Since the bagrada bug became established in low desert winter vegetable production in 2010, growers and pest control advisers have quickly found that preventing excessive feeding damage on newly-established crops is critical to the economics of broccoli production.
Local surveys have estimated that the invasive stink bug annually infests more than 80 percent of the acreage in Arizona and southern California, resulting on average in more than 10 percent stand losses and plant injury to direct-seeded broccoli crops.
The potential for the pest to cause significant crop losses, coupled with the lack of biological control alternatives, has left little alternative but to control outbreak populations with foliar-applied insecticides.
Furthermore, since the bagrada bug can quickly cause significant feeding damage to seedling plants, effective insecticide treatments applied in the field need to be fast acting.
Currently, desert vegetable growers in Arizona and California rely heavily on frequent applications of pyrethroid insecticides to control adult infestations on seedling cole crops.
Given the magnitude of pyrethroid usage historically applied to desert vegetable crops, alternative insecticides are needed to protect desert cole crops from bagrada bugs and conserve the pyrethroid chemistry.
Among the newer classes of chemistry, foliar-applied neonicotinoids, including Venom/Scorpion, have been shown to effectively control bagrada bug adults. At planting, soil systemic applications of some neonicotinoids have not prevented the bagrada bug from damaging seedling broccoli plants.
Field trials in India
In other parts of the world, neonicotinoid seed treatments have provided protection against bagrada bug. In India, for example, field trials showed that planting mustard seeds treated with imidacloprid resulted in significantly lower plant damage from the bagrada bug.
Recently, Valent U.S.A. registered clothianidin as a seed treatment on broccoli under the name of Nipsit. Based on UA research, this technology provides another tool for broccoli growers to use in the annual battle against bagrada bug in the desert.
2012-2014 field trials conducted at the Yuma Agricultural Center evaluated the effectiveness of Nipsit (clothianidin) seed treatments for preventing bagrada bug feeding damage and yield loss in broccoli.
The evaluations care available online at http://uacals.org/3fc.
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