OPTIMIZATION OF SEMIOCHEMICAL-BASED TRAPPING OF METAMASIUS-HEMIPTERUSSERICEUS (OLIVIER) (COLEOPTERA, CURCULIONIDAE)

Response of adults of the West Indian sugarcane weevil, Metamasius hem ipterus sericeus, to various semiochemical treatments and physical tra p designs was studied in southern Florida in field-grown banana and Ca nary Island date palms. Ethyl acetate released alone at 860-1007 mg/da y was as effective for the capture of M. h. sericeus as a combination of ethyl acetate (844-919 mg/day), ethyl propionate (348-362 mg/day), and ethyl butyrate (117-137 mg/day) and in one trial was more effectiv e than fermenting sugarcane (250 g), ethyl propionate alone (353-384 m g/day), ethyl butyrate alone (123-174 mg/day), or no treatment. Ethyl acetate released alone at 675-683 mg/day was as attractive as 250 g of fermenting sugarcane or the racemic blend of the male-produced aggreg ation pheromones [(+/-)-5-methyl-nonan-4-ol and (+/-)-2-methyl-heptan- 4-ol (8:1 ratio) ''metalure''] at 3 mg/day. Weevil counts increased wi th binary combinations of ethyl acetate, sugarcane, and/or metalure ov er these treatments alone and the ternary combination was two to three times more effective than any of the binary treatments. Attraction to ethyl acetate released alone at 777 mg/day with metalure was greater than to the hydrolysis products of ethyl acetate (ethanol and/or aceti c acid each released at about 6-8 mg/day) with metalure. Weevil counts from traps baited with 250 g of sugarcane and metalure increased with increasing dose of ethyl acetate to about 400 mg/day and then appeare d to plateau. Ethyl acetate (about 700 mg/day) and metalure increased weevil counts in traps with increasing amounts of sugarcane (0-2 kg). Molasses (45 g) + water (158 ml) substitutes for sugarcane were about as effective for capturing M. h. sericeus as 250 g of fermenting sugar cane [all treatments with ethyl acetate (847 mg/day) and metalure]. Ea rly experiments used a lethal pitfall trap. We demonstrated that sever al alternative trap designs were more effective than the lethal pitfal l trap for capturing weevils. Color and height (on ground vs. 1 m on p ole) did not affect trap efficacy when baited with the ternary combina tion of ethyl acetate (672-825 mg/day), sugarcane (250 g), and metalur e.