Potential impact of the native hyperparasitoid Conura albifrons (Hymenoptera: Chalcididae) on the exotic biological control agent Diadromus pulchellus (Hymenoptera: Ichneumonidae)

Citation

Miall, J.H., Abram, P.K., Cappuccino, N., Mason, P.G. (2014). Potential impact of the native hyperparasitoid Conura albifrons (Hymenoptera: Chalcididae) on the exotic biological control agent Diadromus pulchellus (Hymenoptera: Ichneumonidae). Biocontrol Science and Technology, [online] 24(6), 611-624. http://dx.doi.org/10.1080/09583157.2014.883361

Plain language summary

This studied examined the potential negative impact of a native generalist parasite on the establishment of a biological control agent introduced to control the invasive alien leek moth. The results suggest that the native generalist parasite will attack both the leek moth and the introduced biological control agent. This could have a negative impact on the ability of the biological control to increase in numbers and delay reduction in leek moth populations.

Abstract

The solitary pupal parasitoid Diadromus pulchellus was released in 2010 as a classical biological control agent against leek moth, Acrolepiopsis assectella, an important new pest of onion crops, Allium spp. in Eastern North America. Post-release monitoring using sentinel leek moth pupae revealed that the facultative hyperparasitoid Conura albifrons was attacking leek moth and potentially D. pulchellus as well. We used laboratory choice and no-choice tests to assess the potential impact of C. albifrons on leek moth and D. pulchellus. C. albifrons is capable of developing in newly formed leek moth pupae and leek moth pupae containing first instar D. pulchellus, as well as in fully developed D. pulchellus pupae. Survivorship of both leek moth and D. pulchellus exposed to C. albifrons was significantly lower than that of unexposed controls. In choice trials, prior host experience significantly influenced host choice by C. albifrons. These results suggest that C. albifrons could impact the establishment of D. pulchellus through both competition and intraguild predation, and that the impact has the potential to change as the relative frequency of the two hosts shifts in field populations. © 2014 © 2014 The contribution of Jacob H. Miall and Peter G. Mason is authored as part of their employment by Agriculture and Agri-Food Canada (AAFC), and copyright is asserted in the contribution by Her Majesty the Queen in Right of Canada. Paul K. Abram and Naomi Cappuccino hereby waive their right to any copyright in the Article but not their right to be named as co-authors of the Article.