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In trapping tests conducted in Israel cotton fields, propylure failed to show attractancy to male pink bollworm moths when used alone or in combination with deet, hexalure, antioxidant, or dodecyl acetate. A formulation of hexalure (and antioxidant) containing acetone was at least four times as attractive as one containing four times as much hexalure (and antioxidant) without acetone. Dodecyl acetate inhibited the response to hexalure, whereas linalyl acetate enhanced the response considerably.

Cis-7-Hexadecen-l-ol, the parent alcohol of hexalure, was found to be a powerful inhibitor of the attractant's potency. For maximum effectiveness hexalure should contain no more than 0.1% of the alcohol. A gas chromatographic procedure is described for determining the amount of the inhibitor in hexalure samples.

When hexalure was mixed with 5% by weight of N' -octyl- N -phenyl- p phenyenediamine the period of attractancy for male Pectinophora gossypiella (Saunders) moths was increased from 28 to 49 days, At all ages the potency of the 5%, formulations was equal to or better than that of neat hexalure. Field tests showed that larger proportions of antioxidant were even more beneficial, the optimum concentrations being 16-20% by weight. In addition to prolonging the period of effectiveness the inexpensive diluent makes use of the costly hexalure more economical.

A comparison of the field attractiveness of five samples of American-synthesized and one sample of Japanese-synthesized (Z,E)-9,11-tetradecadien-1-01 acetate (9,11-TDDA), the sex pheromone of Spodoptera littoralis Boisd. and S. litura (F.), showed that traps baited with one of the American-produced samples and the Japanese product were equally effective in attracting and capturing S. littoralis males in cotton and alfalfa fields of Israel. Optimum captures were obtained for periods up to three months with 4800 mug of 9,11-TDDA plus 8 mg of an antioxidant; higher doses were not advantageous. Paper squares were superior to two types of rubber septa and to closed polyethylene vials as dispensers for the pheromone; the polyethylene vials were least effective. In terms of numbers of moths captured, open polyethylene vials were as effective as paper dispensers when both were baited with 9-11-TDDA plus antioxidant. Admixture of (Z,E)-9,12-tetradecadien-1-o1 acetate (9,12-TDDA) with 9,11-TDDA was antagonistic at ratios of 1:20 and 1:50, but ratios from 1:500 to 1:1600 were synergistic, increasing moth catches up to 2.5-fold. Pheromone traps placed in Caesarea sand dunes located at least 3 km from the nearest host area captured larger numbers of males than traps placed in cultivated areas. It is therefore recommended that safety belts of pheromone traps, about 500 m apart, be used around cultivated areas to prevent invasion of the pest from outside and to attract males present inside such areas, thus reducing both the male population and mating through mass trapping and disruption of sex communication.

Gossyplure used to bait field traps at a dose of 50 micrograms admixed with 4–16 milligrams of an antioxidant attracted and captured male pink bollworm moths early in the cotton-growing season (early May) in Israel, whereas 20 milligrams of hexalure plus antioxidant was completely inactive under identical conditions. Although gossyplure without antioxidant was inactivated through decomposition within ten days, the mixtures remained attractive for at least two months; the antioxidant also increased moth catches 2.5 fold. Monitoring data obtained with 3000 gossyplure-baited traps, at one trap per 50 dunams2, in cotton fields in the Beth-Shaan region proved that capture thresholds of 5 moths/trap/night to the end of July and 8 moths/trap/night afterward were completely satisfactory for maintaining a low 2.8% average boll infestation for which only 5.8 insecticidal treatments were required during the entire growing season; results were even better in other areas of the country.

Four compounds previously identified as forming the pheromone complex of the female Spodoptera littoralis were tested alone and in combination for attraction to males in cotton and alfalfa fields. Only cis-9, trans-11- tetradecadienol acetate captured males when used to bait field traps, and admixture with the other three compounds showed no advantage. Combination of 16 micrograms of the attractant with 8–12 milligrams of a commercial antioxidant prolonged its attractive period from 48 hours to one month under natural conditions, but even 4 micrograms of the attractant was effective for a short period. The use of 0.1 or 1.0 milligram of the antioxidant was synergistic to the attractant, but the increased longevity imparted by higher concentrations makes the latter more efficient in survey and control programs for this serious pest.