Diversity of hymenopteran egg parasitoids in a citrus orchard ecosystem in northeastern Algeria

Understanding the biodiversity of egg parasitoids in an agroecosystem is crucial for their conservation and integration into an eventual integrated pest management programme, as they act at the embryonic stage of pests. This study focused on the inventory of egg parasitoid Hymenoptera in an orange orchard located in Guelma region, northeastern Algeria, from February 2016 to May 2017, using yellow sticky traps. The semi-arid climate of the region exhibited significant seasonal variations, with temperatures ranging from 11°C in winter to 27°C in summer. The collected data were analyzed based on the phenological stages of the trees, allowing for the assessment of parasitoid richness and diversity. The study recorded 1.484 individuals distributed across five families and 16 genera, with abundance varying across tree development stages. Anagrus atomus (Mymaridae) was predominant during shoot and inflorescence development, while Scelionidae sp and Trissolcus basalis (Scelionidae) dominated during fruit development, maturation, and senescence. The theoretical estimation of species richness suggests that over 90% of the expected species were captured. Spearman correlation analyses revealed that T. basalis and Scelionidae sp. are positively influenced by temperature and negatively affected by humidity, highlighting the significant impact of climatic conditions on their abundance and distribution.