M. Sharmila ¹, P. Bijaya ¹, T. K. Singh ¹, B. K. Agarwala ²

Affiliations
1 Aphid Research Laboratory, Department of Life Sciences, Manipur University, Canchipur 795 003, Manipur, IN
2 Department of Life Sciences, Tripura University, Agartala 799 130, Tripura, IN

Abstract

The predatory efficiency and survival of immature stages of an aphidophagous ladybeetle, Harmonia dimidiata (Fabricius) were investigated at five different prey densities, viz., 25, 50, 75, 100 and 125 using Cervaphis quercus Takahashi as prey. A substantial influence of prey density on the rate of larval growth and development was observed. Increased prey density reduced the developmental period. The study also revealed that larval development could be completed at the lowest prey density of 25 prey aphids. The analysis revealed a positive correlation between survival of developmental stages and density of prey provided. A relative increase in weight was observed with increasing density of aphid prey, but only up to a prey density of 100. The functional response exhibited by fourth instar larva exemplified type II predatory response with optimum response at a prey density of 100.

Keywords

Harmonia dimidiata, Cervaphis quercus, Predatory Efficiency, Prey Density, Immature Survival.

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B. K. Agarwala ¹, P. Bardhan Roy ¹

Affiliations
1 Ecology and Systematics Laboratory, Department of Life Sciences, Tripura University, Agartala 799004, IN

Abstract

Early and late instar caterpillars of Spodoptera litura (Fabricius), a known pest of many vegetable crops and other economically important plants, readily ate live Aphis craccivora Koch and eggs of coccinellids, Cheilomenes sexmaculata (Fabricius) and Coccinella transversalis Fabricius in the laboratory. These caterpillars developed normally, similar to those caterpillars which were exclusively fed on foliage of mustard or bean plants. Such a feeding habit of S. litura reported here for the first time, could have important bearing in relation to prey-predator interaction in a seasonal habitat.

Keywords

Aphids, Carnivory, Cheilomenes sexmaculata, Coccinella transversalis, Spodoptera litura.

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M. Sen Choudhuri ¹, K. Chaudhuri ¹, B. K. Agarwala ¹

Affiliations
1 Department of Life Science, Tripura University, Agartala 799004, IN

Abstract

Aphidophagous ladybird beetle, Cheilomenes sexmaculatus (Fabricius) developed and reproduced in captivity when offered alternative foods like drone honeybee powder, ant eggs or a combination of ant eggs and aphids (2:1). However, female ladybird beetles showed longer pre-reproductive delay and laid less number of viable eggs by feeding on alternative foods in comparison to those females which fed on living aphids. Adults fed on drone honeybee powder oviposited more number of eggs and such adults lived longer than those fed on ant eggs or a combination of ant eggs and aphids.

Keywords

Ladybird Beetles, Cheilomenes sexmaculatus, Alternative Foods.

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B. K. Agarwala ¹, A. K. Bhaumik ¹, S. Das ¹

Affiliations
1 Department of Life Science, Tripura University, Agartala 799 004, IN

Abstract

Monobremia rishikeshensis Grover (Diptera, Cecidomyiidae) a predator of Aphis citricola Goot (Homoptera, Aphididae) infesting Chromolina odorata L., a common shrub weed in north-east India oviposit in aphid colonies and the larvae fed on the body fluids by piercing the prey. Pre-adult development took 17.5 - 19.6 days. In winter months, larvae spun cocoons and entered diapause until the rains in early summer. Observations on the life cycle and an inter-relationship in predator-prey-host plant are presented.

Keywords

Monobremia rishikeshensis, Predator, Aphis citricola, Bionomics.

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