Influence of Genetically Manipulated Brassica Genotypes on Parasitism Capacity of Diadegma semiclausum Parasitizing Plutella xylostella
J. Agr. Sci. Tech
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-RGS003), one hybrid (Hybrid-Hyula401), one gamma mutated (Mutant-RGS003), and one transgenic (Transgenic-PF) genotype
... genic-PF) genotype was determined. All experiments were carried out in a growth chamber at 25±1˚C, 65±5% RH, and a photoperiod of 16:8 (L: D) hour. The value of the net parasitism rate (C0) of D. semiclausum was 14.94, 20.12, 14.95, 12.20, 13.94, and 12.55 hosts on B. rapa, Cultivar-Opera, Cultivar-RGS003, Hybrid-Hyula401, Mutant-RGS003, and Transgenic-PF, respectively. The transformation rate from host population to parasitoid offspring (Qp) on all genotypes was close to 1 (C0≅ R0). Moreover, the value of the finite parasitism rate () was 0.271, 0.285, 0.277, 0.202, 0.205, and 0.202 host parasitoid-1 day-1 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.