Psoroptes ovis

Medición in vitro de la susceptibilidad y determinación de la resistencia relativa a acaricidas

Abstract

Groups of 110 ovigerous females from two strains of Psoroptes ovis (Hering) were dipped, confined in pairs of paper envelopes by means of a vacuum system, into a series of different concentrations of lindane, diazinon and pirimiphos ethil. They were kept at 35° C and 80-90 0/0 R.H. for 24 hours and the death rate was computed.

A strain (Facultad) was characterized according to lindane (LC50 =104.5 ppm; LCgg = 204.3 ppm); diazinon (LC50 =0.57 ppm; LCgg =0.98 ppm) and pirimiphos ethil (LC50 =0.13 ppm; LCgg =0.42 ppm), and used as a reference.

A relative resistance was diagnosed in a strain under research (Tranqueras) with the following factors of resistance: lindane 2,5; diazinon 69 and pirimiphos ethil 796.