Effects of gamma-radiation on mature pupae of maize borer, Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae)

Abstract

Mature (5-to 6-day-old) male and female pupae of C. partellus were irradiated at 5 to 20 kilo-Roentgen (kR) and 5 to 10 kR respectively. Emergence of normal appearing moths, pupal periods and adult longevities remained statistically unaffected. Fecundity of normal (nonirradiated) females mated with males irradiated as pupae was nonsignificantly different from control, but fecundity of females irradiated as pupae at 10 kR was significantly reduced when they were mated with normal mates. Dominant lethals of varying intensities were induced at 5-20 kR. However, induction of dominant lethality was sex-as well as dosedependent. Radiation doses inducing 100% dominant lethals in sperm (20 kR) and ova (5 kR) did not mitigate the mating ability of males and receptivity of females. However, receptivity of females was reduced significantly when they were Irradiated as pupae at 10 kR. Rates of embryonation in F, eggs were significantly reduced when normal females were crossed with males irradiated as pupae at 20 kR, but similar effect was observed at 10 kR in reversed crosses. Embryonic development was delayed in eggs obtained from crosses, where male or female parent was irradiated In pupal stage, but in both cases most of the dominant lethals acted late in embryonic development. Resume-Les pupes male et femelles agees (5 a 6 jours) de C. partellus ont ete irradttes a 5-20 kR et 5-10 kR respectivement. L'irradiation n'effecte pas les eclosions, la survie des pupes et la longevity des adultes. La fecondite des femelles normales accouples aux des males irradiees ne differe pas significativement du temoin mais les fecondities des femelles irradiees a 10 kR et accouples avec des males non kradiees ont reduites en fonction de la dose. L'induction de letalite dominante a depended sur les sex et la dose. Les doses de rayonnements necessaires pour 100% letalite dominante en des sperms (20 kR) et des oeufs (5 kR) n'effectuees pas des comportement sexuel chez des mftles et des femelles.Les pupes irradle'es a la dose de 10 kR a provoque l'accouplement des femelles. L'embryon des oeufs F, ete reduites significativement quand la femelles normale ete crolssees avec le male Irradil a la dose de 20 kR a stade de la pupe mais les effets semblable ete observees a la dose de 10 kR quand les femelles irradiees et£ crolsees avec des males normales. Les developpement des embryons sont retardes dans des oeufs obtenir en accouplements des males ou des femelles irradiles a la stade de pupes mais en cheque les deux cases letalite dominante devient plus tard.Mots Clis: Chilo parteUus, rayonnement gamma, pupes, developpement des embryons, 16talit6 dominante

Activity of Chilo partellus (Lepidoptera: Pyralidae): eclosion, mating and oviposition time

“…This is probably due to the fact that females did not have the option to mate on the night of eclosion. Bughio et al (1977) reported that C. partellus was able to mate 17-19 h after eclosion and that maximum (75%) mating was recorded when the moths were 40-44 h old. It is not mentioned if the females had the option to mate on the night of eclosion but peak mating was recorded between 01.00 and 02.00 h and this is several hours before that recorded in the current experiment.…”

“…The differences could arise from different lengths of scotophase. Onset of the 10 h scotophase used in Bughio et al (1977) (12 h scotophase is used in all other studies) is not indicated.…”

“…It has been widely studied, but even so, there are no studies which summarize the major reproductive activities. Apart from a brief report on eclosion (Kanaujia et al, 1981) there are reports that mating occurs in the early hours of the day (Trehan & Butani, 1949), with a peak between 01.00 and 02.00 h (Bughio et al, 1977) or that maximum mating takes place during the first night after emergence, peaking between 05.00 and 07.00 h (Kumar & Saxena, 1985). Unnithan (1988), however, reports that mating starts a few hours after eclosion.…”

Diapause Termination of Chilo partellus (Swinhoe) and Chilo orichalcociliellus Strand (Lepidoptera: Pyralidae)

“…start mating on the night of eclosion (Bughio et al, 1977;Kumar and Saxena, 1985;Pats, 1991). start mating on the night of eclosion (Bughio et al, 1977;Kumar and Saxena, 1985;Pats, 1991).…”