Publication Date


Document Type


Committee Members

Donald Cipollini (Committee Member), Jeffrey Peters (Committee Member), John Stireman III (Advisor)

Degree Name

Master of Science (MS)


Tachinid parasitoids in the subfamily Phasiinae are important natural enemies of heteropteran bugs. Host location by these flies occurs via antennal reception to the pheromones of their hosts; however little is known regarding the mechanisms which underlie host selection. Halyomorpha halys, the invasive brown marmorated stink bug, represents a potential novel host species in North America. This study was conducted to determine the suitability of H. halys as a host for phasiine species, and to assess cues used in host selection by the species Gymnoclytia occidua. Field attraction to pentatomid pheromones by both phasiines and pentatomids in Southwest Ohio were investigated and preliminary laboratory host-selection experiments were conducted. In 2015, from June 23 to September 16 pyramid-type traps were baited with three pentatomid-pheromone lures and were monitored in agricultural and semi-natural locations. Trap catches included specimens from seven different phasiine species and three different pentatomid species. Host movement is an important factor in parasitoid attraction to host models, this attraction was not affected by pheromone presence, choice and no-choice trials indicate that Gymnoclytia occidua females do not discriminate against H. halys. However, no parasitoids were successfully reared from H. Halys. Field parasitism by a Gymnoclytia occidua female on H. halys was directly observed, and both adults and nymphs of H. halys were found bearing parasitoid eggs in the field. These results suggest that H. halys may be a “sink” for Gymnoclytia occidua and possibly other native phasiine parasitoids in North America.

Page Count


Department or Program

Department of Biological Sciences

Year Degree Awarded


Included in

Biology Commons