Acaricidal Activity of Some Natural Products on the Two-Spotted Spider Mite, Tetranychus urticae in Laboratory

Abstract

Two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) is a great economic importance in Egypt that causing considerable damage to many crops. Some silicon formulations as kaolin, bentonite, aglev Si 300 & diatom as powder formulations, different forms of liquid formulation for potassium silicate and palmito formulation (plant extracts) as standard, were examined against Tetranychus urticae under laboratory conditions. The toxicity effect on adult females was determined. Also, acaricidal effects on some biological aspects of Tetranychus urticae were studied. The results demonstrated that the percentage of mortality increased as the concentration increase. palmito, diatom and kaolin gave the highest mortality rates followed by aglev Si 300, while the least effect found in bentonite on T. urticae adult females. The obtained results revealed that the best treatment for the rate of laying eggs at 100 % concentration was potassium salt for liquid formulations, diatom and aglev Si 300 for powder formulations. In general, liquid formulations were more effective on the oviposition rate for treated females than powder formulations. In egg incubation treatment, kaolin (100% conc.) gave the longest incubation period with an average (4.8 days), while the lowest average (3.4 days) was recorded with bentonite (75% conc.), which is the same rate as was found in the control. The best treatment for the egg hatch rate was bentonite (100% conc.), while the least effect was recorded with Kaolin (50% conc. Accordingly to the results of egg period, the best treatments were si El-Ghanem (100% conc.), bentonite (100% conc.), bentonite (75% conc.) and aglev Si 300 (100% conc.). The best
treatments of larva period were bentonite (100% conc.), aglev Si 300 (100% conc.), diatom (100% conc.) and diatom (75% conc.). The present study revealed that some silicon formulations, such as diatom, kaolin, aglev Si 300, si El-Ghanem, kaolinated potassium silicate and potassium salt can be used alternatively as acaricides for potential mite management in integrated crop management.