The cabbage aphid, Brevicoryne brassicae (L.), is one of the major insect pests of cole crops in Iran. In most instances outbreaks are normally kept under control by application of insecticides. In this study, the sublethal effects (LC30) of three insecticides, acetamiprid, buprofezin, and thiamethoxam-lambda cyhalothrin, (TLC) were evaluated on the population growth rate of the progeny of insecticide-treated cabbage aphid adults. The age-stage, two-sex life table method was used to analyze the collected data. The results indicated that the insecticide applications affected the duration of the preadult period, their survival, reproduction, life span/longevity, and consequently, the population growth rate of the F1 generation. The indicators of the greatest sublethal effects were noted in the progeny of the TLC-treated adults. These included the lowest net reproductive rate (R0), intrinsic rate of increase (r), finite rate of increase (λ), and the longest mean generation time (T). The highest values of r, λ, R, and the lowest value of T occurred in the control group followed by, in order, the acetamiprid and buprofezin groups. These research findings will be useful in the development and implementation of future aphid management programs.

Abstract:Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) is one of the most harmful, world-wide known pests of greenhouse crops and ornamental plants. This insect feeds on plant sap, produces honeydew, and transmits plant viruses, while causing quantitative and qualitative damage to plants. For controlling this pest in greenhouses, plant essential oils are used as an alternative to chemical insecticidal. So in this study, fumigant toxicity of Petroselinum crispum L. (Apiaceae) plant oil on the abovementioned adult pest was investigated. Dry seeds were ground and subjected to hydrodistillation using a modified Clevenger-type apparatus and the resulting oil contained myristicin (42.65%), β-phellandrene (21.83%), p-1,3,8-menthatriene (9.97%), and β-myrcene (4.25%). All bioassay tests were conducted at 27±2°C, 65±5% relative humidity (RH) and at a photoperiod of 16 : 8 h (light : dark).This research was performed in a completely randomised design with six treatments (five different concentrations of essential oils plus the control). Each concentration included three replicates and each replicate consisted of 20 adult pests. The results showed that the aforementioned essential oil showed significant mortality of adults 24 h after exposure. The value LC 50 of the mentioned plant oil on T. vaporariorum was 2.41 µl/l air. And mortality percentage showed higher sensitivity of T. vaporariorum against the application of the essential oil. The value LT 50 estimated for T. vaporariorum in a concentration of 2.41 µl/l air was 8.17 h. The fumigant toxicity of this essential oil had an ordered relationship with the concentration and time exposure. The results of this research showed that the mentioned plant oil had appropriate insecticidal effects on these greenhouse pests. The findings showed that P. crispum oil had a high impact on the above-mentioned pest, and its use is suggested because of its high potential fumigant toxicity. The oil of P. crispum may be used in integrated pest management programmes in greenhouses.

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