Articles
Preliminary findings on the improved monitoring of walnut husk fly (Rhagoletis completa) through a new pheromone lure
Article number
1420_40
Pages
309 – 318
Language
English
Abstract
The walnut husk fly (WHF), Rhagoletis completa Cresson, is a serious pest of walnuts in the United States and has increased in importance over the past 30 years.
Early season WHF infestation results in reduced nut weight, edible yield weight and light kernel color and increased adhering husk, mold and shell staining in all cultivars.
Control of WHF has relied on repeated insecticide applications.
Initiation of the spray program and monitoring the efficacy of the spray program are based on captures of adult flies in yellow panel traps baited with an ammonium carbonate lure.
An improvement in monitoring through increased catch would aid in determining the proper time to initiate an insecticide control program and aid in determining the efficacy of the control program.
With the discovery of the male produced WHF pheromone (δ-hexalactone and δ-heptalactone), increased trap catch in combination with ammonium carbonate is possible.
Preliminary field evaluations of polymeric δ-hexalactone and δ-heptalactone lures showed that the lactones are aggregation pheromones, that the lactone lures in combination with ammonium bicarbonate lures increased trap catch over ammonium bicarbonate lures and lactone lures alone, and the load rate of lactone lures need to be at least 200 mg to have a field longevity of 4 to 5 weeks.
Early season WHF infestation results in reduced nut weight, edible yield weight and light kernel color and increased adhering husk, mold and shell staining in all cultivars.
Control of WHF has relied on repeated insecticide applications.
Initiation of the spray program and monitoring the efficacy of the spray program are based on captures of adult flies in yellow panel traps baited with an ammonium carbonate lure.
An improvement in monitoring through increased catch would aid in determining the proper time to initiate an insecticide control program and aid in determining the efficacy of the control program.
With the discovery of the male produced WHF pheromone (δ-hexalactone and δ-heptalactone), increased trap catch in combination with ammonium carbonate is possible.
Preliminary field evaluations of polymeric δ-hexalactone and δ-heptalactone lures showed that the lactones are aggregation pheromones, that the lactone lures in combination with ammonium bicarbonate lures increased trap catch over ammonium bicarbonate lures and lactone lures alone, and the load rate of lactone lures need to be at least 200 mg to have a field longevity of 4 to 5 weeks.
Publication
Authors
R.A. Van Steenwyk, S.S. Walse, D. Kuzmich, M.R. Thayer, J.P. Rijal
Keywords
δ-hexalactone, δ-heptalactone, walnut husk fly, Rhagoletis completa, walnuts
Groups involved
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