SOUND PRODUCTION IN SCOLYTIDAE (COLEOPTERA) WITH EMPHASIS ON THE GENUSIPS

Abstract

AbstractThe "pars stridens–plectrum" terminology of stridulatory organs is discussed. A list of 77 species of Scolytidae known or presumed to bear stridulatory structures is presented. The three types of scolytid stridulatory organs, vertex–pronotal, gula–prosternal, and elytra–abdominal tergites, are described and discussed.All North American species in the genusIpswere examined for stridulatory organs. The gula–prosternal type was found on females, and possibly males, ofI.concinnus(Mannerheim) andI.mexicanus(Hopkins). The vertex–pronotal type occurs on females of 14 other species. No stridulatory structures were found on either sex of the remaining 17Ipsspecies. Females of 15 of the 18 pine-infesting species have stridulatory organs, while 14 of the 15 spruce-infesting species apparently lack them. FemaleI.confusus(LeConte) stridulate when entering the male entrance tunnels. Removal of the stridulatory organ has two effects: males do not permit some of these non-stridulating females to enter, and they deny entry to others for an unusually long period of time.Possession of a stridulatory apparatus in the Scolytidae appears to be associated with the sex opposite to that which initiates the entrance tunnel.No significant differences were found between gallery systems constructed by femaleI.confususwith the stridulatory organ removed and those constructed by stridulating females except that more single stridulating females excavated two or more egg galleries from a nuptial chamber.