Testing of the insect pest control fungus Beauveria bassiana in grass shrimp Pslaemonetes pugic

Abstract

Embryos, larvae and adult grass shrimp Palaemonetes pug10 were exposed to spores of the insect-control fungus Beauvena basslana Conidiospores attached to embryos held by gravid females and remained wlth the egg mass for at least 6 d In the first experiment where individual developing embryos contained in test tubes were exposed to conidiospores of B basslana. 2 of the 75 embryos became infected and died, and a third was abnormal at hatch In Expt 2 a repeat experiment, no adverse effects were observed In subsequent expenments, attempts were made to increase the probability of infection or abnormal development for embryos exposed to B basslana Strategies for these attempts included lowering the salinity, adding a carbon source for the fungus to the test water, or rendenng embryos free of potentially protective symbiotic bacteria with a n antibacter~al agent All attempts were unsuccessful in promoting infection or abnormal development B bassiana did not cause any adverse effects duling shnmp larval development In adult shrimp lethal infections only occurred in specimens injected with eithei conldiospores or blastospores of B bassjana