Temporal and age-related variations in calling and mating patterns of the Indian population of spotted pod borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae)

Abstract

Maruca vitrata is an important pantropical and polyphagous insect pest of grain legumes. The adult emergence pattern and temporal variations in the calling and mating behaviour of M. vitrata across ages were studied. Observations revealed that adult emergence was not influenced significantly by sex, but by the time of the day. Calling activity is a strong determinant of male mating success in insects. An age-dependent female calling pattern was observed. Females seldom called on their day of emergence, calling percentage was low to nil in the first four hours of scotophase but reached a peak in the fifth hour. The calling patterns of females of different ages were similar except that there were two peaks of calling for 3 and 4 days old females. Like calling, the mating pattern was also age-dependent, i.e. M. vitrata mating frequency was maximum at 3-days of age and thereafter decreased gradually with age. The highest mating frequency (30.83%) was observed at 2200 h for 3-day-old moths. The current study revealed that age dependant and distinct patterns in female calling, synchronous male responsiveness leading to mating in M. vitrata. The output of the study could be utilized in various aspects of M. vitrata semiochemical based research.