Foraging and nontarget use by Trissolcus japonicus

Trissolcus japonicus is an exotic parasitoid that is a potential biological control agent for brown marmorated stink bug. Much of the research on T. japonicus has focused on detection and redistribution but there has been less on the ecology, including foraging, of T. japonicus. We studied the foraging behaviors and nontarget host use of T. japonicus in a series of laboratory and field experiments. We found that wasps were relatively poor foragers in the lab and often accepted nontarget hosts in similar proportions to BMSB when given foraging opportunity. Fitness of T. japonicus was relatively lower on most nontarget species and BMSB was still preferred when eggs were given in close proximity. In the field, parasitism was relatively low overall with no observable attack on nontarget species by T. japonicus. Implications for biological control of BMSB are discussed.