Toxicity of botanical insecticides on different species of lace bugs

This study aimed to evaluate the toxicity of essential oils (EO) from Allium sativum (Amaryllidaceae) and Eucalyptus citriodora (Myrtaceae), commercial oil (CO) from Azadirachta indica (Meliaceae), and ethanolic extracts (EE) of Eugenia caryophyllata (Myrtaceae) and Piper nigrum (Piperaceae) on lace bugs (Hemiptera: Tingidae). The study also investigated the effects of exposure method, surfactant addition, and lace bug species on insecticide toxicity. The results indicated that assessing lace bug toxicity via contact with contaminated filter paper is a more effective method. Adding 5% detergent to E. citriodora EO 1% increased the mean mortality rates of the lace bug Gargaphia lunulata and Corythaica passiflorae from 34.11% to 94.00%. A. sativum EO 10%, E. citriodora EO 1%, and A. indica CO 1%, when combined with 5% detergent, caused high mortality rates in G. lunulata (76.00%, 77.67%, and 80.73%, respectively). However, these insecticides without detergent caused lower mortality in C. passiflorae (15.44%, 20.09%, and 11.15%, respectively), highlighting the significant impact of surfactant addition on the toxicity of essential and commercial oils. Piper nigrum EE 10% was toxic to all lace bug species. Conversely, the toxicity of Eugenia caryophyllata EE 10% varied among species, with mortality rates of 40% in G. lunulata, an average of 76.00% in Ulotingis sp. and Vartiga illudens, and 95.48% in C. passiflorae. In conclusion, despite variations in toxicity due to exposure method, surfactant addition, and lace bug species in laboratory bioassays, the botanical insecticides studied show promise for lace bug control.