Sublethal effects of pyriproxyfen on some biological and biochemical properties of elm leaf beetle, Xanthogaleruca luteola (Col.: Chrysomelidae)

Abstract

The lethal and sublethal effects of pyriproxyfen (a juvenile hormone analogue) were investigated on feeding deterrence, growth and larval weight as well as enzymatic and non-enzymatic activities of the third instar larvae of elm leaf beetle, Xanthogaleruca luteola Müller. The LC30 and LC50 values were estimated to be 133 and 343 ppm per larvae after 72 hours, respectively. Due to the treatment with 133 and 343 ppm of pyriproxyfen, feeding deterrence and prolongation in larval duration were observed. Also, the amounts of total protein, glucose, glycogen, urea, acid phosphatase and α-amylase activities were significantly decreased in the treated specimens compared with the controls. On the other hand, alanine aminotransferase activity and cholesterol levels were increased in the specimens 72 hours after the treatment compared with the controls. There were significant differences in the amount of uric acid and the activity of alkaline phosphatase, glutathione S-transferase and esterases compared with the controls. Present results showed that pyriproxyfen caused some biological and physiological discrepancies in the survived insects after treating with LC50 concentration of the insecticide which indicates changes in the metabolism of these compounds. Hence, it seems that pyriproxyfen has the potential to be used as a biorational insecticide in the integrated pest management (IPM) program for X. luteolla.

Keywords

• xanthogaleruca luteola
• pyriproxyfen
• sublethal effects
• enzymatic and non
• enzymatic changes
• juvenile hormone mimic