ABSTRACT
ABSTRACT Vatiga manihotae (Drake 1922) (Hemiptera: Tingidae) is an important cassava pest due to the great potential damage and the increasing population in recent years. However, few studies about bioecology and control of the cassava lace bug have been conducted and their results don't provide adequate control strategies. An alternative to maintain the population below economic injury levels is through the adoption of host plant resistance. To improve the understanding about the bioecology and find new sources of resistance in cassava, the biological parameters and demographics of V. manihotae on five cassava genotypes (Santa Helena, MEcu 72, Col 22, Clone 02 and Clone 03) under controlled conditions (25±2°C, 14L/10D) were evaluated. Duration and viability of the stages, the period egg-adult, sex ratio, the pre-oviposition period, fecundity and longevity of male and female was determined, and a fertility life table was prepared. Insects fed on MEcu 72 showed increased nymphal, egg-adult, and pre-oviposition periods and reduced female fecundity and longevity in comparison to the other genotypes. Demographic parameters (Ro, rm, T, DT) showed a significant impact on the growth potential of V. manihotae fed on MEcu 72 indicating that the populations would diminish over time. The combined effect of these parameters indicated that MEcu 72 has resistance on V. manihotae specimens hindering their development.
ABSTRACT
Este trabalho registra a ocorrência de Aleurothrixus aepim Goeldi em plantas de mandioca na região Oeste do Paraná, Brasil. A espécie foi primeiramente encontrada em fevereiro de 2009, em área experimental da Universidade Estadual do Oeste do Paraná (UNIOESTE), em folhas de mandioca da variedade fécula branca. Os exemplares foram coletados recolhendo-se folhas infestadas com ninfas de mosca-branca, caracterizadas por apresentar corpo recoberto por filamentos cerosos de coloração branca. O material foi preservado em etanol a 70%, em frascos de vidro, e foram enviados para identificação. Novos surtos foram registrados no início de 2010 e 2011 em diferentes propriedades rurais localizadas no município de Marechal Cândido Rondon. Entretanto, a causa precisa da ocorrência de A. aepim nessa região não está totalmente clara. Nas demais regiões produtoras do Estado, esta espécie ainda não foi detectada.(AU)
This paper work recorded the occurrence of Aleurothixus aepim Goeldi in cassava plants in the West of Parana, Brazil. The species was first found in February, 2009, in an experimental area at Universidade Estadual do Oeste do Paraná (UNIOESTE), in cassava leaves of the white starch variety. The samples were collected by gathering leaves infested with whitefly nymphs, which are characterized for presenting body coated by white waxy filaments. The material was preserved in 70% ethanol, in glass bottles, and sent for identification. New outbreaks have been recorded in the beginning of 2010 and 2011 in different rural properties located in the city of Marechal Candido Rondon. However, the precise cause of the occurence of A. aepim in this region is not completely clear. In the other production regions of the State, this species has not yet been detected.(AU)