BIOLOGY OF TRICRANIA-STANSBURYI, A MELOID BEETLE CLEPTOPARASITE OF THE BEE OSMIA-LIGNARIA-PROPINQUA (HYMENOPTERA, MEGACHILIDAE)

A life-cycle chronology of Tricrania stansburyi (Haldeman) developed from results obtained in this study demonstrates that this meloid species is univoltine, individuals mate more than once as they emerge from host nests, dispersal is accomplished by flight, adults apparently do not feed and are short-lived (1-2 wk), fecundity is high (>900 eggs per female), parasitism is accomplished through phoresy by the first instar (triungulin), meloid larvae develop through seven instars, the entire host cell provision is consumed by the first five instars (sixth and seventh instars do not feed), and only one meloid larva survives multiple parasitism of any host cell. Results were also obtained on courtship, mating, sex ratio (female-biased), preferred egg deposition sites, new host records (7 species), preferential discrimination of triungulins to various host species, function of silken strands produced by triungulins, environmental triggers that initiate combat between triungulins, and biological traits that influence annual rates of parasitism by T. stansburyi.