A NEW MEXICAN GENUS AND SPECIES OF DINOCAMPINI WITH SERRATE ANTENNAE (HYMENOPTERA: BRACONIDAE: EUPHORINAE)*

The cosmopolitan braconid subfamily Euphorinae (sensu Shaw 1985, 1987, 1988) comprises 36 genera of koinobiont endoparasitoids, which parasitize the adult stages of holometabolous insects or nymphs and adults of hemimetabolous insects (Muesebeck 1936, 1963; Shenefelt 1980; Loan 1983; Shaw 1985, 1988). Occasionally the parasitoids of holometabolous insects will oviposit into larvae as well as adults (Smith, 1960; David & Wilde, 1973; Semyanov, 1979), but this only occurs where larvae are ecologically coincident with adults, living and feeding on the same plants (Tobias, 1966). Obrycki et al. (1985) found that Dinocampus coccinellae (Schrank) will oviposit into all larval instars, and pupae, as well as adults; however, the highest percentage of successful parasitization occurred when adults were attacked. Only a few papers have discussed euphorines of Mexico in particular (Muesebeck 1955; Shaw 1987). The euphorine tribe Dinocampini was defined by Shaw (1985, 1987, 1988) to comprise three genera with ocular setae, antenna1 scape three times longer than wide, and labial palpus reduced to two segments. As far as is known, members of the tribe Dinocampini parasitize adult beetles; Dinocampus Foerster parasitizes Coccinellidae (Shenefelt 1980) and Ropalophorus Curtis parasitizes Scolytidae (Shenefelt 1960, Shaw 1988). The hosts of the third included genus, Centistina Enderlein, are not known. Because these genera are known only from females (Balduf 1926; Shenefelt 1960), it seems possible that females of the entire tribe are thelyotokous, reproducing parthenogenetically and producing only female progeny. The purpose of this paper is to describe a fourth genus of Dinocampini from Mexico. This new genus and species is remarkable because it has serrate antennae, unlike any other known braconid.


Psyche
The morphological terminology used in this paper is mostly that of Shaw (1985Shaw ( , 1987 and van Achterberg (1974). Microsculpture terminology is that of Harris (1979). Flagellomeres, from base to apex, are abbreviated as F l through F13.
Genus Betelgeuse Shaw, Type species: Betelgeuse aztecus Shaw, n. sp. Etymology: Following greek mythology, the constellation of Orion is depicted on astronomical charts as a sword-bearing hunter. Because females have a conspicuous sword-like ovipositor, this genus is named for the star Betelgeuse (pronounced "beetle-juice"), which is part of the constellation of Orion. The name is masculine.
Description: Head ( Fig. 2) transverse, in dorsal view 2.3X broader than long; surface sculpture coarsely and evenly rugose; eyes elongate oval, not bulging anteriorly beyond frons; eyes in anterior view distinctly converging ventrally; shortest inter-ocular distance 2X clypeus width; minute ocular setae present; median frontal carina weakly present, extending from midpoint of face to between antenna1 insertions; inter-antenna1 distance 3.25X socket width; scrobes not protuberant; scape elongate, gradually curved, gradually wider apically; scape length 4X width at apex; pedicel somewhat globose; flagellum 13-segmented, considerably shorter than body length; F1-F5 longer than wide, gradually wider apically, somewhat flattened, forming serrations antero-laterally, each serration terminating apically in a sharp point and a single long seta; F l 3X wider than apical width, F2-F5 each relatively shorter than preceding flagellomere; F6-F12 each compact, about as long as wide, segments gradually slightly thicker apically, each with a single long seta projecting dorso-apically; apical flagellomere 2X as long as wide, apically pointed; ocellar triangle small, distance between lateral ocellus and eye 4X distance between lateral ocelli; occipital carina complete; malar space short, slightly less than 114 eye height; malar suture indistinct; facial setae minute, not obscuring face; lower clypeal margin truncate; mandibles when closed overlapping for slightly less than half mandible length; maxillary palpus 5segmented; labial palpus 2-segmented.
Mesosoma with surface sculpture entirely coarsely rugose to rugo-punctate; notaulus and sternaulus indistinct from general
Diagnosis: In the key to genera of Euphorinae of the world by Shaw (1985) Betelgeuse will run to couplet 29, but will not key further because the scape configuration does not match either of the two alternatives at that point. In the identification manual for North American genera of Braconidae (Marsh et. a1 1987) Betelgeuse will run to couplet 212, where it keys out near Ecclitura Kokujev from which Betelgeuse can be distinguished by its distinctive serrate antenna. Indeed, it can be distinguished from any other braconid genus by this character alone.
Phylogeny: The phylogeny of euphorine genera was reviewed by Shaw (1985Shaw ( , 1987. Because the fore wing lacks the first segment of At least two putative synapomorphies suggest a sister-group relationship with Ropalophorus: flagellum reduced to 13 segments or less (8 in Ropalophorus), and propodeum produced dorso-laterally as distinct tubercles. The latter is particularly convincing as a synapomorphy since it does not occur elsewhere in the Euphorinae, and was previously known only in Ropalophorus. The monophyly of Ropalophorus remains indicated by its 8-segmented clavate flagellum (Shaw, 1985). These relationships are expressed as a cladogram (Fig. 4) modified from Shaw (1985Shaw ( , 1987. Body predominantly reddish brown except apex of antenna (F10-F13) and metasomal terga 2-7 infused with black; F6-F8 yellowish brown; wing venation dark brown; wing membrane hyaline except amorphous infused patch along basal vein and another below stigma; ovipositor sheaths dark brown; ovipositor yellowish brown.
Distribution: Known only from the type locality in Durango, Mexico.
Etymology: The specific epithet refers to the Aztec Indian tribe in Mexico. [Vol. 95 Figures 1-3 were prepared by Ms. Kathy Brown-Wing, who deserves much credit, especially for the care and meticulous detail applied to the habitus illustration. Thanks are due to Dr. M. Sharkey, Biosystematics Research Centre, Agriculture Canada, Ottawa, Ontario, for arranging the loan of these remarkable specimens and also for critiquing the manuscript. Additional thanks to Dr. P. M. Marsh, Systematic Entomology Laboratory, U.S. Department of Agriculture, c / o National Museum of Natural History, Washington D.C., who reviewed the manuscript as well, and provided many helpful comments. Special thanks are due to Dr. W. R. M. Mason, Biosystematics Research Centre, Agriculture Canada, Ottawa, Ontario, for collecting the specimens, recognizing their significance as a new euphorine genus, and calling them to my attention in the first place.

Psyche
Betelgeuse aztecus Shaw, a new euphorine braconid genus and species from Mexico is described and illustrated. Reasons for placing it in the tribe Dinocampini are given, and its phylogenetic position relative to other genera in that tribe is discussed.