Abstract:The banana root borer Cosmopolites sordidus (Coleoptera: Curculionidae) is native to Malaysia and Indonesia but is found in nearly all banana-growing areas of the world. Studies were conducted to determine the pheromone trap efficacy, effect of shade on trap catches and to monitor the population of C. sordidus using pheromones in Guam. In Guam, pheromone traps were used to monitor the population level of C. sordidus. Before monitoring began, two basic studies were carried out, which established that pheromone-baited ramp traps positioned in the shade of the banana crop canopy caught significantly more adults than those placed in sunlight and that ramp traps baited with pheromone lures caught significantly more adults than did identical traps without pheromone lures. Ramp traps baited with pheromone lures were set up at each of 10 locations throughout the island in November 2005. Weekly counts were made of the borers caught by the pheromone traps.The data indicated higher population levels (>10 per week) in the northern region and low (<5 per week) to medium level (5-10 week) populations in the southern part of the island. These differences among sites were highly significant. Linear and quadratic effects of rainfall on the number of borers captured were statistically significant, but according to quadratic regression models, the significance was due to differences at just one site.

The mealybug Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae), attacks ornamental and fruit crops in the Mariana Islands. Insecticides cannot penetrate the heavy layers of wax that protect the insect's body. We surveyed the mealybug's locally recruited natural enemies and their effects on its population on Guam, Rota, Saipan, and Tinian to assess the need for introduction of exotic natural enemies. We monitored population densities of M. hirsutus, those of its natural enemies, and parasitism rates for 3 yr, 2005-2007. Our surveys revealed the presence of two parasitoids, Anagyrus kamali Moursi (Hymenoptera: Encyrtidae) and Allotropa sp. near mecrida (Walker) (Hymenoptera: Platygastridae), fortuitously introduced to the Mariana Islands with M. hirsutus. The predator Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) also was often found feeding on M. hirsutus. Population density of M. hirsutus was below the economic threshold at all locations. Rainfall seemed to affect mean numbers of M. hirsutus and mean numbers of eggs at some locations. On all four islands, the two parasitoids, complemented by the predator, were effectively controlling the M. hirsutus population. No evidence of hyperparasitism was recorded. Currently, economic damage by M. hirsutus is not a concern in the Mariana Islands, and additional parasitoids need not be introduced to control M. hirsutus.