›› 1996, Vol. 39 ›› Issue (4): 342-346.

• RESEARCH PAPERS • Previous Articles     Next Articles

STABILITY OF PYRETHROIDS RESISTANCE IN HELICOVERPA ARMIGERA (HUBNER)

Wu Yidong Shen Jinliang Tan Fujie You Ziping   

  • Online:1996-11-20 Published:1996-11-20

Abstract: Regression of pyrethroids resistance in Helicoverpa armigera (Hubner)following several generations of insecticide-free laboratory rearing was evaluated.Although laboratory selected Fen-R strain had extremely high level resistance to fenvalerate (3 166.3 fold), the resistance was unstable and decreased to 61.4 fold after14 generations when selection was suspended. Studies on several field-collected cotton bollworms resistant to pyrethroids (fenvalerate, deltamethrin & cyhalothrin) showed that their resistance was also unstable; it declined rapidly without contact with the pyrethroids at first and then stablized at a 2- 9 fold level. It seemed very difficult to recover susceptibility completely to the three pyrethroids.

Key words: Helicoverpa armigera (Hubner), pyrethroids, resistance stability