The seasonal abundance of the newly established parasitoid complex of the Eucalyptus tortoise beetle (<i>Paropsis charybdis</i>)

Abstract

Enoggera nassaui has been the key biological control agent of the eucalyptus tortoise beetle Paropsis charybdis since 1987. In 2001 a second egg parasitoid Neopolycystus insectifurax as well as an obligate hyperparasitoid of E. nassaui, Baeoanusia albifunicle were detected in New Zealand. Monitoring of Eucalyptus nitens plantations in the central North Island revealed that 50% of P. charybdis eggs in half the sites were parasitised by E. nassaui in early summer. However, later in the season this was followed by a reduction to 10% parasitism by E. nassaui, the remaining 40% of parasitised eggs being hyperparasitised by B. albifunicle. Neopolycystus insectifurax parasitised an additional 35-100% of eggs in late summer. This indicates that, while B. albifunicle has the potential to severely reduce the effectiveness of E. nassaui, the new agent N. insectifurax is a promising alternative.

Detection of a Tasmanian strain of the biological control agent <i>Enoggera nassaui</i> Girault (Hymenoptera Pteromalidae) using mitochondrial COI

“…Firstly, recovery of E. nassaui was reduced by Baeoanusia albifunicle Girault (Hymenoptera: Encyrtidae), an obligate hyperparasitoid of E. nassaui (Tribe 2000). High hyperparasitism rates and competition from another self introduced egg parasitoid were recorded by Jones & Withers (2003). Because of this situation, there appears to be little future value in monitoring the effect of Tasmanian E. nassaui on P. charybdis since the parasitoid has been rendered relatively ineffective.…”

Incidence of and defoliation by a newly introduced pest, <i>Paropsisterna variicollis</i> (Coleoptera: Chrysomelidae), on eleven durable <i>Eucalyptus</i> species in Hawke’s Bay, New Zealand

“…This indicates the sampling period of 18 to 26 January used here may not have been well timed to capture these important early developmental stages. Both Murphy and Kay (2000) and Jones & Withers (2003) noted January as being between the first (spring) and second (summer) generations of P. charybdis and this may have also been the case for Pst. variicollis.…”

Selecting potential nontarget species for host range testing of <i>Eadya paropsidis</i>

“…The target pest P. charybdis is broadly bivoltine in NZ. Larvae are present from November to December, and February to March (Bain & Kay 1989;Murphy & Kay 2000;Jones & Withers 2003), with overlapping adult generations. Rice (2005b) documented adult E. paropsidis activity in the field from adult emergence traps, malaise traps and parasitised larvae collections and found adults to be active from early December to early February but peaking in December.…”