FLIGHT ACTIVITY OF PROSTEPHANUS-TRUNCATUS (HORN) (COLEOPTERA, BOSTRICHIDAE) IN RELATION TO POPULATION-DENSITY, RESOURCE QUALITY, AGE, AND SEX

Higher flight activity has been observed in aged, high-density culture s of Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), but adu lts in new, low-density culture jars showed less flight activity. In o rder to understand this change in behavior, the effects of population density, age,resource quality, and sex on the flight of P. truncatus w ere studied in a wind tunnel. While an immediate density on the releas e platform had no significant effect on Fight, beetles from high-densi ty cultures were more inclined to fly than those from low-density cult ures. Resource quality exerted a major influence on Fight; insects in food suitable for boring and oviposition seldomly exhibited Fight, how ever, when food was absent or of inferior quality for boring and ovipo sition, the dominant behavior was flight. Also, insects maintained for a week in food suitable for boring and oviposition were less ready to Fy than those maintained in food unsuitable for boring and ovipositio n. The optimum age range for flight activity was before the peak of re production and insects rarely Few before 4 days or after 32 days of em ergence. There were no significant differences between the flight acti vity of males and that of females. Based on these results, we conclude that age and resource quality are major influences on the flight acti vity of P. truncatus and a hypothesis is proposed in which reproductiv ely active male and female beetles disperse from habitats of low resou rce quality to those that support their reproductive behavior, The pra ctical implications of these results and the possible role of the male -produced aggregation pheromone are discussed.