Response of Catolaccus hunteri (Hymenoptera: Pteromalidae) to Colored Sticky Traps in the Laboratory

Catolaccus hunteri Crawford (Hymenoptera: Pteromalidae) is the most abundant parasitoid attacking the pepper weevil, Anthonomus eugenii Cano, in Florida (Riley & Schuster 1992). The parasitioid was also recovered from weevil infested fruit collected in several states in Mexico and other countries in Mesoamerica (Aguilar & Servin 2000; Mariscal et al. 1998). While natural enemies generally are regarded as contributing little for the control of the pepper weevil (Elmore & Campbell 1954), augmentative releases of C. hunteri on the alternative host plant American black nightshade during the off-season and on pepper at the initiation of flowering have resulted in reduced or delayed damage by weevil larvae (Schuster 2007). The pepper weevil is a serious economic pest of cultivated Capsicum spp. peppers in the southern United States (Elmore et al. 1934; Goff and Wilson 1937; Riley & King 1994), Mexico (Laborde & Pozo 1984), Central America (Andrews et al. 1986), and the Caribbean (Abreu & Cruz 1985). The pest was found in field trials to respond to yellow sticky traps (Riley & Schuster 1994). Pheromone baited, yellow sticky traps (Trece Inc. Adair, Oklahoma) are used to monitor migration of pepper weevil adults into pepper fields and to time the applications of insecticides targeting weevil adults (Natwick & Trumble 2007). It is not known whether C. hunteri also responds to yellow sticky traps and whether the traps might be useful for monitoring the activity of the parasitoid. The purpose of the present investigation was to evaluate the response of C. hunteri in the laboratory to sticky traps of selected colors. The C. hunteri adults used in the experiment were obtained from a laboratory colony maintained on a factitious host, Callosobruchus maculatus Fabricius (Coleoptera: Bruchidae), on garbanzo beans (Cicer arietinum L.) (Vasquez et al. 2005). Experiments were conducted in a room maintained about 27 °C, about 60% RH and 14:10 h L:D. Yellow, white, red, blue, gray and green plastic sheets were cut into 10.2 cm squares that were coated on one side with Tanglefoot® Tangle-TrapTM Insect Trap Coating Brushable (The Tanglefoot Co., Grand Rapids, Michigan). The Tangle-Trap was heated to 87 °C and, when it turned from translucent to clear, was spread into a thin layer on each square with a 1.3 cm paint brush. Single squares of each color were randomly placed horizontally in a circular pattern on the bottoms of 12, 70 cm × 70 cm × 70 cm screen cages. About 200 female C. hunteri adults of unknown age were released in the middle of the ring of plastic squares in each cage and the numbers trapped were determined 24 h later. Data were subjected to analysis of variance and, when an F value was significant at P < 0.05, means were compared using the Least Significant Difference (SAS Institute 2008). On average, only about 25% of the C. hunteri adults released into the cages were trapped on the colored, plastic squares coated with adhesive (Table 1). Of those captured, about 3 times more were trapped on yellow, red or white squares than were trapped on green, blue or gray squares. The yellow sticky traps used for monitoring the presence/abundance of pepper weevil adults in the field may also be useful in detecting the presence of adult C. hunteri females.