The Bionomics of Certain Insects Associated with Oak Wilt with Particular Reference to the Nitidulidae1

Abstract

Studies of insects associated with oak-wilt (Endoconidophora fagacearum) trees and also with fresh tree wounds revealed that nitidulids were the most numerous of all insects present. In trapping experiments these beetles preferred fungus baits to artificial kinds. The life history of several forest inhabiting nitidulids was studied and found to be relatively short (21-25 days); seasonal history studies showed that species predominance varies with the seasons and that some species are present and active during every month of the year. A mutualistic symbiosis exists between the nitidulids and their associated fungi (Ophiostoma pluriannulata, Graphium rigidum and Endoconidophora fagacearum). Because of their special characteristics, the nitidulids meet most of the requirements for an effective vector of a fungus disease including oak wilt. The authors consider nitidulids to be important vectors of oak wilt in nature.