Showing papers by "James H. Cane published in 1995"

Susceptibility of Ips calligraphus (Germar) and Dendroctonus frontalis Zimmermann (Coleoptera: Scolytidae) to coleopteran-active Bacillus thuringiensis, a Bacillus metabolite, and avermectin B1.

Abstract: A simple, reliable feeding bioassay was developed for screening certain biorational insecticides with potential use against pine bark beetles. Adult Ips calligraphus and Dendroctonus frontalis were fed freeze-dried phloem fortified with Avermectin B1, Bacillus thuringiensis with known coleopteran activity, or a bacterial metabolite (R003). Avermectin B1 was toxic to adult I. calligraphus by 4 days at an LC50 of 0.36 μg AI/g of diet. R003 was active against both beetle species, yielding 85–100% mortality after 10 days exposure to a concentration of 360 μg/g of diet. No B. thuringiensis product was toxic at a discriminating concentration of 200 μg of spore/crystal preparation per gram of diet. Beetle mortality on untreated diet remained <10% over the 4–10 days duration of feeding trials. Unadulterated, lyophilized phloem diet did not spoil during bioassays, provided that tanned beetles were taken for bioassays before they emerged from their natal host bolts. Microbial products with scolytid activity, such as Avermectin B1 and R003, could have future value for limiting bark beetle infestations of individual trees or small stands in urban or ecologically sensitive forests. Innovative strategies for delivery would have to be developed, however, to circumvent the cryptic habits of these phloeophagous beetles.