1a.Objectives (from AD-416):
The objectives of this project include: . 1)evaluation of existing and novel monitoring tools for the brown marmorated stink bug (BMSB)in commercial apple orchards;. 2)defining relative host preference and susceptibility of apple compared with other relevant crops;. 3)evaluating the efficacy of currently labeled insecticides to manage the BMSB in apple orchards; and. 4)identify novel attractants for use in monitoring traps.
1b.Approach (from AD-416):
The BMSB has emerged as an extremely destructive pest of tree fruit throughout the mid-Atlantic. The intent of this work will be to develop effective monitoring and management tools for the BMSB in apple orchards. The work will be conducted in collaboration with affected commercial growers over a two-year period.
Several projects have been initiated to develop monitoring and management tools for brown marmorated stink bug (BMSB). A demonstration trial in commercial apple and peach orchards in northern and central Virginia compared a prescribed insecticide program with grower standard programs against BMSB and other direct pests. The prescribed program was developed and based on insecticides that showed the greatest efficacy against BMSB in laboratory bioassays. Three baited pyramid traps deployed per block (prescribed and standard programs) were monitored weekly. Fruit injury was assessed monthly, based on destructively sampling 100 fruit per block, and will continue through harvest. A project designed to determine the incidence of BMSB injury on apple and peach fruit at discrete intervals throughout the fruiting period will improve our understanding of risk periods based on current pest pressure in northern Virginia provided additional information on the expression of injury and its severity at harvest based on when it occurred. Sets of 50 fruit are exposed to natural BMSB populations for ~30 day intervals throughout the growing season and otherwise, protected by enclosing them in screened exclusion cages. The study was initiated in May and uses 'Redhaven' peaches and 'Golden Delicious' apples. Peaches and apples were harvested in late July and late September, respectively. This study is being repeated for a second season. A related project determined how injury from BMSB feeding during the final weeks before harvest was expressed at harvest and after a period in cold storage. 'Red Delicious' apples were placed in screened exclusion cages in early spring. Adult BMSB were introduced to sets of 20 fruit for seven-day intervals beginning four weeks prior to harvest. We also found that it takes ~3 weeks for expression of injury on apple after feeding by BMSB. This study is being repeated for a second season. At harvest, fruit were assessed for external injury, then placed in cold storage for evaluation of injury at regular intervals. Two separate studies examined the effect of aging on the efficacy and longevity of the attractant lure and kill strips used in BMSB monitoring traps. Sets of kill strips and lures were field-aged for zero, one, two, three, or four weeks, and then deployed in traps for two weeks in late summer. We found that likely because of high release rates of commercial lures, lures were no longer attractive after several weeks. We also found that kill strips likely were active over several weeks, aiding in retention of captured bugs.