Variation in and Heritability of Aspects of Pheromone Production in the Pink Bollworm Moth, Pectinophora gossypiella (Lepidoptera: Gelechiidae)

Abstract

The genetic basis of variation in pheromone production by pink bollworm moths, Pectinophora gossypiella (Saunders), was examined by GLC analysis of pheromone gland extracts from females in a laboratory colony. The genetic correlation between the amounts of the two pheromone components, ( Z,E )- and ( Z,Z )-isomers of 7,11-hexadecadienyl acetate, was 0.99, suggesting that genetic factors controlling their production are identical or closely linked. The mean percentage of the ( Z,E )-isomer was 44.2%. The limited variation found in component blends (CV = 5.3%) may reflect the importance of low signal variability for efficient communication. Heritability of total amount of pheromone in the gland was 0.41, and heritability of pheromone blend was 0.34. One generation of inbreeding had no detectable effect on pheromone blend, but total pheromone production was decreased by 26%. Mean component blends produced by females in a laboratory strain and in a strain incorporating recently collected wild males were not significantly different, but the amount of pheromone was significantly lower in the laboratory colony.