Disturbing Effects of the Chitin Synthesis Inhibitors, Novaluron and Diofenolan, on the Phosphatase Activity in the Pink Bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae).

Document Type : Original Article

Authors

Department of Zoology and Entomology, Faculty of Science, Al-Azhar University, Madenit Nasr, Cairo, Egypt.

Abstract

     The pink bollworm Pectinophora gossypiella is one of the most destructive insects attacking cotton fields worldwide. It acquired resistance against most of the conventional pesticides. Therefore, the present study was carried out aiming at the investigation of disturbing effects of Novaluron (LC50: 0.765 ppm) and Diofenolan (LC50: 0.036 ppm) on the phosphatase activity in homogenates of larvae (6 hr post-treatment) as well as in early- aged pupae (1-day old), mid-aged pupae (3-day old) and late-aged pupae (7-day old), after treatment of full-grown larvae. After treatment with Novaluron and Diofenolan, both compounds enhanced the larvae to attain remarkably elevated acid phosphatase activity (ACP). In the pupae, ACP activity was predominantly promoted by both compounds, regardless the age. The Alkaline phosphatase(ALP) activity was tremendously declined in the treated larvae. Novaluron enhanced pupae to gain slightly or considerably increasing activity, regardless the age. On the other hand, Diofenolan exhibited a diverse effect since the enzyme activity was pronouncedly declinedin the early-aged pupae but remarkably enhanced in the mid- and late-aged pupae.

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