yellow clypeus of A. faciale however, are quite the opposite of the reddish frons and black clypeus of A. ephippiger var. collare.
According to Thomson (1860) the colour, the thin antennae and the coarse punctures on the mesonotum made A. faciale easy to differenciate from others.
Anteon ephippiger is known to have fine, sparse punctures on the head, scutum and scutellum. The scutellum and metanotum are flat in A. ephippiger, while convex in A. faciale.
The holotype of Anteon faciale is pinned through the mesonotum. The pin obliterates more than one fourth of the mesonotal surface, but what remains is covered with a distinct coarse punctation. In lateral view the mesoscutum, scutellum and metanotum are just as strongly convex as in A. pseudohilare, The punctation on the head is slightly weaker in the type of A. faciale. The brown shade of the dark parts in the type is probably due to aging. The yellow facial markings, still brightly contrasting with the dark forehead in the more than 137 years old type, appear to be identical to those in A. pseudohilare. The colouration of the antennae, legs and body are similar, the overall length is shorter; 2.9 mm, compared with 3.3-3.6 mm. for A. pseudohilare. The transverse keel of the propodeum is double arched in dorsal view in all specimens.
The types of Anteon ephippiger (Dalman) and A. ephippiger var. collare (Dalman) have very few microscopical punctures on the vertex and mesonotum. The males of Anteon gaullei Kieffer are perhaps the most likely to be confused with A. faciale. The punctation in the latter species is considerably stronger on the distal half of the scutum and the last tergite, and the antennal segments are longer and of lighter colour.

All the Lancashire sites are characterized by coastal sand dune vegetation, and all the specimens were obtained by searching on all fours amongst Marram grass (Ammophila arenaria (L.) Link). The Hightown specimens were from a small area on the fore-dunes, where there was relatively little, or no undergrowth amongst the Marram. The Raven Meols Hills specimen was taken much further inland on the lower slopes of a blow-out dune. The habitat of the Swedish record is not known.

Acknowledgements

With special thanks to Mr. Lars-Åke Janzon, at the Swedish Museum of Natural History, Stockholm, who was very helpful in sending us Thomson's type on loan and a copy of the original description.

References.