中华绒螯蟹取食褐飞虱与3种杂草的初步研究

Studies on Control of Crab to a Pest-insect and three Kinds of Weeds in Rice-Crab Paddy-Fields

在室内研究了中华绒螯蟹对 1种水稻害虫褐飞虱和 3种稻田杂草紫背萍、稗草、水莎草的取食作用。结果表明 ,中华绒螯蟹对褐飞虱的控制作用相当明显 ,且随着褐飞虱密度的增加 ,河蟹对它的取食量明显增加 ;河蟹对 3种稻田杂草的取食则存在明显的选择性 ,总的表现为对紫背萍和水莎草的取食能力强 ,对稗草的取食能力弱 。

Feeding behavior of crab to a pest-insect (Nilaparvata lugens) and three kinds of weeds (Spirodela polyrrhiza, Echinochloa crusgalli, Juneceus serotinlls) in rice-crab paddy-fields were studied. The results showed that crab had different food-take to the weeds at its early stage, the order was S. polyrrhiza>J. serotinlls>E. crusgalli during the crab's period of growth. But with the development of crab,it was getting smaller and smaller, even no food-take;In designed N. lugens population density (5～40 heads), the functional response was belong to Holling-I. Three linear regression equations of experiment were as follows:Na=0.4167N-1.75, Na=0.4486N-2.0929 and Na=0.4505N-2.1857,the correlation coefficients all reached 0.99.