Inheritance of a temperature-modified phenotype of the short antennae (sa) mutation in a moth, Ephestia kuehniella (Lepidoptera: Pyralidae)

Abstract

The autosomal recessive mutation short antennae (sa) causes considerable shortening of antennae in male and female Mediterranean flour moths (Ephestia kuehniella Zeller). However, the sa phenotype can be suppressed by several physical factors, making sa moths indistinguishable from wild-type moths (saWT). This can be done by subjecting larva and pupa to a higher temperature (25°C), to lithium ions, or to an alternate electric field. The first half of pupal development was found to be the sensitive period for the saWT phenotype. The saWT phenotype is stable and cannot be reverted to the original sa type by physical or chemical factors. The saWT phenotype is transmitted to future generations. When crossed with typical sa moths, the saWT phenotype is inherited either as a dominant character if carried by males or a semidominant character if carried by females. We compared proteins of the ejaculate, accessory gland secretions, and spermatophore in sa, saWT, and wild-type males and found considerable differences between sperm proteins of saWT, sa, and wild-type males. The saWT phenotype influences the mating success of males: saWT males mated successfully with any females, whereas typical sa males were less successful in mating and then mainly with females of the same phenotype.