Host specificity testing predicts Eadya daenerys (Hym.: Braconidae), a potential biological control agent for the invasive pest Paropsis charybdis will be host specific to Paropsini (Col.: Chrysomelidae: Chrysomelinae)

The introduction of a new biological control agent is being proposed in New Zealand for Paropsis charybdis (Coleoptera: Chrysomelidae: Chrysomelinae), a eucalypt pest of Australian origin. The Australian solitary larval endoparasitoid Eadya daenerys (Hymenoptera: Braconidae) has been the subject of host range testing against non-target species in containment. The results of testing against two pest paropsine beetles, one native species, and six beneficial biological control agents are reported. All non-target species were springtime-active, external leaf-feeding larvae. Physiological development through to emergence of the parasitoid larva from the host only occurred within species in the tribe Chrysomelini; that is, the target P. charybdis (30 34%) and another eucalypt pest Trachymela sloanei (12.5%). Unsuccessful internal parasitism by E. daenerys was discovered upon dissection of four other non-target Chrysomelinae, Dicranosterna semipunctata (1.6%), Allocharis nr tarsalis (7.5%), Chrysolina abchasica (1.8%) and Gonioctena olivaceae (5.2%). Although not a physiological host for the parasitoid, the attack on the endemic beetle larva A. nr tarsalis was concerning. Oviposition attackinsertions were occasionally observed in all non-target species in the petri-dish assays (mean 0 1.6 attacks/min) including A. nr tarsalis, however they were significantly less when compared to P. charybdis and T. sloanei (mean 1.1 – 4.4 attacks/min). The order of presentation had no significant impact on the propensity of E. daenerys to attack nontargets. Considering the low propensity to attack, the different feeding niche (shrubs unrelated to Eucalyptus) and the sub-alpine habitat (greater than 1200m a.s.l.) of New Zealand endemic beetles such as A. nr tarsalis, we conclude the likelihood that this parasitoid will encounter and cause mortality to A. nr tarsalis is very low. Our results are consistent with field host relationship studies in Tasmania, and in combination indicate that E. daenerys is highly unlikely to attack any species apart from pest paropsine (Chrysomelini) species feeding on Eucalyptus. Eadya daenerys is proposed as a safe parasitoid for release into the New Zealand environment.