Pyramidal Traps for Monitoring the Presence of Pecan Weevil (Coleoptera: Curculionidae)

Abstract

Pyramidal traps constructed of masonite and painted to reflect light levels ranging from 1 to 84% reflectance (black, shades of gray and white) were evaluated for attractiveness to adult pecan weevils, Curculio caryae (Horn). Black (1% reflectance) and dark gray (5% reflectance) were found to be more attractive to weevils than traps having greater reflectance (lighter grays and white). Dark gray traps captured almost 9 fold more weevils than did standard cone emergence traps. Dark gray traps also captured weevils in orchards after the emergence period as indicated by screen cone traps. Trap distances of 1.9 and 4.6 m from tree trunks did not influence trap effectiveness. Trap density of 4/tree did not provide an economic level of weevil control as measured by number of infested nuts per tree. Traps positioned on the eastern side of trees caught more weevils (α ≤ 0.05) than traps on the northern side, but captures were not significantly different from those positioned at the southern and western sides of trees.