P. J. Edward George ¹, R. Seenivasagan ², G. Karuppasamy ²

Affiliations
1 Entomology Research Unit, St.Xavier's College, Palayankottai 627 002, Tamil Nadu, IN
2 Entomology Research Institute, Loyola College, Chennai 600 034, Tamil Nadu, IN

Abstract

The life table studies on Sycancus collaris Fabricius (Heteroptera: Reduviidae) under laboratory conditions revealed that the net reproductive rate (R₀) of the species was 30.46 female eggs/female. The true intrinsic rate of natural increase (r_m) was 0.066. The population multiplied 1.59 times every week and the time taken for the doubling of predator was 10.56 days. The total nymphal duration was 49.3±1.95 days. The life span of females was more (45.17±1.83 days) than males (31.83±2.48 days).

Keywords

Development, Intrinsic Rate of Increase, Life Table, Netreproductive Rate, Spodoptera litura, Sycanus collaris.

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P. J. Edward George ¹, R. Seenivasagan ², S. Kannan ²

Affiliations
1 Entomology Research Unit, St.Xavier's College, Palayankottai 627 002,Tamil Nadu, IN
2 Entomology Research Institute, Loyola College, Chennai 600034, Tamil Nadu, IN

Abstract

The life table and intrinsic rate of increase of Acanthaspis pedestris Stal (Heteroptera: Reduviidae) a predator of lepidopteran insect pests viz., Spodoptera litura (Fabricius), Earias vittella (Fabricius) and Corcyra cephalonica (Stainton) are discussed. The intrinsic rates of increase were 0.039, 0.032 and 0.028 per female per day on S. litura, E. vittella and C. cephalonica, respectively. The population multiplied 44.44, 24.79 and 19.36 times in the cohort generation time of 115.19,121.82 and 133.19 days on S. litura, E. vittella and C. cephalonica, respectively.

Keywords

Acanthaspis pedestris, Corcyra cephalonica, Earias vittella, Intrinsic Rate of Increase, Life Table, Spodoptera litura.

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P. J. Edward George ¹, R. Seenivasagan ²

Affiliations
1 Entomology Research Unit, St. Xavier's College, Palayamkottai 627 002, Tamil Nadu, IN
2 Entomology Research Institute, Loyola College, Chennai 600034, Tamil Nadu, IN

Abstract

Comparative predatory efficiency of Rhynocoris marginatus (Fabricius) was assessed on two cotton pests namely, Helicoverpa armigera (Hubner) and Spodoptera litura (Fabricius). Gradual increase in prey consumption was recorded by the progression of the developmental stages of the predator. Adult females consumed more than males and consumption decreased with the later prey instars. Among the two prey species, S. litura was more preferred.

Keywords

Helicoverpa armigera, Predatory efficiency, Rhynocoris marginatus, Spodoptera litura.

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