Performance of an oligophagous insect in relation to the age of the host plant

• Autor(a) principal: Campos,Wellington G.
• Data de Publicação: 2003
• Outros Autores: Schoereder,José H., Picanço,Marcelo C.
• Tipo de documento: Relatório
• Idioma: eng
• Título da fonte: Neotropical entomology (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2003000400019
• topic: Larval development; reproductive sucess; plant phenology; Plutella xylostella; Lepidoptera

The performance of monophagous and oligophagous herbivore insects should be negatively influenced by the ageing of their host plants. Plutella xylostella L. (Lepidoptera: Yponomeutidae), a specialist in Cruciferae, was reared in the laboratory on detached cabbage leaves (Brassica oleraceae var. capitata). We used fourth expanded leaves from differently aged plants, and leaves from three strata of the mature plant. Plant ageing increased pre-imaginal mortality and reduced larval developing rate, pupae weight, and fecundity. The insect net reproductive rate (Ro) and intrinsic rate of population growth (r) decreased as plant aged. No leaf category of mature plants was qualitatively superior to leaves from younger plants. If there exist a positive correlation between oviposition preference and offspring performance, in field conditions, a decreasing temporal trend in the intensity of attack along the host plant development can be expected.