EFFECT OF A DECAY FUNGUS ON SUBTERRANEAN TERMITE (ISOPTERA: RHINOTERMITIDAE) RESPONSE TO BAIT TOXICANT TREATED WOOD

Abstract:
No choice feeding tests, Reticulitermes flavipes (Kollar) weekly survival and feeding on two bait toxicants was compared for sound sweetgum blocks and those decayed by Gloeophyllum trabeum (Pers. ex Fr.) Murr. At 100 ppm, imidacloprid and sulfluramid showed promise for subterranean termite control. Termite survival was significantly reduced within 7 days. After 28 days, all termites were dead in tests with imidacloprid, and only a few survived in tests with sulfluramid. Termites in the untreated controls fed significantly more on decayed blocks than on sound wood at all time intervals. Despite the termites' slight preference for treated decayed wood rather than treated sound wood, mortality ensued quickly after exposure to either substrate. This lack of dramatic difference in wood consumption and mortality suggests that the time consuming and labor-intensive process of decaying blocks is not justified for either bait toxicant at 100 ppm in wood. Despite low termite survival in the treatments, significant differences in block weight loss occurred over time. Wood degradation may have resulted from mould fungi emanating from the large numbers of dead and decaying termites associated with the treatments. This study also demonstrates the importance of correcting for wood weight loss attributable to experimental conditions, particularly when using decayed wood.