Australian Journal of Entomology (2006) 45, 215–218 © 2006 The Authors Journal compilation © 2006 Australian Entomological Society doi:10.1111/j.1440-6055.2006.00532.x Blackwell Publishing AsiaMelbourne, AustraliaAENAustralian Journal of Entomology1326-6756(c) 2006 The Authors; Journal compilation (c) 2006 Australian Entomological Society? 2006453215218Original ArticleHyperparasitoids of Uraba lugens J A Berry and S Mansfield *berryj@landcareresearch.co.nz Hyperparasitoids of the gum leaf skeletoniser, Uraba lugens Walker (Lepidoptera: Nolidae), with implications for the selection of a biological control agent for Uraba lugens in New Zealand Jocelyn A Berry 1 * and Sarah Mansfield 2 1 Landcare Research, PB 92170, Auckland, New Zealand. 2 Ensis – Forest Biosecurity and Protection, PB 3020, Rotorua, New Zealand. Abstract The hyperparasitoids reared from three species of primary parasitoids of the gum leaf skeletoniser, Uraba lugens Walker (Lepidoptera: Nolidae) collected in South Australia and Tasmania are recorded and discussed. Seven hyperparasitoids were reared. Diatora sp. and ?Paraphylax sp. (Ichneumonidae: Cryptinae); Tetrastichus sp. (Chalcidoidea: Eulophidae); Megadicylus dubius (Girault) (Chalcidoidea: Pteromalidae) and Elasmus sp. (Chalcidoidea: Eulophidae) were reared from Cotesia urabae Austin and Allen (Braconidae: Microgastrinae). Megadicylus dubius, Elasmus sp. and Anastatus sp. (Chalc- idoidea: Eupelmidae) were reared from Dolichogenidea eucalypti Austin and Allen (Braconidae: Microgastrinae). Pediobius bruchicida (Rondani) (Chalcidoidea: Eulophidae) was reared from Euplec- trus sp. (Chalcidoidea: Eulophidae). This appears to be the first record of the cryptine ichneumonid genus Diatora Förster from Australia. Of the seven hyperparasitoid species reared, only one (P. bruchicida) is known to be present in New Zealand. Implications for the selection of a biological control agent for U. lugens in New Zealand are discussed. Some prior misidentifications of associated hyperparasitoids are noted. Key words Australia, Diatora, Eucalyptus, forest, new record. INTRODUCTION Natural enemies that attack biological control agents can seri- ously interfere with the effectiveness of the control provided by the agents. For hyperparasitoids, an inverse relationship between the rate of hyperparasitism and the level of herbivore control by primary parasitoids is often assumed, and there appears to be evidence for this in the short term at least (Rosenheim 1998). A recent example from New Zealand is that of the egg parasitoid Enoggera nassaui (Girault) (Pteromalidae), which was introduced in 1987. It was initially successful in control- ling its target, Paropsis charybdis Stål, the Eucalyptus tortoise beetle (Chrysomelidae). In 2001 an encyrtid hyperparasitoid (Baeoanusia albifunicle Girault) was first recorded attacking E. nassaui. The hyperparasitoid has suppressed E. nassaui populations so much that at times eucalypt growers have resorted to broad-spectrum insecticides for control of P. charybdis (Jones & Withers 2003). Clearly, it is not possible to control for exotic hyperparasi- toids which may be accidentally introduced after a control agent has established, as seems to be the case with B. albifunicle. However, where there is a choice of biological control agents, the presence of known natural enemies in the target country is one factor that should be taken into consideration when weighing up risks and benefits of an introduction. Syrett et al. (1999) cited the presence of the parasitoid Pteromalus sequester Walker (Pteromalidae) in New Zealand as one factor against introducing the apionid Exapion fuscir- ostra (F.) for biological control of broom. Sometimes the presence of natural enemies may be considered to be an acceptable risk. The parasitoid Megastigmus sp. (Torymidae) was known to be present in New Zealand when approval for the release of one of its hosts, the mist flower gall fly (Proce- cidochares alani Steyskal) was sought and gained. In Australia this species of Megastigmus was known to have attacked both P. alani and P. utilis Stone, a control agent introduced against Mexican devil weed (EE Grissell, USDA, pers. comm. 2000). The parasitoid is said to have been responsible for greatly reducing populations of P. utilis within 2 years of its introduc- tion in Queensland (Dodd 1961). Possible direct and indirect effects mediated by Megastigmus in New Zealand were con- sidered in the Environmental Risk Management Authority decision (ERMA Decision NOR99004 2000). The introduc- tion took place in February 2001 and P. alani has now estab- lished successfully in New Zealand. As expected, parasitism by Megastigmus has been recorded, but the rate appears to be fairly low (less than 4% of galls on mist flower had parasitoids reared from them in a survey of four sites in Northland) (Q Paynter pers. comm. 2005).