EFFECTIVENESS OF A NEWLY DESIGNED SEX-PHEROMONE TRAP FOR THE SWEET-POTATO WEEVIL, CYLAS-FORMICARIUS (FABRICUS) (COLEOPTERA, BRENTIDAE)

A new funnel-based sex pheromone trap was designed for monitoring the sweetpotato weevil, Cylas formicarius (FABRICIUS), and its effectivene ss was compared with a funnel trap which has been used for monitoring thus far. Five traps of each type were alternately placed at 100 m int ervals along a straight road which was surrounded by fields of sugarca ne and sweet potato. A rubber dispenser containing 0.1 mg of the synth etic sex pheromone was used as an attractant During the study period, a total of 3,678 and 4,311 male weevils were caught in the new and ear lier version traps, respectively. No significant difference was found between the two trap types in the number of weevils caught. Both types of traps also collected other arthropods. The new traps caught 17 ind ividuals, while 286 were caught in the earlier type traps. The latter traps captured significantly more superfluous arthropods than the new traps.