Effect of gamma-radiation on Glossina pallidipes Aust.

Abstract

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.

Survival and reproductive potential of gamma irradiated male Glossina pallidipes Austen

“…commun.). In general, these observations are also in agreement with conclusions made by Dean & Clements (1969), where they observed similar mating behaviour with both treated and untreated flies.…”

“…Integration of the sterile insect technique (SIT), at the final phase of a control programme, would result in eradication as has recently been clearly demonstrated in Zanzibar (Vreysen et al, 2000) In preparation for an SIT component of the G. pallidipes eradication project in the Southern Rift valley, Ethiopia, the effect of gamma irradiation on laboratory reared sexually mature male G. pallidipes was studied. The effect of gamma irradiation on a number of economically important tsetse species has been investigated (see Vreysen et al, 1996) but not on G. pallidipes except for early work on radiation on field collected pupae (Dean & Clements, 1969). In the present paper, the survival of irradiated males and fecundity of females mated to irradiated males was monitored and a sterilising dose identified.…”

The Viability, Fertility and Behaviour of Tsetse Flies (Glossina Morsitans) Sterilized by Irradiation Under Various Conditions

“…Several authors have provided information on male survival and fertility following gamma-radiation in air given to different life-stages of Glossina spp. (Potts, 1958;Itard, 1968Itard, , 1970Curtis, 1968;Dean & Clements, 1969;Dean & Wortham, 1969;Dean, Dame & Birkenmeyer, 1969). As with other insects, fewer survive following irradiation of earlier stages in the life-cycle (Dean & Wortham, 1969) : hence, treatment of adults or of late pupae is indicated.…”

USE OF NITROGEN AND CHILLING IN THE PRODUCTION OF RADIATION‐INDUCED STERILITY IN THE TSETSE FLY GLOSSINA MORSITANS

“…Gamma-radiation appears to be safer, more convenient and reliable than chemosterilants in current use. Radiation sterilization of males has been studied in several Glossina species (Potts, 1958;Itard, 1968Itard, , 1970Curtis, 1968;Dean & Clements, 1969;Dean & Wortham, 1969). Tsetse flies require higher doses for 950/0 sterility than any other Diptera studied (data assembled by LaChance, Schmidt & Bushland, 1967;Curtis, 1971).…”