Vertical Distribution of Eggs and Larvae of the Bollworm Within the Cotton Plant.

• Autor(a) principal: BRAGA SOBRINHO, R.
• Data de Publicação: 1991
• Outros Autores: YOUNG, J. H., YOUNG, L. J.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/106190
• topic: artificial infestation; fenology; Gossypium Hirsutum; Heliothis Zea

The cotton cultivar ´Tamcot CAMD-E´, Gossypium hirsutum L., was planted in three different planting dates. Five wood-framed screen cages were used to cover 30 cotton plants during match-head squares and blooming phase for each planting date. Five female and five male bollworm moths, Heliothis zea, were released in each cage. The majority of eggs were laid on the upper part of the plant. The greatest proportions of eggs were observed during the second infestation period, which coincided with the blooming phase. Leaves were the most common place for eggs deposition. Terminal alone is probably not a good place to scount for larvae. The greatest proportion of larvae were found on the upper part of the plant during the second infestation period, which coincided with a larger canopy and more fruiting structures available. High correlations were obtainded among eggs on leaves and total number of eggs on the whole plant. Total larvae on the upper part of the plant yielded higher correlation coefficients than larvae on the terminal. This was true in all infestations and planting dates.