Laboratory bioassays were carried out on two species of phytoseiid mites to investigate their resistance to the fungicide mancozeb. Susceptible and suspected resistant strains ofKampimodromus aberrans(Oudemans) andTyphlodromus pyriScheuten were tested. Mancozeb resistance factors were low to moderate: they reached 6.3 and 11.7 forK. aberransandT. pyri, respectively. Intrinsic toxicity of mancozeb was approximately 5–10-fold more pronounced in females ofK. aberransthan in females ofT. pyri. The female susceptibility pattern of the most resistant strain ofK. aberranswas quite close to that of the most susceptible strain ofT. pyri. The LC50values for the most resistant strains ofK. aberransandT. pyriwere 4.6 and 43 times higher, respectively, than the maximum field application rate of mancozeb recommended for control of downy mildew in vineyards. Using a diagnostic concentration, a limited survey in vine plots indicated that most of theK. aberransstrains we tested were susceptible to mancozeb, but a few consisted of both resistant and susceptible individuals. All strains ofT. pyricollected in Burgundy were susceptible. Half of theT. pyristrains from Bordeaux were susceptible and the other half were mixed populations of resistant and susceptible individuals.
No takes yet. Share an insight, caveat, or question.
Auger et al. (2004) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: