University of Tasmania
139899 - Observations of parasitoid behaviour in both no&%238208;choice and choice tests are consistent with proposed ecological host range.pdf (765 kB)

Observations of parasitoid behaviour in both no‐choice and choice tests are consistent with proposed ecological host range

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journal contribution
posted on 2023-05-20, 16:05 authored by Withers, TM, Geoff AllenGeoff Allen, Todoroki, CL, Pugh, AR, Gresham, BA
The solitary larval endoparasitoid Eadya daenerys Ridenbaugh (Hymenoptera: Braconidae) is a proposed biological control agent of Paropsis charybdis Stål (Coleoptera: Chrysomelidae, Chrysomelinae), a pest of eucalypts in New Zealand. Eadya daenerys oviposition behaviour was examined in two assay types during host range testing, with the aim of improving ecological host range prediction. No‐choice sequential and two‐choice behavioural observations were undertaken against nine closely related species of New Zealand non‐target beetle larvae, including a native beetle, introduced weed biocontrol agents, and invasive paropsine beetles. No behavioural measure was significantly different between no‐choice and two‐choice tests. In sequential no‐choice assays the order of first presentation (target–non‐target) had no significant effect on the median number of attacks or the attack rate while on the plant. Beetle species was the most important factor. Parasitoids expressed significantly lower on‐plant attack rates against non‐targets compared to target P. charybdis larvae. The median number of attacks was always higher towards target larvae than towards non‐target larvae, except for the phylogenetically closest related non‐target Trachymela sloanei (Blackburn) (Coleoptera: Chrysomelidae, Chrysomelinae). Most non‐target larvae were disregarded upon contact, which suggests that the infrequent attack behaviour observed by two individual E. daenerys against Allocharis nr. tarsalis larvae in two‐choice tests and the frass of Chrysolina abchasica (Weise) was probably abnormal host selection behaviour. Results indicate that E. daenerys is unlikely to attack non‐target species apart from Eucalyptus‐feeding invasive paropsines (Chrysomelinae). Non‐lethal negative impacts upon less preferred non‐target larvae are possible if E. daenerys does attack them in the field; however, this is likely to be rare.


Scion New Zealand Forest Research Institute Limited


Publication title

Entomologia Experimentalis et Applicata




1: Special Issue IEIC6






Tasmanian Institute of Agriculture (TIA)


Wiley-Blackwell Publishing Ltd

Place of publication


Rights statement

Copyright 2020 The Netherlands Entomological Society. This is the peer reviewed version of the following article, which has been published in final form at This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.

Repository Status

  • Restricted

Socio-economic Objectives

Control of pests, diseases and exotic species in terrestrial environments