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Studies on control of crab to a pest-insect and three kinds of weeds in rice-crab paddy-fields.
SHAO Yidong, YANG Yizhong, YU Yueshu,SHAO Hong ,LU Ziqiang
Chinese Agricultural Science Bulletin
2004, 20 (2):
178-178.
DOI:
10.11924/j.issn.1000-6850.0402178
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.
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