Efficacy of Certain Insecticides for Controlling the Two Spotted Spider Mite, Tetranychus urticae (Koch) and Determination Residues of Abamectin on Some Quality Parameters of Cucumber Fruits

Abstract

Field trials were conducted in El-Salhia, Sharkia governorate, to assess the effectiveness of insecticides (imidaclopride, lambdacyhalothrin, and abamectin) against the two-spotted spider mite, Tetranychus urticae, on cucumber crops. The trial used a randomised complete block design (RCBD) with three treatments: T1: abamectin, T2: lambda-cyhalothrin, T3: imidaclopride, and control, which was repeated three times. At varied harvest intervals of (2h), 1, 3, 5, 7, 9-, 11-, 13-, and 15days following insecticide applications, residues and abamectin dissipation were measured. The insecticide's persistence, dissipation, half-life value, and safe harvest interval in cucumber were estimated. Additionally, the effects of abamectin residues on various quality indices (total soluble sugars, glucose, acidity, total soluble solids, ascorbic acid, -carotene, dry matter, and protein) were assessed in the last three samples (7 and 15 days after applications). The results revealed that all the treatments reduced the two-spotted spider populations. Furthermore, the results showed that the treatments sprayed with abamectin gave the highest reduction percentage (96.32%), followed by lambda-cyhalothrin (92.22%) and imidaclopride (76.93%). The halflife (t12) values in cucumber fruits were 2.99 days, and the loss percentages of initial deposits in cucumber fruits were 8.96 mg/ kg. In conclusion, we encourage farmers to use abamectin according to the Ministry of Agriculture recommendation in combating T. urticae, in integrated pest management, as cucumbers can be safely consumed after 7 days of abamectin treatment.