Diversity and population dynamics of mites in peach and plum trees (Rosaceae) in the Southwest State of SAo Paulo, Brazil

Density and diversity of mites (Acari) among six peach and five plum cultivars were investigated in the State of SAo Paulo, Brazil. The trees were free of pesticides. Fortnightly mite samples, which consisted of the random collection of 30 leaves from the middle third of each cultivar, were taken from January 2004 to March 2006. A total of 42,900mites was collected, 5593 from plum (35 species in 27 genera and 17 families) and 37,307 from peach (32 species in 25 genera and 15 families) for a total of 42 species, 33 genera, and 20 families. The two-spotted spider mite Tetranychus urticae Koch was the most common species, followed by the Plum Rust/Peach Silver Mite Aculus fockeui (Nalepa and Trouessant) and the predator Euseius ho (De Leon). In total, 15 species of Phytoseiidae are reported for both crops. The Eriophyidae Aculus fockeui represented approximately 86% of all specimens recovered from peach leaves and was the most abundant in Ouromel 2' and Centenaria' peach and plum cultivar, respectively and their occurrence was verified during short periods in leaves of all cultivars. The population of T. urticae correlated positively with the average temperature in peach cultivars. In general, higher mite diversity was obtained on plum leaves, while greater abundance occurred on peach cultivars.