Parasitoids associated to Ophelimus eucalypti (gahan) (Hymenoptera: Eulophidae) on Eucalyptus (Myrtaceae) plantations in North Sumatra, Indonesia

Abstract

Eucalyptus (Myrtaceae) is planted to produce materials such as paper, pulp, viscose, and wood. The eucalyptus gall wasp, Ophelimus eucalypti (Gahan) (Hymenoptera: Eulophidae), induces the formation of galls on the leaves of Eucalyptus in North Sumatra, Indonesia. However, the identity of parasitoids associated with O. eucalypti in the field is poorly known. The study aimed to identify the parasitoids and their most prevalent species associated with O. eucalypti. Leaves of Eucalyptus with parasitized galls were sampled from January to October 2021 at Toba, North Tapanuli, and Samosir districts, North Sumatra. The collected material was incubated in the laboratory until gall wasp adults for its parasitoids emerged. Nine hymenopteran parasitoids of O. eucalypti were recovered and identified via analysis of the external morphology. They are Aprostocetus causalis La Salle & Wu, Aprostocetus Westwood sp., Chrysonotomyia germanica Erdös, Chrysonotomyia Ashmead sp. 1, Chrysonotomyia sp. 2, Closterocerus chamaeleon Westwood (Eulophidae), Eurytoma Illiger sp. (Eurytomidae), Quadrastichus mendeli Kim & La Salle and Tetrastichinae sp. (Eulophidae). The prevalence of Chrysonotomyia spp. parasitoid was the highest in the collection. Therefore, those parasitoids can be considered potential candidates as biological agents in the strategy to control the leaf-gall former O. eucalypti.