ALABAGRUS (Braconidae: Agathidinae)

DIAGNOSIS
HABITUS
        These are relatively large 4-12 mm and usually brightly colored with shades of orange, yellow, and black, though some species are entirely black. (fig. 1)
HEAD
        Gena normal to expanded posteroventrally, often posterolateral corner is acute but this state is found is several other agathidine genera. (fig. 2)
        The 3^rd (penultimate) labial palpomere is less than ½ as long as the last (distal) palpomere. (fig. 3)
        The frons is bordered with carinae, i.e., there are carinae extending from the lateral edges of the antennal sockets that extend posteriorly towards the ocelli. (fig. 4)
        The face is not elongated into a rostrum as in most species of Agathis and Cremnops. (fig. 2)
MESOSOMA
        The notauli may or may not be impressed.
        Propodea range from evenly areolated with 8 or 9 areola to completely smooth. (fig. 5)
        The tarsal claws all have a large, quadrate basal lobe. (fig. 6)
        The hind tibia almost always has more than 2 distolateral pegs, and there may be more than 20. (fig. 7)
        The 2nd cubital cell of the forewing is usually triangular though it may be weakly quadrate in some species. The wings are always pigmented and vary from black to yellow. (fig. 8)
        The hind coxal cavities are always closed. (fig. 9)
METASOMA
        The first median tergite of the metasoma (gaster) is convex or it has an anteromedial bump or median longitudinal ridge. Rarely (two species) there are two anterolateral carinae that converge on the midline. (fig. 10)
        The ovipositor (when fully exerted) is as long as the metasoma to almost twice the length of the body. (fig. 11)

BIOLOGY
All members with known biology are internal koinobiont parasitoids of larval Pyralidae. The first instar larva is attacked and the host dies in the prepupal stage after it has spun it pupal chamber. The only published accounts of biology are those of Hummelin (1974) and Needham (1955) who studied A. stigma and A. texanus respectively.

DISTRIBUTION
Restricted to the New World, from southeastern Canada (1 species) to northern Argentina. They are most diverse in wet, lowland, tropical areas and are rarely encountered over 1500 meters. distribution map

KEYS TO SPECIES
Sharkey (1988) revised all known species; Leathers and Sharkey (in press) described 7 new species from Costa Rica and revised the key to all known species to include these. An interactive key to species is on the web at the following address http://www.uky.edu/~mjshar0/datasets

DIVERSITY
113 species are described. Costa Rica has been well sampled with Malaise traps over many years. There are 31 described species from Costa Rica and another 7 or so (in my collection) yet to be described from Costa Rica. I guess that there are about 70 undescribed species in the World.

REFERENCES
Hummelen, P.J. 1974. Relations between two rice borers in Surinam, Rupela albinella (Cr.) and Diatraea saccharelis (F.) and their hymenopterous larval parasites. Mededelingen landbouwhogeschool, Wageningen 74 (1): 1-88.

Leathers, J. and M.J. Sharkey (2001). Alabagrus (Hymenoptera: Braconidae) of La Selva, Costa Rica with a key to species of the World. Contributions in Science (in press).

Needham, J.G. 1955. Notes on a leaf-rolling caterpillar and on some of its associates. Ecology 36: 346-352.

Sharkey, Michael J. 1988. A taxonomic revision of Alabagrus (Hymenoptera: Braconidae. Bulletin of the British Museum (Natural History) 57(2): 311-437.