Effect of Hexaflumuron and Spirodiclofen on Demography of Hipodamia variegata (Goez)(Col:Coccinellidae) Predator of, Agonoscena pistaciae Burckhardt and Lauterer Under Laboratory Conditions

Document Type : Research Article

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Abstract

The Lady beetle, Hippodamia variegata is one of the natural enemies of Agonoscena pistaciae. Demographic toxicology is a common method for evaluating sublethal effects of insecticides on natural enemies. Regarding to use of hexaflumuron and spirodiclofen in pistachio gardens, present study conducted to evaluate the side effects of the pesticides on demographic parameters of H. variegata under controlled conditions (26 ±10C, 65±5% RH and 16:8h L:D). For this purpose, 120 fresh eggs were treated with field recommended concentration of insecticides and treated into Petri dishes 6 cm with distilled water was used as control, by dipping method. Results has shown that there were significant differences among treatment for gross reproductive rate (GRR), net reproductive rates (R0), intrinsic rate of increase (rm), finite rate of increase (ג), intrinsic birth rate (b) and doubling time (DT) parameters. The gross reproduction rates were estimated 24.43±0.38, 55.67 ±0.49 and 48.11±0.66 in hexaflumuron, spirodiclofen and control respectively. In addition, rm were estimated 0.086±0.0067, 0.1086±0.0045 and 0.1232±0.007, Moreover, DT values were recorded as 8.62±0.51, 6.54±0.25 and 5.88±0.29 as above mentioned, respectively. According to this experiments, hexaflumuron had higher negative effect on intrinsic rate of H. variegata and it will be suggested that to be considered in integrated pest management.

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