Monitoring seasonal population fluctuation of spotted and spiny bollworms by synthetic sex pheromones and its relationships to boll infestation in cotton¹

Abstract

Experiments were conducted to monitor the seasonal population fluctuation of spotted bollworm, Earias vittella (F.) and spiny bollworm, E. instrlana (Boisd.) (Lep., Noctuidae) by synthetic sex pheromone traps and relationship between moth catches and larval infestation in bolls of cotton. The traps were baited with 1 mg of sex pheromone (10E,12E)-10,12-hexadecadienal; and 10:2 mixture of (10E,12E)-10,12-hexadecadienal and (Z)-11-hexadecenal for spiny and spotted bollworms respectively. The daily catches of spotted and spiny bollworm moths were variable, however, avera e number of moths captured in pheromone baited tra s were also positively correlated with the number of larvae per plant. The larval population in the Ruiting bodies of cotton and the moth counts in pheromone traps increased with the developmental stages of the crop. The eak moth population and larval infestation of spotted and spiny bollworms was observed in the montts of August and October respectively. Results indicated that a mean trap catches of 9-12 moths per night of spotted bollworm was associated with economic injury level of infestation. Although, a maximum of 12 moths er trap per night in the month of October were captured in case of spiny bollworm but the inLstation remained below economic threshold i.e. 10 % damage. catches per night were positively correlated with the larval infestation in cotton bolls. Average night K y 1974: Insecticide applications based on hexalure trap catches versus automatic schedule treatments for pink bollworm moth control. J. Econ. Entomol. 67, 522-524.

SEASONAL FLUCTUATION OF THE SPINY BOLLWORM, Earias insulana (BOISD.) ON SOME HOST PLANTS

“…The attack on the cotton bolls is generally higher than buds. Highest infestation was recorded during August and September (Qureshi & Ahmed, 1991).…”

“…increased slowly until to mid-September and rapidly there after. Qureshi and Ahmed (1991) the larval population in the fruiting bodies of cotton and the moth counts in pheromone traps increased with the developmental stages of the crop. The peak of moth and larval infestation of spotted and spiny bollworms was observed in August and October, respectively.…”