AGGREGATION PHEROMONES AND HOST KAIROMONES OF WEST-INDIAN SUGARCANE WEEVIL, METAMASIUS-HEMIPTERUS-SERICEUS

Coupled gas chromatagraphic-electroantennographic detection (GC-EAD) a nalyses and coupled CC-mass spectrometry (MS) of volatiles produced by male and female West Indian sugarcane weevils (WISW), Metamasius hemi pterus sericeus (Oliv.), revealed eight male specific, EAD-active comp ounds: 3-pentanol (1), 2-methyl-4-heptanol (2), 2-methyl-4-octanol (3) , 4-methyl-5-nonanol (4), and the corresponding ketones. In field expe riments in Florida, alcohols 1-4 in combination with sugarcane were mo st attractive, whereas addition of the ketones or replacement of alcoh ols with ketones significantly reduced attraction. In Costa Rica field experiments testing alcohols 1-4 singly and in all binary, ternary, a nd quaternary combinations revealed 4 in combination with 2 was the ma jor aggregation pheromone, equally attracting male and female WISW. St ereoisomeric 4 and (4S,5S)-4, the only isomer produced by WISW, were e qually attractive. Addition of 4S-, 4R- or (+/-)-2 to (4S,5S)-4 signif icantly enhanced attraction. Sugarcane stalks in combination with 2 pl us 4 (ratio of 1:8) were highly synergistic, whereas EAD-active sugarc ane volatiles ethyl acetate, ethyl propionate, or ethyl butyrate only moderately increased attractiveness of the pheromone lure.