First releases and monitoring of the biological control agent Cotesia urabae Austin and Allen (Hymenoptera: Braconidae)

Abstract

In July 2010, the Environmental Risk Management Authority New Zealand (now the Environmental Protection Authority) gave approval for release of the parasitoid Cotesia urabae Austin and Allen (Hymenoptera: Braconidae) as a biological control agent for the gum leaf skeletoniser Uraba lugens Walker Lepidoptera: Nolidae) in New Zealand. Between January and June 2011, five releases of adult C. urabae were made at two different sites in Auckland: three at the Auckland Domain (91 female: 102 male) and two at the Manukau Memorial Gardens (86 female: 54 male). Both release sites were closely monitored throughout 2011. The first cocoons were found one month after the first release, and thus far 132 cocoons have been found at the release sites suggesting initial establishment. The first confirmed progeny of field emerged parents was confirmed at the Auckland Domain in February 2012 with the finding of 18 cocoons at that site. Monitoring is continuing to determine if the population persists and further releases are planned at other sites to ensure establishment. Results of this study along with data gathered from ongoing monitoring will be useful to provide advice and guidelines to replicate a similar biocontrol program in other countries affected by U. lugens in the future.