Oligonychus ilicis (McGregor) is among those mite species that can cause damage to coffee plants (Coffea spp.). Species of Phytoseiidae acari are considered the most important and studied predatory mites. The objective of this study was to evaluate the effects of the webbing produced by O.ilicis on its predation by females of the phytoseiids Iphiseiodes zuluagai Denmark & Muma, Euseius citrifolius Denmark & Muma and Amblyseius herbicolus (Chant). Four bioassays were conducted, with three treatments and ten replicates. Each replicate consisted of 25 O.ilicis per experimental unit (a leaf disc of Coffea arabica) according to the tested developmental stage, in independent experiments. To spin the web, 15 adult females were put on each experimental unit for 24h; females were then removed, leaving only the web, and predators and prey to be tested were introduced. Predation was assessed after 24h. In the presence of webbing, the consumption of eggs, larvae and nymphs by I.zuluagai and eggs and larvae by E.citrifolius was lower. For A.herbicolus, egg predation was lower, but larval predation did not vary significantly and predation of nymphs and adults was higher in the presence of webbing. Predators as a whole were more efficient consuming larvae regardless of the presence of webbing. Considering the stages of O.ilicis altogether, webbing reduced the predation potential of I.zuluagai and E. citrifolius, but not of A. herbicolus.

Em um levantamento conduzido em espécies arbóreas da família Euphorbiaceae, incluindo plantas nativas e a seringueira, em três regiões do Estado de São Paulo, vinte e cinco espécies já descritas de ácaros da família Phytoseiidae foram encontradas. Vários dos ácaros coletados eram conhecidos até o momento apenas pela descrição original. Cinco das espécies relatadas neste trabalho correspondem a novas combinações. Descrições complementares de várias das espécies coletadas são apresentadas.

Twenty five known mite species of the family Phytoseiidae were found in a survey conducted on trees of the family Euphorbiaceae, including native plant species and rubber tree, in three regions of the State of São Paulo. Several of the species collected were known until now only from the original description. Five of the mite species mentioned in this paper correspond to new combinations. Complementary descriptions of several of the species collected are provided.

A simple and effective suction collector device for plant inhabiting mites directly into vials is described.