Insecticidal Effects of Essential Oils against Nymphal and Adult Stage of Ricania simulans (Hemiptera: Ricanidae)

Abstract

Ricania simulans (Walker, 1851) (Hemiptera: Ricanidae) nymphal and adult stages prefer all agricultural plants, bushes and young trees as their hosts, and feed on the juice of these plants and damage them areas in the Eastern Black Sea coastline since 2006. Nymphs have 5 nymphal stages and emerge in the end of May. The adults emerge early July and start to lay their eggs in early August, overwinter egg stage and gives one generation in a year. Nymphal and adult stages of R. simulans were tested against the toxicities of essential oils obtained from six plant species ( Achillea biebersteinii Afan. (Asteraceae), Origanum onites L. (Lamiaceae), Rosmarinus officinalis L. (Lamiaceae), Salvia pratensis L., (Lamiaceae), Satureja hortensis L. (Lamiaceae) and Tanacetum balsamita L. (Asteraceae)). In comparison with the control group (Ethanol+ Sterile water mix), six different plant essential oils showed an insecticidal effect against the nymphal and adult stage of R. simulans, while Neemazal was used as positive control group. It was shown that mortality of the nymphs of R. simulans increased significantly after the treatment with essential oils (P≤0.05). The essential oils were dissolved in DMSO water solution (Ethanol+ Sterile water mix), and were sprayed to adults and nymphs at 10, 15 and 20 μL/petri doses respectively. However, the mortality increased with the increment of exposure time. After an exposure of 96 h at the concentration of 20 μL/petri dish, mortality rates of R. simulans nymphal and adult stages were reported as 42.5–74.1% and 23.3–50.8%, respectively. At the end of 24 hours, the doses of 10, 15, 20 μL/petri were reported to be the most effective in 8.33% mortality of essential oil R. officinalis R. simulans nymphal stage. Similarly, 26.6, 47.5, 74.1% mortality rates was seen after 48, 72 and 96 h with the application of volatile oil of R. officinalis respectively. Positive control (Neemazal) have highest mortality rates for nymphs (98.7%) and adults (70.0%).