EFFECTS OF TEMPERATURE AND WIND-SPEED ON PINK-BOLLWORM (LEPIDOPTERA, GELECHIIDAE) MOTH CAPTURES DURING SPRING EMERGENCE

Numbers of pink bollworm moths, Pectinophora gossypiella (Saunders), captured daily in California's Pale Verde Valley during spring emergence were recorded in 6 data sets: 1985 emergence cages; 1986, 1987, and 1989 pheromone traps in cotton fields; and 1986 and 1989 valleywide pheromone survey traps. For 5 of the 6 data sets, numbers of moths were positively correlated with mean temperature for the interval 1800-2200 hours and minimum temperature for the interval 1800-0600 hours, and negatively correlated with mean wind speed for the interval 1800-2200 hours and the time at which wind speed fell below and stayed <2.7 m/s for the remainder of the night. Multiple regression was used to relate numbers of moths captured to these 4 weather variables. With nonsignificant variables deleted from each regression model, R(2) ranged from 0.86 to 0.96. Observations combined over data sets showed that numbers of moths captured were greatly reduced at temperatures < 18.1 degrees C, were reduced at intermediate temperatures only on windy nights, and were less affected by wind at temperatures > 22 degrees C. Although temperature and wind affect dispersion of the pheromone plume, there appears to be a direct effect on the moths themselves because regression model parameters were similar in nonpheromone-baited emergence cages and in pheromone traps.