ABSTRACT
One and seven days old larvae of the flesh fly, Parasarcophaga argyrostoma were exposed to doses ranging from 1-90 Gy. Lower doses ranging from 1-9 Gy applied to young larvae accelerate larval development whereas old larvae responded to doses from 10-90 Gy by a remarkable retardation of the larval and pupal development. Reduction in percentage pupation and adult emergence were noticed with increment in the radiation doses applied. This reduction was higher for irradiated seven days old larvae than the one day old larvae at all doses applied, indicating that young larvae were more susceptible to gamma radiation than the older one. At higher doses (30-70 Gy) the pupae could not continue their development and died within 17 days after pupation. The longevity of adults resulted from irradiated larvae was decreased by increasing the radiation dosage and it was found that adults emerging from irradiated young larvae lived shorter than those from irradiated young ones, the fecundity of adults resulted from irradiated larvae was also decreased by gamma irradiation exposures. The percentage reduction of larviposition was 100% for irradiated females with 8 Gy while that of irradiated males was 97.5% indicating that females were more sensitive to radiation than males.
Subject(s)
Diptera/radiation effects , Animals , Diptera/growth & development , Female , Gamma Rays , Larva/radiation effects , MaleABSTRACT
Borrelia crocidurae infection rates in different organs of adult Ornithodoros (Pavlovskyella) erraticus and O. (Ornithodoros) savignyi were studied at intervals during a 60-day period following an infective meal. The spirochaetes persisted in tick guts for 1 month, were first observed in other organs 1-7 days post-feeding, and persisted for 20-60 days in different organs. The ovaries, Gene's organ, testes and male accessory glands of only O. erraticus were infected. The infection rates in adult and immature O. erraticus and O. savignyi post-feeding on infected hamsters were 26.7-60 X 0% and 26.7-80.0%, respectively. Spirochaete trans-stadial transfer from originally infected larval O. erraticus to first-instar nymphs (N1) was 33.3%; to subsequent N2-N5 it was 40.0-60.0%. Infection rates in the resulting adults were 26.7% (males) and 46.7% (females). In O. savignyi, trans-stadial transfer from originally infected N1 to N2 was 26.7% and to subsequent N3-N7 13.3-33.3%; of the resulting males and females, 20.0% were infected. Transovarial transmission from female O. erraticus infected as adults occurred after the second gonotrophic cycle to 33.3-53.3% of the F1 larvae, and to 26.7 and 46.7% of the F1 males and females, respectively. All infected F1 females transmitted the spirochaetes to 26.7-73.3% of the F2 larval progeny after the first gonotrophic cycle. Transovarial transmission was not observed in O. savignyi.
