烟粉虱若虫在夏大豆植株上分布的研究

对烟粉虱若虫在223份不同结荚习性大豆品种植株上的分布进行了调查研究.结果表明烟粉虱若虫在夏大豆植株上的总体分布集中在中上部,占总数的83.1%,中部与上部之间差异不显著.不同结荚习性大豆品种上烟粉虱若虫的分布存在明显差异.有限结荚习性品种主要分布在上部,上4叶烟粉虱数占单株烟粉虱总数的57.7%;无限结荚习性品种主要分布在中上部,第11叶至第16叶上烟粉虱数占单株烟粉虱总数的53.1%;亚有限结荚习性品种中5叶烟粉虱数占单株烟粉虱总数的39.6%,上5叶烟粉虱数占单株烟粉虱总数的41.4%.由此可以看出,化学防治烟粉虱的重点部位是大豆植株的中上部叶片.

STUDIES ON THE DISTRIBUTION OF WHITEFLY NYMPH ON SUMMER SOYBEAN PLANTS

The distribution of whitefly nymph on the plants of 223 summer soybean varieties was in vestigaled. The result showed that 83.1M of whitefly nymphs were present on top and middle leaves and there was no marked difference between middle and top leavesl significant difference was observed on the distribution of whitefly nymphs among different podding habit soybean varieties. In determinate podding habit varieties, 57.7% of whitefly nymphs were present on upper 4 leaves; in indeterminate podding habit varieties, 53.1% of whitefly nymphs were present on from the 11th leaves to 16th leaves; in semi-determinate podding habit varieties, 39.6% and 41.4%of whitefly nymphs were present on the 5 middle leaves and 5 top leaves, respectively. The chemical control of whitefly nymphs should mainly focus on the top and middie leaves according to the whitefly nymph distribution.