Compatibility of entomopathogenic fungi and imidacloprid (Confidor®) on biological characteristics and life table of Diaeretiella rapae (Hymenoptera: Braconidae), a parasitoid of Brevicoryne brassicae (Hemiptera: Aphididae)

Brevicoryne brassicae L., better known as the cabbage aphid, is a significant pest of the Brassicaceae family. This study aimed to investigate the compatibility of entomopathogenic fungi (EPF), namely Acremonium sclerotigenum FCCUU490 and Lecaniciliium muscarium FCCUU420, with imidacloprid (Confidor®), on the biological characteristics and life table of Diaeretiella rapae (Hymenoptera: Braconidae), a parasitoid of Brevicoryne brassicae (Hemiptera: Aphididae). Results showed that the percentage germination of conidia in A. sclerotigenum and L. muscarium did not differ significantly between combination treatments and the control, which indicates imidacloprid did not affect fungi germination. The oviposition period of D. rapae exposed to imidacloprid (LC₂₅ = 9.2 ppm) was 2.73 d, the lowest one among treatments, and the best one was for L. muscarium (LC_12.5 = 1.4 × 10¹ conidia ml⁻¹) plus imidacloprid (LC_12.5 = 5.5 ppm). Imidacloprid had the most negative effects on all the tested parameters. A. sclerotigenum and L. muscarium had the least negative effect on D. rapae. Female adults had 3.6 d long life in mixed (L. m. and Imid) treatment in comparison to imidacloprid with 2.8 d. The life expediency (e_xj) of imidacloprid was the lowest for females among the treatments. Considering the significance of sublethal effects of EPF and imidacloprid on D. rapae, the use of these two EPF alone or in combination with sublethal concentrations of imidacloprid in integrated management of cabbage aphids is recommended. According to the parameters of the life table of these two EPF alone or in combination with sublethal concentrations of imidacloprid that had the lowest side effect on D. rapae, the use of these treatments in integrated management of cabbage aphids is recommended.