Abstract:

Objective: In recent year, a leaf gall inducer has been found on Eucalyptus trees in China. It produces small herpetiform galls on leaves and causes a large number leaves fell. In this study, we classified and identified the invasive pest, and determined the type of pest in order to provide reference for the prevention and control of this invasive pest. Method: Totally 120 leaves from Eucalyptus variety Leiling No. 1 with galls were collected in Hepu County, Beihai City, Guangxi, in January and February 2023, and incubated in two transparent plastic baskets. The small wasps that emerged from galls were collected and counted daily, as well as identified. Result: Totally 198 small wasps that form galls were raised. After taxonomic study, the pest was identified as Ophelimus maskelli (Ashmead) (Hymenoptera: Chalcidoidea: Eulophidae). This was the first discovery of the pest in China. The species is native to Eucalyptus trees in New Zealand and Australia. A detailed description of the pest was given in the present paper with color photos, as well as a diagnosis method was provided for distinguishing the species from other species in this genus. Conclusion: The pest O. maskelli found in Guangxi could induce galls on leaves of many Eucalyptus species, causing a large number of leaves shedding and affecting the growth of Eucalyptus trees, and now has become a severe invasive pest in China. The more attention should be paid for controlling the new pest. Fortunately the pest parasitoid Closterocerus chamaeleon (Girault) (Hymenoptera: Eulophidae) was also found during the present investigation. The parasitoid has high parasitism and could be used for biological control of the pest.

Key words: Eucalyptus trees, gall inducer, Ophelimus maskelli (Ashmead), discovering in China