The banana root borer Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) is a major pest of bananas throughout the world. Chemical control is both undesirable and expensive, where biological control alternatives are limited, and pheromone-based trapping results in low captures. In this study, several important factors that affect pheromone-based catches, such as trap type, trap dimensions, and color and position of the traps, were optimized. Ground traps were found to be superior to ramp and pitfall traps, and larger traps (40 x 25 cm and above) were more efficient than smaller ones (30 x 15 cm). In a color-choice test, the banana weevil clearly preferred brown traps over yellow, red, gray, blue, black, white, and green, with mahogany being more attractive than other shades of brown. In addition, pheromone baited ground traps positioned in the shade of the canopy caught significantly more adults than those placed in sunlight. Therefore, mahogany-brown ground traps 40 x 25 cm appear to be the most efficient at catching C. sordidus adults and have the greatest potential for use in mass trapping and programs for eradication of this pest.

Aggregation pheromone of the Australian population of New Guinea sugarcane weevil, Rhabdoscelus obscurus (Boisduval), in conjunction with other semiochemicals, was used to develop an efficient trapping method for the weevil population in Guam. In a field experiment at Yigo, plastic bucket traps baited with the lure of the Australian R. obscurus population in combination with ethyl acetate and cut sugarcane captured significantly more weevils than traps baited with pheromone + ethyl acetate, pheromone + sugarcane or individual lure components alone. Traps baited with various semiochemical-based lures and treated with insecticide captured significantly greater numbers of weevils than those not treated with insecticide. Traps baited with cut sugarcane caught significantly more weevils than those without sugarcane. Semiochemical-based trapping in weevil management has potential either in mass trapping or as part of an integrated pest management (IPM) programme. Based on the present findings, a future line of work for the control of this weevil is proposed.

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.

Within Curculionoidea, high numbers of gall inducers exist only in Ceurthorhynchinae, Baridinae, and Curculioninae (Korotyaev et al. 2005). Several species of Curculioninae are well-known gall inducers on plants belonging to Asteraceae and Caryophyllaceae (Anderson 1962; Kaplin 1981; Dieckmann 1988). Currently only five species of gall-inducing Baridinae are known, including Acythopeus burkhartorum O'Brien, 1998 (Table 1). Gall-inducing