Abstract
Research was conducted to quantify volatile compounds emanating from the flower buds of seven cotton (Gossypium hirsutum L. ) cultivars at two planting location, to determine the influence of the volatiles on boll weevil behavior and pheromone production. Volatiles were collected on Porapak Q from the air surrounding the flower buds, and consisted mainly of the monoterpenes: [alpha]-pinene, β-pinene, β-myrcene, d-limonene and β-ocimene. The concentrations of monoterpenes were significantly greater from the glanded than from the glandless cultivars Differences in monoterpene concentrations were also observed among the glanded cultivars. Behavioral responses of the boil weevil (Anthonomus grandis grandis Boheman) to olfactory stimuli were determined in bioassays utilizing a multichambered pedestrian olfactometer. The boll weevil was significantly more attracted to flower buds of 'SP-37' were significantly more attractive than those of 'CAMD-E' when cultivated at Corpus Christi, Texas. The reverse was found for these cultivars grown at College Station, Texas. Males were observed to be more responsive to flower buds than females. Boll weevils were attracted to 0.45 ng of a synthetic formulation of monoterpenes representing the ratio of monoterpenes found in LEBO flower buds. Pheromone production during the first 2 wk of adulthood from boll weevils fed on 'CAMD-E' flower buds increased rapidly from day six to day 13. The ratios of the pheromone components (I) (+)-cis-2-isopropenyl-1-methyl-cyclobutaneethano, (II) cis-3,3-dimethyl- Δ^[1-β]-cyclohexaneethanol, (III) cis-3,3-dimethyl- Δ^[1-[alpha]]-cyclohexaneacetaldehyde, and (IV) trans-3,3-dimethyl- Δ^[1-[alpha]]-cyclohexaneacetaldehyde changed through time. The largest ratio for the aldehyde components (III and IV) compared to the alcohol components (I and II) occurred on day 13, with the ratio of 2.9:2.7:1.0:1.0, for components I to IV respectively. A greater amount of pheromone was produced when boll weevils were fed flower buds of the five glanded than the two glandless cottons. The location where the cultivar was grown affected boll weevil pheromone production for some cultivars. Significantly more pheromone was produced by boll weevils fed on 'SP-37' grown at Corpus Christi than for the other six cultivars...
Chang, Juan Felix Fong (1986). Influence of cotton cultivars on boll weevil (Coleoptera: Curculionidae) behavior and pheromone production. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -24015.