PREY SPECIFICITY OF ADULT TEMNOCHILA-VIRESCENS F (COL, TROGOSITIDAE), A PREDATOR OF IPS-GRANDICOLLIS EICHH (COL, SCOLYTIDAE)

Temnochila virescens, a bark beetle predator from the southeastern USA, was imported into Australia in 1981 as part of a biological control program for Ips grandicollis, the five-spined engraver beetle. To meet quarantine requirements, studies were carried out to determine the prey-specificity of predator adults. In tests of prey acceptability, T. virescens rejected Rose aphids (Macrosiphum rosae), Citrus aphids (Toxoptera citricidus), Iridomyrmex spp. ants, Ladybird beetles (Coccinella repanda), and German cockroaches (Blattella germanica); and accepted Confused flour beetles (Tribolium confusum), Rice weevils (Sitophilus oryzae), Golden-haired bark beetles (Hylurgus ligniperda) and Black pine beetles (Hylastes ater) as prey. The effect of a non-scolytid diet on adult T. virescens longevity, fecundity, and on egg viability was also tested. Those predators fed T. confusum adults laid significantly fewer eggs and were much shorter-lived than those fed I. grandicollis adults, although viability of eggs did not differ between treatments. The significance of these results in terms of gaining release approval for T. virescens, and its status as a bark beetle predator, are discussed.