Experimental & Applied Acarology

, Volume 6, Issue 1, pp 29–46

Resurgences of spider mites (Acari: Tetranychidae) induced by synthetic pyrethroids

  • Uri Gerson
  • Ephraim Cohen
Article

DOI: 10.1007/BF01193231

Cite this article as:
Gerson, U. & Cohen, E. Exp Appl Acarol (1989) 6: 29. doi:10.1007/BF01193231

Abstract

Causes of spider mite (Acari: Tetranychidae) population resurgences consequent upon exposure to synthetic pyrethroid (SP) treatments are reviewed. Resurgences may be seen as soon as 1 week, or even as late as a whole season, post-treatment. Synthetic pyrethroids vary in their adverse effects on spider mites, and also differ in their ability to invoke resurgences of different spidermite species on diverse plants. These pesticides are lethal as well as repellent to phytoseiids and other predators that prey on spider mites, may inhibit fungi which attack the latter, and affect phytophagous competitors. Spider mites are likewise repelled by SPs, thus becoming more evenlydistributed and less web-restricted, with a resultant increase in fecundity. Spider-mite development is shortened due to SPs and the sex ratio becomes more female-biased; onset of winter diapause also seems to be delayed. Synthetic pyrethroids appear to sensitize to spider-mite infestation plants which have not hitherto been attacked. Some SP effects (whether on spider mites, natural enemies or competitors) appear to be direct, whereas others may be mediated through the host plants. The effect of SPs on the other Acari is variable within the Prostigmata and Astigmata. Most Mesostigmata and Metastigmata (ticks) are very sensitive, whilst the Cryptostigmata (Oribatei) appear to be insensitive. Synthetic pyrethroids-induced resurgences of Homoptera are comparatively reviewed, with the conclusion that some of the phenomena may be similar to those observed in spider mites. Various resurgence models are discussed, as well as the three main causes of variation (SPs, spider-mite species, host plants) in the observed phenomena. The need for more rigorous and carefully controlled experimentation is emphasized.

Copyright information

© Elsevier Science Publishers B. V. 1989

Authors and Affiliations

  • Uri Gerson
    • 1
  • Ephraim Cohen
    • 1
  1. 1.Department of EntomologyHebrew University of Jerusalem, Faculty of AgricultureRehovotIsrael