2011 Annual Report
1a.Objectives (from AD-416)
Develop pest management methods for paper wasps that are invasive on Tinian and other islands in the Marianas.
1b.Approach (from AD-416)
Chemical attractants and baits will be tested to determine efficacy against Tinian Island wasps. Pheromones will be identified to produce possible attractants. Optimized lures and traps will be evaluated as tools to reduce wasp populations.
This project relates to NP 304 2A, Protection of Agricutural and Horticultural Crops, Biology and Ecology of Pests and Natural Enemies because invasive paper wasps are direct pests of soft fruits and a stinging hazard to farm workers.
What was done. The species makeup and abundances of invasive stinging wasps were assessed on Tinian, Saipan and Guam islands at two times of the year. This included identity and counts of nests per unit area on transects through forest, and the identity of over 200 wasps captured by net. On Tinian, the dominant wasp is Polistes stigma, on Guam is Ropalidia marginata, and both P. stigma and R. marginata on Saipan. Also, Polistes olivacea was abundant at the US Navy Base on Guam, possibly in association with buildings on which it places nests.
A series of chemicals known to attract other types of wasps were tested against Polistes stigma on Tinian Island, and were not effective. A series of sweet baits were then tested, again against Polistes stigma on Tinian Island, and were weakly effective.
Polistes stigma wasps were seen to spend much time foraging at open flowers. Six species of flowers were identified that were visited often by these wasps, with potential to look for kairomonal attractants based on floral odors.
This work directly relates to objectives one and three from the related in-house Project Plan because of the depredations of invasive paper wasps on cherry fruits and grapes, and the stinging hazards of invasive social wasps for farm workers picking fruit.
Monitoring of activities and progress on this project was accomplished by direct supervision of on-site employees, and use of site visits, email and telephone to communicate with off-site collaborators.