Use of a Baited Trap Crop for Stink Bug Management in Peaches

Use of a Baited Trap Crop for Stink Bug Management in Peaches

Summary

Two plots of cowpeas were investigated as a trap crop, planted between a woods and peach orchard, as a management tool to reduce fruit injury from stink bugs. Stink bugs were attracted in large numbers (average as high as 11/plant) to potted cowpea plants introduced into each plot and baited with aggregation pheromone. Stink bugs did not move to planted cowpeas until beans formed about 7-10 days before peach harvest, but at lower levels than were found on potted cowpeas. Brown stink bug was the most abundant species, followed by dusky and green stink bug, with peak populations occurring on plants from late June to early July. Inspection of peach trees revealed the presence of more stink bugs in rows adjacent to pea plots (East and North side) than in border rows on opposite (West and South) sides of the orchard without pea plots. Evaluation of fruit at harvest revealed a higher incidence of catfacing/scarring injury on trees adjacent to cowpea plots than on trees on opposite sides of the orchard without cowpea plots.

Objectives/Performance Targets

1. Use a baited trap crop of cowpeas to improve fruit quality and reduce late season fruit losses from stink bugs.

   Reduce dependence upon insecticides for stink bug control.

   Delay development of insecticide resistance by stink bugs.

   Reduce mite outbreaks and miticide application resulting from increased pyrethroid use to control stink bugs.

   Conserve insect predator populations which have been reduced or eliminated by increased pyrethroid use.

   Reduce insecticide residues on peach fruit.

   Introduce fruit growers to concept of using a trap crop for insect control.

Accomplishments/Milestones

During early May, a 30 x 100 ft plot of cowpeas was planted as a trap crop between the woods and border on the East and North side of an 8 acre Newhaven peach orchard in Hampshire County, West Virginia. Beginning two weeks later, 15 potted cowpea plants that had been raised in the greenhouse were introduced into each plot. A stink bug aggregation pheromone lure was also installed near each potted pea plant. Potted pea plants were replenished as needed, generally every 2 weeks and lures replaced every 4 weeks. Sampling of potted pea plants for 10 consecutive weeks, beginning in June, revealed that stink bugs were highly attracted to these plants, averaging as high as 11 stink bugs per plant. Populations peaked on potted cowpeas from late June to early July, with brown stink bug being the most abundant species, followed by dusky and green stink bugs. Stink bugs were not found on planted cowpeas until beans formed, about 7-10 days before fruit harvest, and numbers were less than on potted cowpeas. Monitoring of stink bugs on border rows on each side of the orchard revealed higher abundance in trees adjacent to cowpea plots than in trees on opposite sides of the orchard without cowpea plots.

Fruit growers were provided with an opportunity to tour cowpea plots as part of a Twilight Fruit Grower meeting on June 24.

Fruit were sampled and evaluated for stink bug injury on each side of the orchard from four rows at increasing distances from the orchard border. An average of rows adjacent to the two cowpea plots showed a slight trend towards increasing injury with increasing distance into the orchard, whereas injury was similar in all rows on the opposite sides of the orchard without cowpea plots. The average incidence of catfacing/scarring injury was almost 4% higher in trees adjacent to cowpea plots than in trees on opposite sides of the orchard without cowpea plots. Incidence of brown rot, which is aggravated by stink bug feeding, was significantly higher on trees adjacent to the cowpea plot on the East side of the orchard than on trees on the West side of the orchard without a cowpea plot. However, the reverse was true when comparing trees on the North side adjacent to the cowpea plot with trees on the South side without a cowpea plot.

Impacts and Contributions/Outcomes

Use of a baited trap crop of cowpeas is successful in attracting stink bugs. In addition to attraction into the cowpea plots, stink bugs are attracted in greater numbers to the border rows of peach trees adjacent to the cowpea plots, resulting in greater fruit injury as compared with trees that are not adjacent to cowpeas. It’s possible that the lures are drawing stink bugs away from the non trap crop side of the orchard, thereby lowering injury. It’s also possible that stink bugs attracted from the woods enter both the cowpea plots and the border rows of the peach orchard, resulting in higher fruit injury. In order to fully understand the outcome, and make improvements in trap crop design, additional studies are needed to determine the specific reason why stink bugs respond to the aggregation pheromone and from what distance they are attracted. This study provided 25 fruit growers with an opportunity to learn about the use of a trap crop as an alternative management strategy.

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