Jocelyn G. MILLAR-1, Qiso WANG-1,2, and Richard E.
RICE-1
1-Department of Entomology, University of Califomia, Riverside CA
92521, U.S.A.;
2-Current Address, Department of Plant Science, Massey University,
Private Bag 11222, Palmerston North, New Zealand;
3-Department of Entomology, University of California, Davis CA 95616,
U.S.A.
The plant bugs Phytocoris relativus and P. californicus have been shown to cause significant damage in pistachio orchards. Damage includes lesions, kernel necrosis, and premature nut abortion. Bugs can move into a nut crop quickly from the natural vegetation surrounding orchards, or from other crops in adjacent fields. Infestations can be difficult to detect by currently available sampling methods (beating tray sampling) until significant damage has occurred. Consequently, our objective was to identify attractive pheromones for these insects for potential use in efficient and sensitive monitoring programs.
Preliminary investigations determined that virgin female bugs were attractive to males. Comparison of volatiles collected from sexually mature virgin females and virgin males revealed that females produce at least four sex-specific compounds. A series of field bioassays was used to determine that blends of only two compounds were required to aUract male bugs. Furthermore, the attraction was highly specific; only mature male bugs were attracted, confirming that the attractive blends are indeed sex pheromones.