اثر تیمار گیاه فلفل رنگی با جاسمونیک اسید و قارچ Trichoderma harzianum T22 بر پرانسجه‌های جدول زندگی تریپس غربی گل

The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is one of the most important greenhouse insect pests with a wide host range. Jasmonic acid (JA) is one of the main plant hormones derived from linoleic acid. This compound, as an endogenous plant regulator, improves the quantity and quality of the crop and increases resistance to environmental factors in particular, insect pests. Trichoderma spp. is one of the soil hyphomycetes that can be found in most agricultural soils. Trichoderma harzianum Rifai (Th) has received much attention due to its high reproduction capacity, high tolerance, and resistance to environmental stresses and pathogens. In this study, the effect of treated bell peppers (Lorca variety) with jasmonic acid (0.5 mm, synthesized by Sigma Aldrich), Trichoderma harzianum T22 (10 ml per plant from 107 spore/ml suspension, prepared from Biorun company) and the combination of jasmonic acid with T. harzianum (JA + Th) was investigated on the life table parameters of F. occidentalis. Eighty larvae from a cohort were selected and each larva was considered a replicate. The different life stages of F. occidentalis were monitored daily and their survival recorded until adults emerged. After the adult emergence, the females were placed individually on the host plant leaves and were checked each day until the adult’s death. The data were calculated based on the age-stage, two-sex life table theory using TWOSEX-MSChart program 2019. The experiment was carried out in constant environmental conditions (25±1°C, 65±5% RH, and 16:8 h light: dark). Based on the results, all life table parameters of F. occidentalis showed a significant difference. The intrinsic rate of increase (r) for control, JA, Th, and JA + Th treatments was estimated as 0.1827, 0.1513, 0.1636, and 0.1332 (day-1), respectively. The net reproductive rate (R0) for the mentioned treatments was calculated 53.22, 32.72, 38.99, and 25.62 (eggs/individual). Also, the highest and lowest values of the finite rate of increase (λ) were recorded for JA+Th (1.142 day-1) and control (1.200 day-1), respectively. The mean generation time (T) varied from 21.75 to 24.34 days for the control and JA+Th, respectively. The results of this study can be used in the application of JA+Th treatment for integrated management programs of F. occidentalis; However, it is recommended to conduct field studies, especially in greenhouse conditions, to prove its practical application.