Aspectos da biologia de Aphis gossypii Glover, 1877 (Hemiptera: Aphididae) em quatro cultivares dealgodoeiro, em laboratório

Abstract

It was aimed to study some biological aspects of Aphis gossypii Glover fed on cotton cultivars Allen, IPEACO-SL 21-61131, JPM 781-88-3 and Auburn SM 310 in experiments conducted at 25 ± 2ºC, 60 ± 10% of RH and 12-hour photophase in a completely randomized design. Adult females obtained after the last ecdysis were mantained on leaf disks of those cultivars for 24 hours and from the produced nymphs, one was chosen at random for the conduction of the experiment. The density and the sorts of trichomes on each cultivar were evaluated. The cultivar JPM 781-88-3 enabled the best development of the aphid with a daily production of 4.2 ± 0.1 nymphs/female and a total of 69.2 ± 2.1. On the cultivar IPEACO-SL 22-61131, a lenghtening of the nymphal stage and reduced fecundity took place with a daily mean of 3.0 ± 0.3 nymphs/female and a whole of 54.9 ± 2.2 nymphs/female. The cultivar Auburn SM 310 affected the biological cycle of this aphid, reducing its duration. As regards the sorts of trichome, star-shaped non-glandular and glandular structures were identified, with the predominance of the first type. The highest densities of non-glandular trichomes were found on the cultivars Allen and IPEACO-SL 21-61131 while the glandular ones occurred in a greater number on the cultivars JPM 781-88-3 and Allen. On Auburn SM 310 no sort of trichom was found.