A study of the larvicidal activity of two Croton species from northeastern Brazil against Aedes aegypti.

The essential oils of Croton heliotropiifolius Kunth (Euphorbiaceae) and Croton pulegiodorus Baill. were selected for larvicidal evaluation against Aedes aegypti L. (Diptera: Culicidae) and studied qualitatively and quantitatively by GC and GC-MS. Sixty-one compounds representing 92.03% (C. heliotropiifolius) and 85.68% (C. pulegiodorus) of the essential oils, respectively, have been identified. The major components of C. heliotropiifolius essential oil were identified as beta-caryophyllene (35.82%), bicyclogermacrene (19.98%), and germacrene-D (11.85%). The major components in C. pulegiodorus essential oil were identified as beta-caryophyllene (20.96%), bicyclogermacrene (16.89%), germacrene-D (10.55%), tau-cadinol (4.56%), and beta-copaen-4-alpha-ol (4.35%). The essential oil of C. pulegiodorus (LC50 159 ppm) was more effective against Ae. aegypti than that of C. heliotropiifolius (LC50 544 ppm). In order to verify whether the major compound of both essential oils is the active principle responsible for the larvicidal activity, beta-caryophyllene was purchased and its larvicidal potential was further evaluated. However, beta-caryophyllene (LC50 1038 ppm) showed weak larvicidal potency. Results of larvicidal evaluation suggest the existence of a synergistic effect of minor components in the essential oils.

Estudios morfométricos y biológicos de xifidiocercarias provenientes de la infección natural de lymnaea columella y biomphalarias tenagophila recolectados en Miracatu estado Sao Paulo Brasil / Morphometric and biological studies on xiphidiocecariae recovered from lymnaea columella and biomphalaria tenagophila from Miracatu Sao Paulo state Brazil

Two species of xiphidiocercariae probably to the family Haematoloechidae (Trematoda) emerging from Lymnaea columella (Blasommatophora Lymnaeidae) and Biomphalaria tenagophila (Basommatophora, Planorbidae) collected in Miracatu City, Sao Paulo, Brazil, Septembrer 1996 and February 1999 were described. The xiphidiocercariae eliminated by L. columella presented a terminal membrane in the tail that morphologicaly differenciated them from those obtained from B. tenagophila. These late xiphidiocercariae were 1.3 times bigger than the former and with the of that ventral sucker bigger than the oral one, while the former presented a sucker size relation inverse. The stylet observed in the xiphidiocercariae eliminated by B. tenagophila oral sucker was shorter than that observed in xiphidiocercariae obtained from L. columella

Búsqueda de xifidiocercarias trematoda en moluscos de agua dulce recolectados en nueve municipios del Estado de Sao Paulo Brasil / Search of natural occurrence of xiphidiocercariae trematoda in fresh water snails of 9 counties from Sao Paulo State Brazil

Xiphidiocercariae, aquatic larval stages of some trematodes are considered a potential instrument for biological control of mosquitoes. In this study we evaluated its natural occurrence in Campinas region and two places in Vale do Ribeira (Registro and Miracatu), Sao Paulo State. Snails were obtained from fresh water collections from september 1996 to february 1999. The species collected were Lymnaea columella, Physa marmorata, Biomphalaria tenagophila, Biomphalaria sp., Drepanotrema cimex, D. lucidum and Drepanotrema sp. Fasciola hepatica, xiphidiocercariae (Haematoloeschidae) and echinostomatid cercariae were detected in the lymnaeids snails from Miracatu, SP. In the same locality were found planorbids snails parasitized by furcocercariae, echinostomatid cercariae and xiphidiocercariae. The xiphidiocercariae found in the planorbids were different from those obtained from lymnaeids. One Biomphalaria sp. infected with furcocercariae was found in Louveira, SP. In the ROSA place (Campinas, SP) an individual of Biomphalaria sp. and one of L. columella were found infected by the furcocercariae and echinostomatid cercariae, respectively. In the place UNI-I, in Campinas, one L. columella was infected by furcocercariae. Double infection in snails from Miracatu was also observed

Envio de girardia(=dugesia)tigrina (turbellaria, tricladida) para uso como agentes de controle de mosquitos em programas educativos / Chipment of girardia(=dugesia)tigrina (turbellaria, tricladida) to use as mosquito control agent in educational programs

Desde o começo do século, vários estudos têm demonstrado o alto potencial de predaçäo de planárias contra larvas de mosquitos. O potencial de uma linhagem de GIRARDIA TIGRINA no controle de larvas de AEDES ALBOPICTUS e CULEX QUINQUEFASCIATUS tem sido estudado na Unicamp sob condiçöes de campo e laboratório. Com o propósito de utilizar planárias em programas educativos sobre a dengue e a importância do controle dos mosquitos vetores, foi avaliado o armazenamento e envio de lotes de G. TIGRINA a longas distâncias, pelo correio. As planárias foram acondicionadas aos pares em pequenos frascos e despachadas em caixa de papeläo via SEDEX (aéreo) ou correio de superfície entre Campinas-SP e Säo Leopoldo-RS, ida e volta (2.600Km). Nos dois destinatários a sobrevivência e a quantidade de planárias bipartidas ou regenerantes.