Predatory mites associated with Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae) on native solanaceous plants of coastal Pernambuco State, Brazil

Abstract

The occurrence of the tomato red spider mite (Tetranychus evansi Baker & Pritchard) and predatory mites on four of the most abundant native solanaceous plants in coastal Pernambuco, Brazil, was evaluated. Monthly samples were collected from mid September 2002 to late May 2003 in Aliança, Carpina, Camaragibe, Goiana, Igarassu and Recife. A total of 5,485 mites of more than 27 species were found, of which the most common were the phytophagous species T. evansi and Brevipalpus phoenicis (Geijskes) (Tenuipalpidae), and the predaceous species Asca sp. (Ascidae), Phytoseius guianensis De Leon and Paraphytoseius orientalis (Narayanan, Kaur & Ghai) (both Phytoseiidae). Negative indexes of association were determined between T. evansi and each of four species of predaceous phytoseiids [i.e., the three most numerous species found in this study as well as Phytoseiulus macropilis (Banks)]. Laboratory tests were also conducted to evaluate the acceptability of Tetranychus urticae Koch and T. evansi as prey by the four predatory species. Only P. macropilis survived and oviposited well when fed T. urticae. Although they were able to remain alive for some days when fed T. evansi, the reproduction levels of the four predator species were very low. These results suggest that despite being commonly found on solanaceous plants in the field, these predators feed very little or do not feed at all on T. evansi in nature.