Efeito de Extratos Etanólicos de Folhas e Ramos de Quatro Espécies do Gênero CrotonABSTRACT -The two-spotted spider mite Tetranychus urticae is one of the principal agricultural pests, infesting important crops such as cotton, grapes and tomatoes. In recent years, studies with the objective of using plant extracts as an alternative pest control are being intensified, showing to be a promising alternative and attracting the interest of a growing number of scientists. The present study aimed to evaluate the residual effect of 1% ethanol extracts of leaves and branches of four species of the genus Croton (C. rhamnifolius Kunth, C. sellowii Baill, C. jacobinensis Baillon, C. micans (Baill)) on the spider mite T. urticae. Leaf disks with the mites were immersed for five seconds in the extracts. It could be verified that the leaf extract of C. sellowii caused 69% mortality and the leaf extract of C. jacobinensis was not toxic to the spider mite. From the experiments it was concluded that the fecundity of the mites was affected and that the extracts were repellent at a concentration of 1%.KEY-WORDS: two-spotted spider mite, botanical acaricide, repellence; Croton spp.The uncontrolled use of insecticides in plantations has caused serious damage to the environment (Roel 2001). Therefore, many works are being done to find natural compounds with insecticidal properties (Oliveira et al. 1999, Pontes et al. 2007a, 2007b. In this context the study of the toxic effects of plant extracts on phytophagous mites is interesting , Jones et al. 1996. The two-spotted spider mite Tetranychus urticae Koch is considered one of the most important agricultural pests, infesting crops including cotton, tomatoes and grapes (Moraes & Flechtmann 2008).As an alternative for synthetic insecticides, plant extracts were heavily investigated in recent years as a source of bioactive substances (Barakat et al. 1986a(Barakat et al. , 1986b, Potenza et . 1999a. , 1999b. , Pontes et al. 2007c. Among native species with recognised insecticidal potential, those of the genus Croton are outstanding. Species of this genus are common in various biomes of the state of Pernambuco, Brazil. Species of Croton are popularly known as "marmeleiro" or "velame" and many are used as drugs for the treatment of hypertension, ulcers and as anti-inflammatories (Maciel et al. 2000, Abdel Gadir et al. 2003, Nardi et al. 2003, Suárez et al. 2003, Guerrero et al. 2004, Lopes e Lopes et al. 2004).The search for insecticidal properties in medicinal plants is growing in the last few years and shows to be a promising alternative (Alexander et al. 1991, Roel 2001, Park et al. 2002. Croton cajucara Benth and C. linearis Jacquin have shown medicinal properties (Maciel et al. 2000, Almeida et al. 2003, Guerrero et al. 2004 and from these species secondary compounds with insecticidal properties were isolated (Kubo et al. 1991, Alexander et al. 1991. According to literature, no works on the acaricidal activity of the species C. jacobinensis, C. sellowii, C. rhamnifolius and C. micans ha...
