Influence of intraspecific competition for food on the bodyweight of the adult aphidophagous ladybird, Coccinella transversalis

Authors

  • Ahmad Pervez Biocontrol Laboratory, Department of Zoology, Radhey Hari Govt. P.G. College, Kashipur
  • Rupali Sharma Biocontrol Laboratory, Department of Zoology, Radhey Hari Govt. P.G. College, Kashipur, Udham Singh Nagar – 244713, Uttarakhand, India

DOI:

https://doi.org/10.14712/23361964.2021.1

Keywords:

Coccinella transversalis, numerical response, ladybirds, conspecific predator, Intraspecific competition

Abstract

Aggregation of conspecific predators sharing a common prey, influences their bodyweights. We investigated the influence of intraspecific competition of adult ladybirds of Coccinella transversalis Fabricius on their bodyweight feeding on rusty plum aphid, Hysteroneura setariae (Thomas). Adult males and females consumed a significantly greater number of aphids with increase in predator-density, however, the aphid-consumption per predator declined with this increase. The weight gain per predator also decreased linearly with increase in the density of both male and female predators. This indicates that the weight-gain of the predator is a function of the prey consumed. The searching efficiency decreased with increase in predator density due to mutual inference. The mutual interference constants for adult male and female ladybirds were −0.419 and −0.546, respectively. The females consumed a greater number of aphids than males. The killing power of the ladybird denoted by the k-value increased curvilinearly with increase in predator density. We conclude that prey consumption is a function of body size and that the offspring of those that aggregate at low densities in prey-rich habitats develop into large adults.

Author Biography

Ahmad Pervez, Biocontrol Laboratory, Department of Zoology, Radhey Hari Govt. P.G. College, Kashipur

Assistant Professor in Department of Zoology

Published

2021-06-20

Issue

Section

Articles