bstract-Heliothis armigera (Hubner) completed five generations in the laboratory, as well as in the field, in a year. The first generation was completed from the first week of December to the fourth week of February, the second generation from the second week of February to first week of April. The third generation from third week of August passing through the extreme summer, the fourth generation during monsoon period and the fifth last generation from the third week of September to the fourth week of November. The seasonal variation in generation time is largely due to extreme variations in ecological factors, temperature (10-45°C), photoperiod (10-14 hr), relative humidity (15-95%) and rainfall. These factors also affect the percentage of pupation, emergence and fecundity of the female moths. Males outnumbered the females in the first, second and fifth generation. The females lived longer than males in all generations.Resume-Heliothis armigera (Hubner) comporte 5 generations par an aussi bien en laboratoire que dans les conditions naturelles. La premiere generation est achevee entre la premiere semaine de decembre et la quatrieme semaine de fevrier, la deuxieme entre la seconde semaine de fevrier et la premiere semaine d'avril. La troisieme generation a partir de la troisieme semaine d'aout et a travers les conditions rudes de Pete; la quatrieme generation pendant la periode de la mousson et la cinquieme et derniere generation, entre la troisieme semaine de septembre et la quatrieme semaine de novembre. La fluctuation saisonniere quant a la duree d'une generation est essentieliement liee a la variation extreme dans les facteurs ecologiques: temperature (10-45°C), la photope'riode (10-14 h), I'humidite relative (15-95%) et la pluviometrie. Ces facteurs affectent egalement le pourcentage de pupaison et d'emergence, et la fecondite des femelles. Les males surpassent en nombre les femelles dans la premiere, deuxieme, et cinquieme generation. Les femelles vivent plus longtemps que les males quelque soit la generation considered.

Heliothis armigera was reared on four varieties of gram, namely Radhe, Desi, K168 and K4. Growth was studied under laboratory conditions from January to March 1986. The weight acquired by the mature larvae showed variation among the tested food plants. Weight of the pupa also varied in response to rearing on different varieties of gram. Radhe induced the quickest pupation. The emergence of the insect varied from 61–92% among the tested varieties of gram. Fecundity also differed markedly from variety to variety.

Effects of different levels of larval density (1, 5, 10, 15, 20, 25 larvae/container) on development, growth and reproduction of Earias vittella were examined under laboratory conditions when the temperature ranged from 22–33°C and R. H. varied from 57–91%‐Larval survival was found to be negatively correlated to the level of density. However, it reduced the larval and pupal weights. Crowding also decreased the fecundity of adults. Hatching of the eggs laid by the females was not affected by the larval crowding.

No abstract

Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), commonly called gram pod borer, is a serious pest of pulse crops in India and damages chickpea (Cicer arietinum L). On average a 30% crop loss is reported. One of the potential natural enemies reported for its biological control is Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae), an idiobiont parasitic wasp that attacks second instar larvae of the pod borer. Male-biased sex ratios hinder efforts to mass release parasitic Hymenoptera for biological control by making the production of females costly. Parental age at time of mating is known to affect the progeny sex ratio in some Braconidae. In this view, we examined the reproduction and survival of the parasitoid C. chlorideae in the laboratory [22 ± 4°C, 70 ± 10% R.H. and 10:14 h light:dark photoperiod]. All the nine (i.e. 3 9 3) combinations of possible mating were made for males and females, being each of different age groups (0-12, 48-60 and 96-108 h old). Second instar larvae of the pod borer were reared on chickpea and exposed to mated females of different mating age group combinations. Results revealed that (a) newly emerged females (0-12 h old) mated to aged males yielded more progeny contrasted to the older females inseminated by newly emerged males (0-12 h old). This implies that increased maternal age at mating caused greater reduction in the progeny yield than that of paternal age; (b) the progeny sex ratio was lowest (0.344 ± 0.057) (mean ± SD) when parents mated just after emergence (0-12 h old). It became more and more male biased as parents were deprived of mate and was highest (0.666 ± 0.701) for 96-108 h old parents. The analysis of variance of the data shows that mate deprived males caused greater contribution in the production of sons, resulting a male-biased progeny sex ratio. Our conclusion indicate that newly emerged parasitoids (0-12 h old) are most fecund and should be used in rearing practices in order to enhance the progeny yield, particularly with respect to daughters.