Toxicity and biological effects of chlorfluazuron on the cotton leafworm, Spodoptera littoralis (BOISD.) [electronic resource].

Includes references.

Chlortluazuron is an insect growth regulator used for controlling the major insect pests of several crops. The present work was conducted to study the susceptibility of laboratory strain of 51 h instar larvae of the cotton leaf worm, Spodoptera Jittoralis (Boisd.) to chlortluazuron using three methods of application. (topical application, injection and oral administration). Data showed that the topical method exhibited high level of toxicity with LD50 value (0.87 Jlg a.i. /larva) followed by injection (3.59 Jlg a.i. /larva) then oral method which recorded (13.20 Jlg a.i. /larva). Topical application caused a prolongation in larval duration, while injection and oral methods showed no significant differences in larval duration compared with the control. All methods of administration caused reduction in pupal weight and significant deformation percentages in larval and pupal stages, whereas topical application caused the highest percentage in larval and pupal deformation compared with the other methods and control. Topical application, also, caused a significant reduction in longevity of female moth, hatchability and sterility compared with the control. Meanwhile, oral and injection methods caused reduction in fecundity compared with the control, when 5th instar larvae of S. littoralis treated with sub-lethal dose (LD25) of chlortluazuron. The activity could be arranged as follows: topical application, injection and oral administration

Summary in Arabic.

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