Eat or be eaten: prevalence and impact of egg cannibalism on two-spot ladybirds, Adalia bipunctata
Roy, H.E.; Rudge, H.; Goldrick, L.; Hawkins, D.. 2007 Eat or be eaten: prevalence and impact of egg cannibalism on two-spot ladybirds, Adalia bipunctata. Entomologia Experimentalis et Applicata, 125. 33-38. 10.1111/j.1570-7458.2007.00592.xFull text not available from this repository.
Ladybirds commonly engage in cannibalistic behaviour. Egg cannibalism by first instars is considered advantageous to the cannibal, because it not only results in direct metabolic gain but also a reduction in potential competitors. In this study, we quantified the effect of cannibalism on the development rate and survival of Adalia bipunctata (L.) (Coleoptera: Coccinellidae) larvae through development to the adult stage. We also assessed the synchrony of egg-hatching in relation to laying order and compared the proportion of eggs cannibalized in egg batches laid as clusters or linearly. Larvae that had consumed a conspecific egg after hatching reached the adult stage 1.65 days earlier than those larvae that had not. Larval and pupal mortality was lower for cannibals compared to non-cannibals; only 46% of non-cannibalistic individuals reached the adult stage whereas 81% of cannibals pupated successfully. Egg cannibalism is undoubtedly advantageous to A. bipunctata larvae both in terms of faster development and increased survival. There is a positive correlation between laying and hatching order for eggs laid linearly or in a cluster. There was no significant difference in the proportion of eggs hatching in clusters or in a line (80 and 77%, respectively). The remaining eggs were either cannibalized or did not hatch. The ecological implications of these results are discussed with particular reference to trophic egg plasticity.
|Programmes:||CEH Programmes pre-2009 publications > Biodiversity > BD01 Conservation and Restoration of Biodiversity|
|Additional Keywords:||hatching order, development time, survival, Coleoptera Coccinellidae, trophic egg plasticity|
|NORA Subject Terms:||Ecology and Environment|
|Date made live:||29 Oct 2007 11:56|
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