Effect of Nanoformulation on toxicity of some herbal extracts against two-spotted spider mite Tetranychus urticae and Silverleaf whitefly Bemisia tabaci

The present study was designed to evaluate the lethal effects of aqueous extracts and nanoformulations of Rosmarinus officinalis L., Lavandula angustifolia Mill., Eucalyptus globulus Labill. and Artemisia dracunculus L. on Tetranychus urticae Koch (female and male adults) and Cuminum cyminum L. and Coriandrum sativum L. on Bemisia tabaci (Gennadius) (first and third instar) under laboratory conditions at 25 ± 2 ºC, 60% RH, and 16:8 h. photoperiod using contact toxicity method. Among aqueous and formulated extracts rosemary (LC50 = 3227 ppm) and tarragon (LC50 = 1454 ppm) had the highest toxicity against adult mites, respectively. Aqueous and formulated extracts of cumin also showed the highest toxicity with LC50 of 9639 and 6748 ppm on the first instar and 11670 and 9937 ppm on the third instar of B. tabaci, respectively. The first instar of B. tabaci showed more sensitivity to aqueous and formulated extracts than third ones. Based on the results of high-performance liquid chromatography (HPLC), Salcillic acid for rosemary (21.68%), lavender (33.90%) and coriander (9.9%), and quercetin for eucalyptus (76.62%), tarragon (23.49%) and cumin (15.68%) had the highest amount of chemical compounds. Our findings show the reliable toxicity of plant extracts and will facilitate the use of plant products in integrated pest management programs under greenhouse conditions.