| Sublethal effects of Heracleum persicum L. herbal extract on demography parameters of two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae) under laboratory condition |
| Paper ID : 1075-3IICE (R1) |
| Authors: |
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Golamreza Golmohammadi *1, Mhammadreza Havasi2 1partment of entomology 2Department of Entomology and Plant Pathology, Aburaihan Campus, University of Tehran, Pakdasht, Iran |
| Abstract: |
| The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is a worldwide pest, causing economic damage to many species of crop plants. The use of chemical pesticides is one of the key ways to control this pest. However, application of chemicals are limited due to their destructive effects. For this purpose, botanical substances proved to be suitable alternatives. Therefore, in this study, sublethal effects of Persian Hogweed herbal extract (Heracleum persicum L.) including LC10, LC20, LC30 and distilled water were investigated on some biological parameters of T. urticae. Experiments were carried out at 25±2°C, 60±5% RH, and a photoperiod of 16:8 h (L: D). Developmental time and survivorship of all immature stages as well as adult longevity and fecundity were recorded every 24 h. Data were analyzed based on age-stage, two-sex life table analysis. Three sublethal concentrations were determined based on dose-response bioassay as 1750, 2450 and 3200 ppm, respectively. Results demonstrated that by increasing the experimental dose from LC10 to LC20 and LC30, a significant decline was observed in duration of biological maturation for both sexes of two-spotted spider mite. Furthermore, the total fecundity rate was calculated, as 61.1, 51.02, 42.45 and 35.3 offspring/individual in control, LC10, LC20 and LC30 treatments, respectively. The intrinsic rate of increase (r) ranged between 0.1812 and 0.2201 day-1 for the mites treated at LC20 and control treatments, respectively. Similarly, finite rates of increase were 1.017 and 1.246 day-1 for LC20 and control treatments, respectively. The maximum and minimum values of gross reproductive rate (GRR) were recorded as 48.34 (offspring) at control and 20.21 (offspring/individual) in LC20 concentration. The mean generation time (T) varied from 14.17 up to 16.55 days in control and LC20 concentrations. The highest and lowest lifespan periods of the female T. urticae, were 23.53 and 18.84 days which belonged to control and LC20 treatments, respectively. Based on the obtained results, although application of sublethal concentrations of Heracleum persicum L. herbal extract had an impact on some biological parameters of T. urticae, complementary studies are necessary before recommending the extract in management of the pest. |
| Keywords: |
| Life table, Heracleum persicum, sub-lethal effects, Tetranychus urticae, Herbal extract |
| Status : Paper Accepted (Poster Presentation) |
