Weevil Cotton boll, Anthonomus grandis

Scheme 54 summarizes Font s synthesis of (+)-grandisol (36), the male pheromone of the cotton boll weevil (Anthonomus grandis) [80]. The key-step is the double [2+2] photocycloaddition of ethylene to bis(a,(3-butenohde) A to give B, which yielded C after glycol cleavage. The recently identified pheromone of the oleander scale (Aspidiotus nerii) possesses a structure similar to that of grandisol (Scheme 54), and its synthesis was reported by Ducrot [81 ] and also by Guerrero [82,83]. 

The number one cotton pest in the United States, the boll weevil (Anthonomus grandis Boh.), occurs in Mexico, Costa Rica, Nicaragua, Colombia, and Venezuela and is probably also the number one pest in these countries. 

For example, gossypol, a terpenoid substance, is an allomone that limits herbivory by several lepidopteran species on cotton (Gossypium spp., MalvaceaeK whereas it is a kairomone for the boll weevil, Anthonomus grandis and acts as a feeding stimulant for this insect (3,21,22) ... 

Curculionidae. The boll weevil, Anthonomus grandis, that great despoiler of cotton in the southern U. S., synthesizes a quaternary blend of sex pheromones that have been collectively labeled grandlure. Four compounds that interact synergistically have been identified as (+)-2-(cis-isopropenyl-1-methylcyclobutyl) ethanol (XI), (Z)-2-(3,3-dimethyl cyclohexylidene)ethanol (XII), (Z.)-2-(3,3-dimethylecyclohexylidene)acetaldehyde (XIII), and (Ej-2-(3,3-dimethylcycloh.exylidene)acetaldehyde (XIV) (54). 

Graiidisol Cotton boll weevils Anthonomus grandis) Ms Intramolecular diastereoselectiv c alkylation of a-benxencsulfonyi-y-lactones [198J... 

Relatively high concentrations of boron compounds are used to control fmit flies, cockroaches, gypsy moth larvae, houseflies, and woodboring insects. Boric acid is an effective stomach poison for several insect species, including German cockroaches Blattella germanica), that are unable to detect the presence of boric acid. Insect infestation of wood and other substrates can be prevented by pretreatment with boric acid or borax at doses of 0.25-0.55 kg/m of wood. Boric acid and other boron compounds are effective chemosterilants of the cotton boll weevil (Anthonomus grandis) and houseflies. 

The male cotton boll weevil (Anthonomus grandis) is attracted to the cotton plant by a number of monoterpenes and sesquiterpenes, among them are a-pinene (14), limonene... 

Attempts have been made to isolate and identify the dominant chemicals responsible for feeding specificity of a number of insect herbivores. An extensive effort for the cotton boll weevil, Anthonomus grandis, led to the conclusion that there were no dominant compounds in this case (Temple et al., 1968). On the contrary, these workers concluded that full feeding responses probably require a complicated profile of components. Few active components were identified because of the difficulties with reformulating active mixtures. 

The males of the cotton boll weevil Anthonomus grandis, Coleoptera, Plate 6), a serious pest of cotton, produce a sex pheromone to attract females. The pheromone, known as grandlure, consists of a mixture of at least four monoterpenes (Figure 6.7). The males make these compounds from geraniol and nerol (the cw-isomer of geraniol), present in the cotton buds on which they feed. 

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