Submitted to: Annals of the Entomological Society of America
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/5/1999
Publication Date: N/A
Citation: Day, W.H., Baird, C., Shaw,, S.R. 1999. A new native species of Peristenus parasitizing (Hym:Braconidae) Lygus hesperus (Hem:Miridae) in Idaho: biology, importance, and description. Annals of the Entomological Society of America. 93(3): 370-375 Interpretive Summary: Peristenus digoneutis, a small wasp from Europe that we released, is now established in 7 northeastern states. It has reduced tarnished plant bug numbers by 75% in New Jersey alfalfa, and we have begun investigating its effectiveness as a biological control agent in strawberries. Because the western tarnished plant bug is a serious pest of alfalfa grown for seed in we also released P. digoneutis there. While checking for its establishmen discovered another (previously-unknown) native parasite. This new species soon be named, in another publication. We found that it is parasitizing a surprisingly high percentage of the pest, 80% in generation 1, and 50% in generation 2. Studies in Idaho are warranted, to learn if insecticide use alfalfa can be reduced, without lowering seed yield. If successful, this w crop production costs, and reduce insecticide side effects on leafcutter be are necessary to pollinate this crop. We have also released the Idaho spec cDelaware, to determine if it can establish in the midatlantic region, because digoneutis is not present south of New York City.
Technical Abstract: Lygus hesperus and L. lineolaris are major pests of seed crops, fruits, co- tton seedlings, and vegetables in the U.S. Our laboratory has established Peristenus digoneutis (Hymenoptera:Braconidae) in the northeastern U.S. Its high parasitism rates in alfalfa, an extensively-planted forage crop, reduced L. lineolaris numbers by 75%. We and cooperators have found P. digoneutis in 7 northeastern states, and have released it in other areas of the U.S. While trying to recover this parasite from alfalfa grown for in Idaho, where it had been released for 3 years, we discovered a new species. This new species parasitized 81% of 1st generation nymphs in 1998 and 49% in the 2nd generation (average of 1997 and 1998), so it is highly effective. Studies are underway to determine if it can be established in the mid-Atlantic states (P. digoneutis is not present south of New York City) to control L. lineolaris, and if this new species is sufficiently effective in Idaho so insecticide use on seed alfalfa can be reduced.