2012 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. Documents reimbursable with Dept. of Navy/DOD. Log 40366. Formerly 5352-22000-017-56R (6/10); 5352-22000-019-22R (1/11).
The species makeup and abundances of invasive stinging wasps were assessed on Tinian and Saipan islands in March. This included identity and counts of nests per unit area on transects through forest, and the identity of over 100 wasps captured by net. On Tinian, the dominant wasp was Polistes stigma,with small numbers of Ropalidia marginata, while R. marginata was more abundant than P. stigma on Saipan. This pattern was similar to that seen in 2011. Densities of nests appeared to be reduced over 2011 samples. A set of floral-based chemicals were tested as potential aggractants for Polistes stigma on Tinian Island, and were found to be ineffective as trap lures. The flowers of one species of shrub were visited by these wasps, and in great numbers. Multiple air samples from over these flowers were collected for laboratory analysis of the floral scent. A preliminary analysis of these samples revealed a list of compounds that might be evaluated in the future as wasp attractants. The work reported here addresses objective 1 and 3 of the parent project plan.