Fumigant toxicity of Carum copticum L. (Apiaceae) essential oil on Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) adults under greenhouse conditions.

摘要

Greenhouse whitefly Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) is one of the most injurious pests of greenhouse crops and ornamental plants in worldwide, both outdoor and indoor. This insect, feeding on plant sap, producing honeydew and transmitting plant viruses, causes quantitative and qualitative damages in plants. For controlling this pest in greenhouse, plant essential oils are mentioned instead of chemical insecticidal. So, in this research, fumigant toxicity of Carum copticum L. (Fam.: Apiaceae) plant oil on mentioned adult pest was surveyed. Dry ground seeds were subjected to hydrodistillation using a modified Clevenger-type apparatus and the resulting oil contained Thymol (50.07%), Gama-Terpinene (23.99%), P-Cymene (22.9%), Myrcene (0.51%) and 1,8-Cineole (0.5%). All bioassay tests were conducted at 27+or-2 degrees C, 65+or-5 RH and a photoperiod of 16:8 h (light: dark). This research was performed with a completely random design with six treatments (five different concentrations of essential oils plus control). Each concentration includes of three replicates and each replicate consisted of 20 adult of pests. The results showed that aforementioned essential oil shows significant mortality of adults 24 h after exposure. The value LC₅₀ of mentioned plant oil on T. vaporariorum was 1.03 micro l L/L air. And mortality percentage shows higher sensitivity of T. vaporariorum against application of essential oil. The value LT₅₀ estimated for T. vaporariorum in concentration of 1.03 micro l L/L air was 7.18 h. Fumigant toxicity this essential oil has had an ordered relationship with the concentration and time exposure. The results of this research showed that mentioned plant oil had appropriate insecticidal effects on these greenhouse pests. The findings showed that C. copticum L. oil has high impact on the above-mentioned pests and it is suggested because of its high potential in fumigant toxicity and its use in integrated pest management programmes in greenhouses is mentioned.