Competition for Aphid Prey between Different Lady Beetle Species in a Laboratory Arena

Christy Leppanen,Serena Gross,Andrei Alyokhin

doi:10.1155/2012/890327

Abstract

Direct competition for aphid prey (Hemiptera: Aphididae) was evaluated between and among several lady beetle species (Coleoptera: Coccinellidae). The behavior of three native (Coccinella trifasciata, Coleomegilla maculata,andHippodamia convergens) and four nonnative (Coccinella septempunctata,Harmonia axyridis,Hippodamia variegata,andPropylea quatuordecimpunctata) lady beetles was observed in laboratory arenas. The beetles were kept alone, paired with conspecifics or paired with heterospecifics, and presented with potato aphids (Macrosiphum euphorbiae).Harmonia axyridiswas the most successful aphid predator in our study, being able to find aphids more quickly and consume more of them compared to most other lady beetle species. It was also by far the most aggressive of the tested species.Coccinella septempunctata, C. trifasciata,andC. maculatagenerally followedH. axyridisin aphid consumption. Prey discovery, consumption, and aggressive behaviors were dependent on which species were present in the arena. Except for the generally superiorH. axyridis, there was no obvious dominance hierarchy among the other tested species and no dichotomy between the native and non-native species. Asymmetric interactions between lady beetle species may affect their abilities to coexist in the same habitat.

Highlights

Lady beetles comprise an ecologically and economically important group of insects that are charismatic and well known to the general public [1, 2]
The behavior of three native (Coccinella trifasciata, Coleomegilla maculata, and Hippodamia convergens) and four nonnative (Coccinella septempunctata, Harmonia axyridis, Hippodamia variegata, and Propylea quatuordecimpunctata) lady beetles was observed in laboratory arenas
We investigated behavior of seven lady beetle species competing for prey in a laboratory arena

Summary

Introduction

Lady beetles comprise an ecologically and economically important group of insects that are charismatic and well known to the general public [1, 2]. Understanding intraguild interactions among lady beetle species is important both for their conservation and for their maximum utilization as biological control agents. Competition is often assumed when predatory species consuming the same prey species are found in the same area [11]. Persistent species that share prey and an evolutionary history are often considered to have achieved a compromise over time, allowing them to coexist by differentially exploiting the same prey species [12, 13]; for example, by foraging at different times [14]. When species consuming the same prey are newly brought together, the ability of each to acquire the same necessary resources may allow for their coexistence [15, 16]. Consumption by a more efficient predator may eventually result in the competitive exclusion of the less efficient predator [16, 20]

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Conclusion