Management of phytophagous mites in European vineyards

Abstract

The first infestations of spider mites in European vineyards were detected in the second half of the nineteenth century after the invasion of powdery mildew, downy mildew and phylloxera from North America. Serious problems associated with Tetranychus urticae Koch were detected in Italy and Austria and local outbreaks of Panonychus ulmi (Koch) were recorded. At that time the eriophyid Colomerus vitis (Pagenstecher) was known but not considered important, probably because sulfur was largely used to control grape diseases. Two additional species were described at the beginning of the twentieth century: the spider mite Eotetranychus carpini (Oudemans) and the eriophyid Calepitrimerus vitis (Nalepa). At that time, problems with mites injurious to grapes were negligible but the situation suddenly changed after World War II. Most of these problems were immediately associated with the extensive use of chlorinated hydrocarbon insecticides and later, by ethylene-bis-dithiocarbamate fungicides (EBDC). Three spider mite species were involved in the outbreaks: E. carpini, P. ulmi and T. urticae (Rambier 1958; Rota 1962; Zangheri and Masutti 1962). Most researchers of the time thought that mite outbreaks were due to the detrimental effects of pesticides on natural enemies of spider mites. However, there was little evidence to support this fact. Meanwhile, according to Chaboussou (1965) infestations were caused by changes in plant physiology induced by organic pesticides, favorable to mite demographic parameters ('trophobiosis'). Chaboussou (1965) and others also tried to classify the most common pesticides according to their effect on spider mites. However, contradictory results were reported and no scientific proof could be obtained, and trophobiosis remained a matter of great debate among entomologists.