ENTOMOPHAGA-MAIMAIGA REPRODUCTIVE OUTPUT IS DETERMINED BY THE SPORE TYPE INITIATING AN INFECTION

The fungal pathogen Entomophaga maimaiga, infecting gypsy moth larvae (Lymantria dispar), produces hive types of spores; relatively short-li ved conidia are produced externally on cadavers and are actively eject ed to cause infection during the same season, while azygospores, produ ced within cadavers, are dormant after formation and survive unfavoura ble conditions. This is the first record providing experimental proof of differential reproduction resulting from infections initiated by th ese two types of spores. Cadavers of larvae that had died from infecti ons initiated by azygospores produced only conidia, regardless of host instar or relative humidity after host death. This is in stark contra st to infections initiated by conidia, which could yield either conidi a only, azygospores only or both spore types, with reproductive outcom e primarily influenced by host age. Production of only conidia from in fections initiated by azygospores increases opportunities for secondar y transmission during the eight week field season; if infections initi ated by azygospores produced azygospores, chances for amplification of infections with subsequent epizootic development would be decreased.