Unreceptivity – a phenomenon induced by male accessory gland secretions in female Helicoverpa armigera

Abstract

Unreceptivity, a phenomenon generally observed in female insects following mating, was investigated by simulating a mating situation in Helicoverpa armigera females by injecting male accessory glands and duplex (MAG-duplex) extracts sans sperm. Injection of extracts into the abdomen of virgin females induced unreceptivity. The virgin females started behaving like mated females by rejecting the males by avoiding the advances made by the latter to mate. Unreceptivity was observed in about 93% of the females on the day of injection, which reduced to 82% on the second scotophase compared to controls. However, on the third day, 75% of them reverted back to receptivity that was comparable to virgin count. The Tricine–SDS-PAGE of MAG-duplex of virgin and mated male moths revealed the conspicuous absence of a low molecular weight (< 7 kDa) peptide band in the mated moths, and the possibility of being delivered to female at the time of mating. MALDI-TOF spectra of the same extracts showed the presence of several peptides < 7 kDa, further, the absence of them in mated moths.