Laboratory and field investigations into sex attraction and mating behaviour ofGlossina morsitans orientalisVanderplank have been described. Male flies were not attracted to volatile and soluble compounds from two- to three-day-old mature virgin females, or to virgin females in a simple olfactometer. Removal of antennae from either sex did not appreciably reduce insemination rates after 24–48-h mating periods compared with normal flies. Similar numbers of wild male flies were caught off oxen baited or non-baited with mature virgin females.G. m. orientalisprobably does not produce a pheromone.Male flies appeared to be sexually activated only after movement by the female. Mating success was reduced in the dark and when the male's eyes were painted, but blinding the female fly did not reduce insemination. Mating was similar with or without wings and halteres and the sounds produced by them.Time between pairing the sexes and the start of mating tended to increase, and the percentage of inseminated females accepting two or more matings decreased, after the first copulation. Female flies rarely re-mated within a day. Virgin female flies accepted males passively with partly open wings, and mated females rejected further copulation with closed wings, activity to shake the male off, and primarily a downward-curved abdomen. Virgin female flies mated for periods of 1–45 min did not receive sperm but successfulad libitummating was reduced a day later. Insemination rates decreased with females older than seven days and reached zero 28–83 days after eclosion, while 37-day-old males inseminated 93% of young females.
Sufficient pupae of G. pallidipes Aust. for testing were available from the Zambezi valley only between September and early November and were of all ages. These pupae or the adult fly were exposed to gamma-radiation from a 60Co source at rates between 54 and 122 rads per min., and reproduction and mortality were studied by described procedures.Effective pupal mortality due to radiation increased, and the proportion of males among the viable emerging flies decreased, with dosage between 4,000 and 16,000 rads. Eeproduction and survival of adult males emerging from treated pupae decreased with an increase in dosage and a decrease in pupal age at the time of treatment. Irradiation of adult males within three days of emergence produced slightly lower levels of sterility and similar survivals. Complete male sterility was rarely obtained with any of the treatments, though all the females, with one exception, were sterilised from 4,000 rads upwards, but the flies were fully competitive with untreated males and reduced reproduction below expected values. Treated males were fully capable of inseminating female flies and the sperm was motile and apparently behaved normally. Dominant lethality in the males appeared to be expressed by the failure to produce pupae and in the females by the complete failure of oogenesis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.