Effect of wheat cultivars, with varying resistance levels to Rhyzopertha dominica, on life history parameters of the ectoparasitoid wasp Anisopteramalus calandrae

Abstract

The ectoparasitoid wasp Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae), as a widely distributed ectoparasitoid wasp, can parasitize several Coleopteran insect pests such as the lesser grain borer Rhyzopertha dominica (F.) (Coleoptera, Bostrichidae). In the current study, the plant-herbivore-parasitoid interactions with A. calandrae and R. dominica on six cultivars of wheat Triticum aestivum L. (Poals: Poaceae), including Aftab, Araz, Ghabos, Kalateh, Meraj, and Tirgan, were assessed. The largest egg and larval-pupal periods of R. dominica were observed on cultivars Tirgan and Aftab. Rhyzopertha dominica reared on cultivar Araz had the largest total developmental period. The highest oviposition period and fecundity of R. dominica were observed on cultivar Meraj. The pest had the brief life and the low fecundity duration on cultivar Tirgan. The longest developmental time of A. calandrae was observed on the cultivar Tirgan. The parasitic wasp lived longer on cultivar Ghabos. The developmental time of A. calandrae was positively affected by phenolic content of wheat cultivars. The fecundity and intrinsic rate of increase (r) of the parasitic wasp were significantly decreased by increasing the phenolic content of the cultivars. In general, the cultivar Meraj was sensitive, the cultivars Aftab and Kalateh were semi-resistant, and the cultivars Araz, Ghabos, and Tirgan were resistant to R. dominica. The cultivar Tirgan was found as an unsuitable host compared to others for performance of A. calandrae, while Aftab, Kalateh, Araz, and Meraj were suitable ones. Consequently, the use of cultivar Araz as a resistant host to R. dominica and the suitable cultivar to A. calandrae can be considered as an effective integrated management choice against the pest.