M. Nikooei - Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, P. O. Box: ۱۴۱۱۵-۳۳۶, Tehran, Islamic Republic of Iran.
Y. Fathipour - Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, P. O. Box: ۱۴۱۱۵-۳۳۶, Tehran, Islamic Republic of Iran.
M. Jalali Javaran - Department of Plant Breeding, Faculty of Agriculture, Tarbiat Modares University, Tehran, Islamic Republic of Iran.
M. Soufbaf - Agricultural, Medical and Industrial Research School, P. O. Box: ۳۱۴۸۵-۴۹۸, Karaj, Islamic Republic of Iran.

Plant quality in herbivores’ diet may affect the performance of both herbivore and its parasitoids. In the present research, parasitism capacity of Diadegma semiclausum (Hellen) on Plutella xylostella (L.) reared on different genetically manipulated Brassica plants including the canola’s progenitor (Brassica rapa L.), two cultivated canola cultivars (Cultivar-Opera and Cultivar-RGS۰۰۳), one hybrid (Hybrid-Hyula۴۰۱), one gamma mutated (Mutant-RGS۰۰۳), and one transgenic (Transgenic-PF) genotype was determined. All experiments were carried out in a growth chamber at ۲۵±۱˚C, ۶۵±۵% RH, and a photoperiod of ۱۶:۸ (L: D) hour. The value of the net parasitism rate (C۰) of D. semiclausum was ۱۴.۹۴, ۲۰.۱۲, ۱۴.۹۵, ۱۲.۲۰, ۱۳.۹۴, and ۱۲.۵۵ hosts on B. rapa, Cultivar-Opera, Cultivar-RGS۰۰۳, Hybrid-Hyula۴۰۱, Mutant-RGS۰۰۳, and Transgenic-PF, respectively. The transformation rate from host population to parasitoid offspring (Qp) on all genotypes was close to ۱ (C۰ R۰). Moreover, the value of the finite parasitism rate  was ۰.۲۷۱, ۰.۲۸۵, ۰.۲۷۷, ۰.۲۰۲, ۰.۲۰۵, and ۰.۲۰۲ host parasitoid-۱ day-۱ on the above-mentioned genotypes, respectively. The finite parasitism rate considers the finite rate of increase, the stable age-stage distribution, and the age-stage specific parasitism rate; therefore, this parameter could be used to assess the efficiency of a parasitoid. In conclusion, D. semiclausum had higher parasitism capacity on canola’s progenitor and the cultivated genotypes which were more suitable for parasitoid’s host based on secondary metabolites concentration.

Diamondback moth, Finite parasitism rate, Manipulated canola, Plant chemistry, Two-sex parasitism