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

Abstract

In March 2016, an incursion of the paropsine beetle Paropsisterna variicollis (eucalyptus variegated beetle) was detected in the Hawke's Bay during routine Forest Biosecurity Surveillance. Paropsines cause significant damage to eucalypt plantations in several parts of the world. A survey of three Hawke's Bay sites containing 11 durable eucalypt species was conducted in January 2017. Defoliation by paropsines, and numbers of eggs, larvae and adults were recorded. Adult Pst. variicollis were observed on all eucalypt species, and were present in larger numbers than Paropsis charybdis in two sites. Eucalyptus bosistoana sustained the greatest defoliation and incidence of eggs and larvae, and E. macrorhyncha the least. Parasitism of Pst. variicollis eggs was observed but the agent was not definitively confirmed. Results indicate Pst. variicollis will exhibit a wide host range in New Zealand but variability observed in the levels of defoliation between species may be linked to heritable traits that can be exploited through current breeding programmes.