Genetically manipulated Brassica genotypes affect demography and performance of Diadegma semiclausum parasitizing Plutella xylostella

Abstract

The performance of Diadegma semiclausum (Hellen) (Hymenoptera: Ichneumonidae) on Plutella xylostella (L.) (Lepidoptera: Plutellidae) reared on canola's progenitor (Brassica rapa L.), two cultivated canola cultivars (Opera and RGS 003 ), one hybrid (Hyula 401 ), one gamma-ray mutant-RGS 003 and one transgenic (PF) genotype was compared using the agestage, two-sex life table parameters. All experiments were carried out in a growth chamber at 25 AE 1°C, 65 AE 5% RH and a photoperiod of 16 : 8 (L : D) h. There were significant differences in duration of different life stages of D. semiclausum on its host larvae reared on different plant genotypes. The shortest (12.27 days) and longest (15.21 days) pre-adult developmental times were observed on cultivar-RGS 003 and hybrid-Hyula 401 , respectively. The intrinsic rate of increase (r) in D. semiclausum ranged between 0.189/day (cultivar-Opera) and 0.141/day (transgenic-PF). Moreover, the highest (20.078 offspring) and lowest (12.027 offspring) net reproductive rates (R 0 ) were observed on cultivar-Opera and hybridHyula 401 . The mean generation time (T) of D. semiclausum was the highest (18.34 days) and lowest (15.05 days) on mutant-RGS 003 and cultivar-RGS 003 . The maximum and minimum parasitism values of this parasitoid were observed on canola's progenitor (44.28%) and hybrid-Hyula 401 (37.09%). The heaviest pupae (3.82 mg) and females (3.22 mg) of the parasitoid were found on canola's progenitor and cultivar-Opera, respectively. The results showed that performance of this parasitoid was better on canola's progenitor and cultivated plants known to have higher levels of glucosinolates concentration than others.

Age stage, two-sex life table ofHabrobracon hebetor(Braconidae) onSpodoptera exigua(Noctuidae) reared on different sugar beet genotypes

“…For example, the natural enemies satisfy plants by reducing herbivore density and plants make herbivores more vulnerable to serve natural enemies (Ahmad et al, 2004). Although, the role of natural enemies in reducing herbivores population has been demonstrated by many researchers, in most systems both the quantity and nutrient quality of host-plant resources are also likely to be important bottom-up factors (Nikooei et al, 2015(Nikooei et al, , 2017Karami et al, 2018aKarami et al, , 2018b. Both latter factors can influence herbivore populations by altering their feeding preference and performance (Waring and Cobb, 1992).…”

Cascading effects of soil organic and inorganic fertilizers on tri‐trophic interactions: Plant–aphid–parasitoid wasp as a study system

“…The study of tri-trophic interactions is important for understanding natural species interactions and to manipulate these interactions in pest control. To develop a successful biological control programme, it is important to analyse the tri-trophic interactions among crop plants, the pest herbivores that attack them, and their main natural enemies (Nikooei et al, 2017).…”