Biology of Bemisia tuberculata Bondar (Aleyrodidae) and parasitism by Encarsia porteri (Mercet, 1928) (Hymenoptera, Aphelinidae) on cassava plants

Abstract

The whitefly Bemisia tuberculata has caused serious damage to cassava producing areas in the state of Mato Grosso do Sul. However, little is known about the biological characteristics of this species. The objective of this study was therefore, to monitor the development of this species bred on cassava plants under controlled greenhouse conditions, and to determine its most vulnerable stages and its reproductive capacity, as well as measuring the length and width each stage of development. To obtain these data, adult individuals were kept in voile traps on cassava leaves of five different plants, totalling ten leaves. After 24 hours the leaves were removed from the traps thus making each egg-laden leaf an experimental unit. The lowest mortality rate was record in the last nymphal stage ('pupae) compared with the other development stages. The highest mortality occurred in the nymphs at the 2 nd and 3 rd instars. Each female laid an average of 6.3 eggs in 24 hours. Thirteen days after egg laying, every one of the nymphs was fixed on the leaves of cassava plants. From the egg laying stage up until the adult stage, the process took 26 days. The proportion of females was 73.5%. The average size of the B. tuberculata egg was 163.22 µm in length and 72.39 µm in width and the "pupae" is 915.82 µm in length and 628.71 µm in width. The measurements of males were 797.16 µm in length and 200.81 µm in width and the length females 916.12 µm in length and 338.99 µm in width. The parasitoid Encarsia porteri (Mercet, 1928) (Hymenoptera, Aphelinidae) was found in the insect stock culture.Keywords: cassava pest, life table, Manihot esculenta. Biologia de Bemisia tuberculata (Hemiptera: Aleyrodidae) em mandioca ResumoA mosca-branca Bemisia tuberculata tem causado sérios danos a áreas produtoras de mandioca do Estado do Mato Grosso do Sul. No entanto, pouco se sabe sobre as características biológicas dessa espécie. O objetivo deste trabalho foi, portanto, acompanhar o desenvolvimento dessa espécie criada em plantas de mandioca em condições de casa de vegetação, além de determinar as suas fases mais vulneráveis e a sua capacidade reprodutiva, e medir o comprimento e a largura das fases de desenvolvimento. Para obter esses dados, os indivíduos adultos foram mantidos em armadilhas voil de folhas de mandioca, de cinco plantas diferentes (duas folhas por planta), totalizando dez folhas. Após 24 horas, as folhas foram retiradas das armadilhas, tornando-se cada folha carregada de ovos uma unidade experimental. Na última fase de ninfa (pupa), a menor taxa de mortalidade foi observada, em comparação com os outros estágios de desenvolvimento. A maior mortalidade ocorreu em ninfas, fixadas em segundo e terceiro ínstares. Cada fêmea depositou uma média de 6,3 ovos em 24 horas. Após 13 dias de postura dos ovos, todas as ninfas estavam fixas nas folhas das plantas de mandioca. A partir da postura dos ovos até a fase de aparecimento dos adultos, foram necessários 26 dias. Houve uma proporção de 73,5% de fêmeas. Os ovos de B. tuberculata med...

Occurrence and distribution of lace bug, whitefly, and shoot fly pest species on cassava (Manihot esculenta) crops according to region in Paraná State, Brazil

“…These crops could be a unique income source for resource-poor families. In general, cassava pests develop properly in environmental conditions that are suitable for the related plants, particularly under higher temperatures (Waddill, 1977;Gisloti & Prado, 2013;Bellon et al, 2017;Miranda et al, 2009;Andrade et al, 2012), which generally occur in the Paraná regions in spring and summer.…”

“…The biological life cycle of V. manihotae occurs over approximately 22 days (25 + 2 ℃) (Miranda, Rheinheimer, Bellon, Gazola, & Pietrowski, 2009). At 26 + 4 ℃ B. tuberculata survives for approximately 26 days (Andrade, Roel, Penteado-Dias, & Costa, 2012) and, for A. aepim, at similar temperatures, but reared on different cassava cultivars, the lifecycle varies from 26.8 to 30.5 days (Lima, Ringenberg, Fancelli, & Ledo, 2018).…”