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The full-complement pheromone of Heliothis zea (Boddie) females, pheromone components, and component combination were evaluated as mating disruptants at selected application rates and moth population densities. Pheromone components were evaporated from point sources at the rate of 100 point sources per screen field cage (9 by 30 m) (3,700/ha) planted with cotton, Gossypium hirsutum L. Treatment efficacy was determined by observing and comparing the numbers of mating pairs (laboratory-reared moths) within the cages. The full-complement pheromone was most effective at the lowest moth population density. The highest application rate tested (370g/ha) was more effective than lower rates.

The production of the 4 monoterpene compounds that comprise the pheromone of Anthonomus grandis Boheman (I, (+)- cis -2-isopropenyl-1-methylcyclobutaneethanol; II, ( Z )-3,3-dimethyl-δ1, B-cyclohexaneethanol; III, ( Z )-3,3-dimethyl-δ1, a,-cyclohexaneacetaldehyde; and IV, ( E )-3,3-dimethyl-δ1, a-cyclohexaneacetaldehyde) was determined from amounts in the feces of male weevils fed diets with and without chemosterilants. Cotton buds, the natural food source of the insect, promoted a higher level of pheromone biosynthesis by the insects than did the laboratory diet, mostly because weevils fed the laboratory diet produced lesser amounts of the aldehydes (III and IV). Insects fed apholate or busulfan produced markedly less of the alcohols (I and II) compared with insects fed cotton buds or diet without chemosterilants. Furthermore, the chemosterilants caused a proportional decrease in the formation of II relative to I and III.

A series of substandard diets modified from the regular pinto bean diet of Spodoptera frugiperda (J. E. Smith) were evaluated as bioassay candidates to be used in plant resistance phytochemical investigations. Larvae that were fed different concentrations of centipedegrass mixed in the regular pinto bean diet or the regular pinto bean diet without Torula yeast weighed significantly less than those fed on the same diets with similar concentrations of bermudagrass. Pinto bean diet without yeast plus bermudagrass was the only diet that produced an increase in larval weights with each increase in the amount of plant material added. As little as 2 g of centipedegrass per diet significantly inhibited larval growth. Larvae produced on the corn-soy flour-milk solids-based diet without yeast plus the grasses weighed significantly more than those produced on the pinto bean diet without yeast plus the grasses. The pinto bean diet containing either centipede or bermudagrass but without yeast produced larvae with weight differences large enough to separate the resistant and susceptible plant materials. Based on the evidence described here, two diets would be acceptable: the regular pinto bean diet or the substandard pinto bean diet without the yeast. We chose the substandard pinto bean diet without the Torula yeast as a bioassay vehicle for our future phytochemical investigations.

Both sexes of Anthonomus grandis Boheman responded in the field to a synthetic pheromone mixture, grandlure. A wick-type formulation of grandlure containing glycerol, water, polyethylene glycol, and methanol was over 80% competitive as an attractant for 7 days with caged, live males fed cotton squares (flower buds) once or twice a week.

Solvent extracts from larvae and adults of Anthonomus grandis Boheman produced numerous morphological changes when they were applied topically (1–100 µg/insect) to larvae and pupae; egg hatch also was decreased. The extracts possessed a potency (ED50 = 1–25 µg/insect) comparable to that of synthetic cecropia juvenile hormone (a mixture of isomers). Larval development was arrested for 3–4 weeks when larvae were treated with the acetone and petroleum ether extracts.

The air-space volatiles present in the Robert T. Gast Rearing Laboratory at Mississippi State, Miss., were determined by pulling an air stream through a porous polymer, desorbing the volatiles with pentane, and analyzing them by GLC-MS. The volatiles from the diet, the diet wax, and the insects ( Anthonomus grandis Boheman) were similarly analyzed in an attempt to identify the sources of the volatiles in the air space. A total of 168 compounds was identified from these sources including 35 aliphatic hydrocarbons, 30 aliphatic alcohols, 26 aliphatic carbonyl compounds, 23 aromatic hydrocarbons. 13 aromatic carbonyl compounds. 7 phenols and cresols, 7 gamma -lactones, 6 ethers and furans, 5 aromatic alcohols, 5 heterocyclic compounds, 8 phthalates, and 3 other esters. The low molecular weight alcohols, carbonyl compounds, esters, and a pyrazine present chiefly in the diet volatiles were attributed to microbial contamination. The gamma -lactones were believed derived during the cooking of the diet, and most of the n -alkyl hydrocarbons were derived from the diet wax. The facility mechanical plant was presumably the source of a number of aromatic hydrocarbons that are typical trace constituents of industrial oils. Small amounts of the pheromone alcohols present in boll weevils were found in the rearing facility air-space, but none were found in the insects themselves.

