Biological parameters of Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae) on Jatropha gossypiifolia, commercial (Manihot esculenta) and wild cassava (Manihot flabellifolia and M. carthaginensis) (Euphorbiaceae)

Bemisia tabaci (Gennadius) is one of the most important pests of cassava in Africa and several countries of Asia due to the damage caused by direct feeding, the excretion of honeydew, and its capacity as a vector of cassava mosaic geminivirus. There is a general consensus that B. tabaci is a complex of morphologically indistinguishable populations with different biotypes. In the Americas, the polyphagous biotype B does not appear to feed on cassava. Recent studies indicate that it is possible, however, for biotype B to gradually adapt to cassava using phylogenetically related hosts. Therefore, the possibility that some wild species of cassava constitute intermediate hosts in the adaptation process may lead to the establishment of biotype B on commercial varieties of Manihot esculenta. In here, we evaluated Jatropha gossypiifolia, two wild species of cassava (Manihot flabellifolia and M. carthaginensis) and a commercial cassava variety (MCol 2063) as hosts of biotype B. The highest oviposition rate (2.7 eggs /two days) occurred on M. esculenta, although the development time (44 d) was the longest when compared to M. carthaginensis and J. gossypiifolia. About 60 percent of the population could reproduce on the wild cassava species vs. 55 percent on J. gossypiifolia and 27.5 percent on the commercial variety. Our data suggest that J. gossypiifolia is a suitable host and the wild species M. carthaginensis can constitute a potential intermediate host in the adaptation of biotype B to commercial varieties of cassava.

Diversidade de moscas-das-frutas, suas plantas hospedeiras e seus parasitóides nas regiões Norte e Noroeste do Estado do Rio de Janeiro, Brasil / Fruit fly diversity, their host plants and their parasitoids in the northern and northwestern regions of Rio de Janeiro State, Brazil

Em razão da exploração crescente da fruticultura nas regiões Norte e Noroeste do Estado do Rio de Janeiro e da importância econômica e quarentenária das moscas-das-frutas para essa atividade agrícola no mundo, este estudo foi conduzido em cinco municípios dessas regiões: Cambuci, Campos dos Goytacazes, Itaocara, São Francisco do Itabapoana e São João da Barra, com objetivo de registrar as espécies de moscas-das-frutas, suas plantas hospedeiras e seus parasitóides. Os espécimes foram coletados por meio de armadilhas McPhail com solução aquosa de proteína hidrolisada a 5 por cento e em amostras de frutos. Nas armadilhas, 4 por cento do total de moscas-das-frutas capturadas foram Ceratitis capitata e 96 por cento eram do gênero Anastrepha, num total de 15 espécies. Das moscas capturadas nas armadilhas, apenas seis espécies infestaram frutos entre as 12 espécies de fruteiras amostradas. Fruteiras das famílias Anacardiaceae, Malpighiaceae, Myrtaceae, Oxalidaceae, Passifloraceae e Sapotaceae foram plantas hospedeiras de moscas-das-frutas. Apenas três espécies de Anastrepha (A. fraterculus, A. sororcula e A. zenildae) infestaram goiabas da variedade comercial Paluma. Os parasitóides de larvas de moscas-das-frutas encontrados foram Doryctobracon areolatus e Aganaspis pelleranoi, parasitando-as em frutos de goiabeira e de outras fruteiras nessas regiões.

Due to the increase in fruit crops acreage in the northern and northwestern regions of Rio de Janeiro State and to the economic and quarantine importance of the fruit flies to this agricultural activity in the world, this study was carried out in five municipalities of these regions: Cambuci, Campos dos Goytacazes, Itaocara, São Francisco do Itabapoana, and São João da Barra, aiming to study the fruit fly species, their host plants and their parasitoids. The specimens were collected using McPhail traps with aqueous solution of hydrolyzed protein to 5 percent and in fruit samples. In the traps, 4 percent of the total of fruit flies captured were Ceratitis capitata and 96 percent were from the genus Anastrepha in a total of 15 species. From these flies captured in the traps, only six species infested fruits among the 12 species of fruits sampled. Fruit trees of the families Anacardiaceae, Malpighiaceae, Myrtaceae, Oxalidaceae, Passifloraceae and Sapotaceae were host plants of fruit flies. Only three species of Anastrepha (A. fraterculus, A. sororcula and A. zenildae) infested guavas of the commercial variety Paluma. The parasitoids of fruit fly larvae found were Doryctobracon areolatus and Aganaspis pelleranoi, parasitizing them in fruits of guava and other fruit trees in these regions.