Variations in Ophelimus maskelli (Hymenoptera: Eulophidae) population density and infestation on Eucalyptus and the impact of its parasitoid Closterocerus chamaeleon (Hymenoptera: Eulophidae) in Algeria

Abstract Ophelimus maskelli (Ashmead, 1900) (Hymenoptera: Eulophidae) is an invasive species that has spread to Eucalyptus in the recent years in several countries, particularly in the Mediterranean and Africa, causing significant damage to Eucalyptus plantations and nurseries. The present work consists of, firstly, a study focussing on the incidence of infestation and the population dynamics of Ophelimus maskelli on Eucalyptus camalduliensis (Myrtaceae) and secondly, a study evaluating the parasitism of this pest by Closterocerus chamaeleon (Girault, 1922) (Hymenoptera) during two years (2019 and 2020) in two different forests in the region of Oued Smar (Algiers). The study revealed that the incidence of infestations is very high and Closterocerus chamaeleon , the parasitoid of Ophelimus maskelli used in several countries successfully, is present with a considerable rate of parasitism in the two sites; these results are discussed. This invasive species, which has spread in the recent years, requires further investigation in order to develop effective pest management methods that could possibly limit its spread.