Retrospective risk assessment reveals likelihood of potential non-target attack and parasitism by Cotesia urabae (Hymenoptera: Braconidae): a comparison between laboratory and field-cage testing results

Publication date: Available online 24 August 2016 Source:Biological Control Author(s): G.A. Avila, T.M. Withers, G.I. Holwell We conducted retrospective non-target risk assessment with the larval endoparasitoid Cotesia urabae (Hymenoptera: Braconidae), via sequential no-choice tests, to assess the potential risk posed to two New Zealand endemic species: the magpie moth, Nyctemera annulata (Lepidoptera: Erebidae), and the common forest looper Pseudocoremia suavis (Lepidoptera: Geometridae), as well as to the beneficial biological control agent, the cinnabar moth Tyria jacobaeae (Lepidoptera: Erebidae). Under no-choice laboratory conditions C. urabae did oviposit in T. jacobaeae and N. annulata, and parasitism was confirmed upon dissection of both species at a rate similar to the target host, Uraba lugens (Lepidoptera: Nolidae). Mean attack frequency differed significantly between the three non-targets tested and the target host, where only N. annulata and T. jacobaeae were found to be attacked at a similar rate to the target host U. lugens. However, time to attack was significantly faster against the target host than the non-targets. When oviposition-experienced and naïve C. urabae females were compared, both showed similar mean attack frequencies but experienced parasitoids showed a shorter mean time to attack than naïve parasitoids. Parasitism of N. annulata under semi-natural field conditions was also investigated in field cages. Dissections of N. annulata larvae fro...
Source: Biological Control - Category: Biology Source Type: research