اثرات زیرکشندگی فلوبندیامید (تاکومی) روی پارامترهای تولیدمثلی و رشد جمعیت زنبور پارازیتوئید Habrobracon hebetor (Hym.: Braconidae)

Habrobracon hebetor Say (Hym.: Braconidae) is one of the most important ectoparasitoids of many important agricultural pests larval stage such as Noctuidae and Pyralidae family moth. The appropriate use of biological agents and chemical compounds is necessary to create successful integrated pest management (IPM) programs. Flubendiamide (Takumi 20% WG) is a contact-stomach insecticide with a pre-harvest interval of (PHI) 1 day. In this study, to estimate the sub-lethal concentrations (LC10, LC20 and LC30) of Flubendiamide, bioassay was performed by the leaf dip method. The obtained values for sub-lethal concentrations were 30, 47 and 65 (µg /L) and their confidence limits were (13.68 – 34.33), (27.66 – 51.95) and (45.04 -71.45), respectively. Then the sub-lethal effects of mentioned concentrations and the control were studied on biological parameters of this parasitoid wasp in laboratory conditions, at 25 ± 2 °C, and with relative humidity of 65 ±.5 % and a photoperiod of 16:8 (L:D) h. Thus, the 60 number of the same-aged eggs were collected and placed into a Petri-dish and then, they were treated with sub-lethal concentrations and the control. After the adult’s emergence, the number of offspring produced by each female was daily recorded until the death of the last individual. Data analysis was performed according to the Age-Stage Two Sex Life Table theory. The results showed that the intrinsic rate of increase (r), net reproductive rate (R0) and the gross reproductive rate (GRR) were significantly affected by sub-lethal concentrations. The lowest recorded value of the intrinsic rate of increase was 0.02 ± 0.01 (day-1) and for the net reproductive rate was 1.71 ± 0.62 (offspring) at LC30, and the estimated gross reproductive rate was 4.28 ± 1.02 (offspring) at LC10 which had a significant difference with other treatments. Values of the finite rate of increase (λ) and the mean generation time (T) were not affected by these sub-lethal concentrations. Our findings revealed that by increasing of the Flubendiamide concentrations, the negative effects of this pesticide on the life table parameters of H. hebetor increased significantly. Therefore, in order to have effective integrated pest management programs it is important to have the low concentrations of Flubendiamide being used in combination with this parasitoid wasp or the parasitoid get released within a reasonable time after the chemical control.