Effect of the presence of predatory cues and hunger on cannibalistic behaviour of ladybird beetle, Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae)

• Published in: Ecological entomology Vol. 48; no. 1; pp. 1 - 10
• Main Authors: Yadav, Tripti, Omkar, Mishra, Geetanjali
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.02.2023; Wiley Subscription Services, Inc
• Subjects: Adults; Cannibalism; cannibalistic; conspecifics; Eggs; Fecundity; Females; Hunger; Latency; Menochilus sexmaculatus; non‐cannibalistic; Population dynamics; predation cues; Risk assessment; Starvation
• ISSN: 0307-6946; 1365-2311
• DOI: 10.1111/een.13196

Cannibalism and its role in population dynamics, along with various factors influencing the rate of cannibalism, have been widely studied across taxa. The effects of predatory cue concentrations and starvation on cannibalistic tendencies and other life‐history traits in cannibalistic and non‐cannibalistic adults of Menochilus sexmaculatus were investigated. Egg cannibalism increased with increasing predatory cue concentration and was maximum in high predatory cue treatment; increased with starvation irrespective of their diet history. Latency to cannibalise eggs was shorter for cannibalistic adults as compared to non‐cannibalistic adults irrespective of their hunger status and concentration of conspecific cues. Non‐cannibalistic females have higher fecundity than cannibalistic females. In conclusion, both cannibalistic and non‐cannibalistic individuals respond differently to intrinsic (hunger) and extrinsic cues (predatory cue concentrations). Cannibalistic individuals cannibalise more than non‐cannibalistic ones at low levels of starvation and predatory cues. Our finding suggests that cannibalistic individuals are better at assessing the risk and removing future competitors, which might favour these individuals over non‐cannibalistic ones in adverse conditions and increased competition. Cannibalistic and non‐cannibalistic individuals responded differently to intrinsic (hunger) and extrinsic cues (predatory cues). At low levels of starvation and predatory cues, cannibalistic individuals cannibalised more than non‐cannibalistic individuals. During extremely adverse conditions and increased competition, cannibalistic individuals might be favoured over non‐cannibalistic ones, since they can assess the risks and remove potential competitors. Predatory cues and hunger modulate cannibalistic behaviour