Cotton Yields as Affected by Pheromone Treatments for Pink Bollworm

Cotton fields treated with Gossyplure pheromone for pink bollworm, Pectinophora gossypiella (Saunders), management were surveyed to evaluate the effectiveness of the pheromone treatments. Fields were randomly chosen within four separate areas of the Parker Valley and Palo Verde Valley and sampled weekly for presence of pink bollworm (PBW ) larvae. No differences were found in cotton yields between fields treated with pheromone and nontreated fields. Introduction Pink bollworm (PBW) has become one of the major insect pests threatening cotton production in Arizona. Control of PBW is best accomplished with a combination of cultural and chemical control (Brown, Huber, and Moore, 1990). Gossyplure PBW sex pheromone has been determined to be a good tool for monitoring of male moth populations (Chu and Henneberry, 1990), and has been used to disrupt mating of PBW moths. In the growing season of 1990, a PBW pheromone program was implemented in the Parker Valley area of Arizona. Gossyplure PBW pheromone was applied to 25,000 acres planted to Upland cotton. To create an independent survey of this program, the University of Arizona sampled fields throughout the Parker Valley and Palo Verde Valley of California. Fields in the Palo Verde Valley were used as control checks as they were not treated with pheromone, but would likely have similar insect pressures and growing conditions. Materials and Methods Upland cotton fields were selected randomly, but fell under the criteria of having 20 acres or more and planted early in the season. Within the Parker Valley, three areas were identified (I, 1I, 111) and another in the Palo Verde Valley (IV). Area I represented the northern third of the valley, area ll represented the middle third, and area IH represented the southern third. Area IV was used as a non treated check area. Gossyplure PBW pheromone was applied in Mitsubishi rope formulation on 10,000 acres, and in aerial fiber applications on 15,000 acres. Four rope and fiber fields were identified in each area and sampled weekly for existence of PBW larvae and secondary pests. In addition, four later planted fields were sampled in area H. Samples were taken in each of four quadrants within a single field. Within each quadrant, insects were sampled with use of a sweep net. Leaves and plant terminals of 25 plants in each quadrant were examined for insect eggs, larvae, and feeding damage. In addition, 25 bolls were inspected for PBW larval presence. These tests were repeated in each corner of the field being sure to stay away from edges to assure accuracy of sampling.