Species composition and flight pattern of xyleborini ambrosia beetles (Col.: Curculionidae: Scolytinae) from agricultural areas in Southern Thailand

Abstract

Ambrosia beetles are normally defined as a secondary insect pest; in recent decades however, some species of beetles have become pestiferous, invading living trees and causing enormous damage to both indigenous and exotic species. However, ecological studies of these beetles in agricultural and native forests are lacking. In the current study we address the species diversity and the seasonal flight pattern of Xyleborini ambrosia beetles found in fruit orchards. Beetles were collected with ethanol baited panel traps in 20 durian orchards in southern Thailand throughout 15 mo. In total, 15,444 xyleborine ambrosia beetles representing 64 species (21 genera) were captured. Of these 64 species, 12 had not been recorded previously in Thailand. In this relatively homogenous habitat, only a few species were frequently captured. The species diversity and mean abundance per trap were not significantly different among cropping systems and study zones. However, the mean abundance per trap was significantly different between the dry and rainy seasons (t = 9.497; df = 12; P = 0.001). The flight pattern of xyleborine ambrosia beetles in the perennial fruit community fluctuated seasonally with the highest abundance in the middle of the rainy season continuing into the early summer and low abundance occurring in the remaining months. A linear regression analysis indicated that temperature and relative humidity predicted the flight pattern and that the climatic variables in the two previous months have a higher predictive power of the number of beetles than the variables in the month being investigated. © 2012 Entomological Society of America.