Aspects Of The Mating Behaviour Of Glossina Morsitans Westwood And Gloss Ina Pallidipes Austen

Abstract

sexual receptivity was investigated in glossing morsitans orsitans and glossing pallidipes by observing successful pairings of females for specified periods of time .the duration of copulation, degree of insemination of females and male accessory reproductive gland secretions were not responsible for the termination of sexual receptivi ty in aorsitans. however, mechanical stimulation due mainly to the onset of the 'male jerking phase • was the single most important factor responsible for refractoriness of feaales to further matings. technical stimulation alone caused over 70% refractoriness within 72 hours. this result is comparable to that of normal matings where mechanical stimulation is accompanied by the introduction of aale accessory gland secretion and spermatozoa. in .morsitans, multiple matings were observed to occur early in life; however, once a female became refractory , it remained so for the rest of its life.single matings were found to provide sufficient permatozoa for fertilisation. fatless as old as 60 days retained t heir virility pallidipes was reared on a small scale under controlled conditions of temperature (2~!1°c) and humidity (75 - 80%). female sexual receptivity in !l.. pallidipes was highest when 9 - 13 days old but declined thereafter. maximum mean spermathecal values (msv) were recorded during the period of highest receptivity. the duration of copulation was comparatively short (mean of 24 minutes) for all age groups. though spontaneous ovulation occur red in virgi ns, aating was generally the initiating factor. eighty percent of females at the age of highest receptivity (9 - 13 days old) were inseminated when group-mated compared to 50% for single matings. between 55 - 80% of females were inseminated when they were kept with males for 72 hou r s compared to 12 - 50% insemination when kept for 2q hours. the results also indicate that insemination ra t es are higher (60 - 100%) for females kept in smaller than in larger (60 - 80%) cages. there was no significant difference in the insemination of females kept together with males in continuous darkness (insemination of 50 - 88%) compared to those exposed to alternate 12 hour light and 12 hour dark regimes (insemination of 65- 85%) . "ales of ~pallidipes were most aggressive and made the greatest number r of mating strikes when they were 11 days old. this age of male 'sexual appetitiveness' coincided with the maturation of their accessory reproductive glands, i.e. when the glands had reached 0.17 - 0.20mm• in diameter. "ales were, however, able to inseminate successfully from the age of 7 days onwards. the demonstration that aorsitans and pallidipes do not remote after sever al gonotrophic cycles would enhance the success of the use of the sterile insect technique in their control.the results also show that carefully controlled rearing and environmental conditions, adequate feeding, use of small cages, confinement of males and females for up to 72 hours and mating of 9 - 13 day-old females with over 11 day-old males would facilitate the successful rearing of a laboratory colony of !l_ pallidipes.