2012 Annual Report
1a.Objectives (from AD-416):
1. Description of the biology of invasive termites species in Hawaii, particularly Coptotermes gestroi.
2. Assessment of novel wood preservatives and engineered woods products for use in regions like Hawaii with high-risk structures from termites.
3. Improve baiting and targeted soil insecticide applications by integrating the control techniques with new knowledge about termite foraging behavior.
1b.Approach (from AD-416):
Objective 1: Coptotermes gestroi has been identified by ARS researchers and university cooperators as the principle new invasive termite species threatening Hawaii and the continental USA. Field sites for termite collection and monitoring will be established and we will quantify tunneling patterns of Asian subterranean termite in comparision to Formosan subterranean termite that could affect control methods, using laboratory arenas.
Objective 2: Determine wood preference of Asian subterranean termite and assess efficacy of novel wood products in laboratory assays.
Objective 3: Quantify tunneling patterns of Asian subterranean termite in comparison to Formosan subterranean termite that could affect control methods, using laboratory arenas. We will determine environmental characteristcs correlated with Asian subterranean termite infestation in Hawaii.
Genetic analyses of Formosan subterranean termite populations from Hawaii, Japan, China, and the continental USA revealed that termite populations on Oahu, Hawaii, are very similar to those in southern China, and that multiple termite introductions have occurred in the USA; including at least two distinct introductions on the island of Maui. Hawaii is very likely the source of termite introduction to New Orleans, and from New Orleans, LA, to North Carolina. Termite populations in Hawaii are unique in comparision to those in other regions in that they appear to reproduce frequently by “budding” in which part of a termite colony gradually breaks away and forms an independent new colony. In other research, an extensive analysis of 50 years of termite biological control research led to the conclusion that effective biological control has never been conclusively demonstrated with subterranean termites, and that laboratory studies reporting positive results generally have little biological relevance and have not led to positive field results or subsequent commercialization. Continued trapping of termite alates (reproductives, or swarmers) in Hawaii demonstrated that swarming by the newly invasive Asian subterranean termite overlaps that of the Formosan subterranean termite, but appears to extend later into June and July, in agreement with result reported last year. Comparison of the tunneling patterns in the soil by these two termite species demonstrated that the Asian subterranean termite does not tunnel as great a distance as the Formosan, indicating that it is adapted more for searching for wood in the tropics than is the Formosan. The Asian termite was also less active in finding wood during periods of cool weather than the Formosan, suggesting that the Asian species may not spread to cooler regions where the Formosan occurs (higher elevations in Hawaii or further north in the continental USA). Finally, studies of the impact of stress due to disturbance on termite feeding showed that disturbance stimulates increased feeding by the Formosan subterranean termite, providing evidence for the observation occasionally made by pest control professionals of sudden termite infestation occurring in structures in the vicinity of soil-disturbing construction activities.