Analytical procedures were developed to determine whether the antimicrobial agents methy1- p -hydroxybenzoate and potassium sorbate had been constituted properly in 2 diets for larvae of Anthonomus grandis Boheman and whether they were stable to the heat provided by autoclaving or flash sterilizing, to pH 5.5, to other dietary constituents, and to continued dispersal in the diet at room temperature for 2 weeks. Both TLC-UV and GLC procedures gave average recoveries above 95%. Thus, no degradation problems were evident. These agents are used to preserve foodstuffs from molds, yeasts, and bacteria.

Plant resistance was demonstrated in common centipedegrass, Eremochola ophiuroides (Munro) Hack., to Spodoptera frugiperda (J. E. Smith). Both antibiosis and nonpreference mechanisms of resistance were found when compared with bermudagrass, Cynodon dactylon (L.) Pers., and carpetgrass, Axonopus affinis Chase. Larval mortality at 9 days was as high as 50% on centipedegrass in the forced-feeding tests. Fall armyworm larvae preferred carpetgrass or bermudagrass by as much as 6 to 1 over centipedegrass. Results also indicated that, if larvae were produced on a susceptible host in a mixed stand of centipedegrass, some of the larger fall armyworms could possibly survive, but a strong antiobiotic response would remain and thus affect larval growth.

The production of pheromone by Anthonomus grandis Boheman when treated with 10,000 rad of $sup 60$Co gamma irradiation compared favorably with that of control weevils for 5 days; however, feeding (determined by frass collection) was reduced from day one. No direct correlation was found between production of pheromone and elimination of frass. (auth)

The mineral content of Anthonomus grandis Boheman, wild and mass-reared, cotton buds, and synthetic diets was determined by atomic absorption spectrophotometry. Manganese was low by a factor of 10 in the artificial diet when compared to cotton squares. All minerals except copper were enhanced, especially iron (100-fold) in overwintered weevils when compared to F1 weevils.

Bioassay results with 37 terpenoids and related plant constituents indicate that linalool oxide, geranyl acetate, neryl acetate, rose oxide, fenchone, menthone, isovaleraldehyde, and linalool were among the most attractive to Anthonomus grandis Boheman. Three 4–6 component mixtures were nearly as attractive as extracts of cotton buds.

An experimental slow-release formulation of grandlure, the synthesized pheromone of the male of Anthonomus grandis Boheman, proved to be 90–100% as effective in the field as male weevils when the weevils and the formulation were tested in the field for 7 days or longer. The formulation was superior to formulations used previously and was used effectively in traps for survey and research and in the Pilot Boll Weevil Eradication Experiment in S Mississippi.

When the essential oils of several host and nonhost species within the Malvaceae family and some angiosperms and gymnosperms were tested for attractancy to Anthonomus grandis Boheman, the oils were as attractive as cotton oil. Moreover, the insect actually favored essential oils of 2 alternate host plants, Hibiscus Militaris Cav. and H. lasiocarpus Cav., in comparative preference tests with cotton oil. Thus, in the laboratory, the essential oils in plants did not control insect preference exclusively. Morphological and environmental conditions may influence the concentrations of volatile components released by the plants to the atmosphere.

When isolated free fatty acids (FFA) and methyl ester fatty acids (MEFA) from larvae of A nthonomus grandis Boheman were applied topically to larvae and pupae, juvenile hormonelike characters such as retardation, arrest, formation of intermediates, and deformities occurred. Effective doses of both standard and isolated unsaturated FFA and MEFA were (ED50) 25–30µg for larvae and 15–20 µg for pupae. The FFA in larvae does not exceed 9 µg. The endogenous FFA levels drop significantly during larval development, reaching a minimum just before the onset of pupation.