Comparison of the demographic parameters and survival of two phenotypes of Harmonia axyridis (Coleoptera: Coccinellidae)

Eleni Zeki,Dimitrios C Kontodimas,Nikos Demiris,Nikos E Papanikolaou

doi:10.14411/eje.2015.004

Abstract

This paper reports the results of a comparative study of the demographic parameters of two phenotypes of Harmonia axyridis Pallas, reared on the black bean aphid, Aphis fabae Scopoli at 25 ± 1°C, 65 ± 2% RH and a photoperiod of 16L : 8D. The values of the intrinsic rate of increase and the finite rate of increase, which were obtained by bootstrapping, were greater for the succinea morph (0.182 females/female/d and 1.200, respectively) than the spectabilis morph (0.168 females/female/d and 1.183, respectively). The net reproductive rates and mean generation times of the two morphs did not differ. The risk of death of the succinea morph was significantly greater. However, there was no significant difference between the estimated survival times. Mean survival times were 95.2 d and 89.3 d for the spectabilis and succinea morphs, respectively.

Highlights

Predaceous coccinellids are common biological control agents of insect pests, preying principally on hemipterous insects, such as aphids and coccids (Dixon, 2000; Hodek et al, 2012)
Ware & Majerus (2008) alleged that H. axyridis is an intraguild predator of several ladybird species and there are a number of studies that indicate H. axyridis is a strong asymmetrical intraguild predator of other guild members (Pell et al, 2008, Nedved et al, 2013)
Our study provides evidence that phenotype is associated with differences in the performance of H. axyridis

Summary

Introduction

Predaceous coccinellids are common biological control agents of insect pests, preying principally on hemipterous insects, such as aphids and coccids (Dixon, 2000; Hodek et al, 2012). Harmonia axyridis (Pallas) is a polyphagous predator, preying on aphids, coccids, psyllids and other insect prey (Hodek et al, 2012). Augmentative releases of H. axyridis have been used to control aphid populations in several regions in Europe and U.S.A, because this species is a voracious predator of aphids (Roy & Wajnberg, 2008). Ware & Majerus (2008) alleged that H. axyridis is an intraguild predator of several ladybird species and there are a number of studies that indicate H. axyridis is a strong asymmetrical intraguild predator of other guild members (Pell et al, 2008, Nedved et al, 2013). The relatively large size and aggressive behaviour of H. axyridis contributes to its success as an intraguild predator, while the defensive chemistry of adults makes them unpalatable to other coccinellids (Hough-Goldstein et al, 1996) and the adults are protected against bird predators due to their colouration (Pruchova et al, 2014)

Methods

Results

Conclusion