2013 Annual Report
The bacterium Liberibacter that causes zebra chip is rapidly transmitted to potato by the potato psyllid and pesticides may have limited disease control as they may not kill the insect fast enough to prevent its transmission to potato. Therefore, there is an urgent need to develop management tools that have deterrence and repellency effects to potato psyllid feeding and egg oviposition. Laboratory and field experiments assessed feeding deterrence effects of Cyazypyr insecticide on potato psyllid to prevent or minimize transmission of zebra chip. It was found that foliar applications of Cyazypyr are effective in deterring feeding and killing the potato psyllid within 24 hours, thereby suppressing the psyllid population rapidly. However, the product did not prevent transmission of Liberibacter to potato plants by the potato psyllid as its does not stop feeding during the first six hours, crucial period during which the potato psyllid can effectively transmit Liberibacter to potato plants. Information from this research is very useful and will be incorporated in integrated pest management programs for potato psyllid control to help potato growers rapidly suppress populations of this psyllid and minimize losses due zebra chip.