Setälä H, Mäkelä I
Department of Biology, University of Jyväskylä, SF-40100, Jyväskylä, Finland.
Konnevesi Research Station, SF-44300, Konnevesi, Finland.
Oecologia. 1991 Apr;86(2):170-176. doi: 10.1007/BF00317528.
The grazing effects of the waterlily beetle Galerucella nymphaeae on Nuphar lutea stands were studied in three ponds in Central Finland. Production of floating leaves of N. lutea and growth in the G. nymphaeae population were investigated in the ponds and bioenergetics of the beetle larvae in the laboratory. Combination of field and laboratory data enabled estimation of the effect of the beetle on the production of floating leaves of N. lutea and the consequences of grazing for the input of detritus from Nuphar into the ponds. Adults and larvae of G. nymphaeae consumed 3.0-6.1% of the net annual floating leaf production during the growing period. In addition to consumption losses, feeding accelerated the degradation rate of the leaves. This was associated with an increased flow of detrital material of Nuphar origin, and also with increased production of floating leaves in the ponds. These increments were estimated to be up to 3 times greater in the presence of grazing than without it. Grazing by G. nymphaeae releases substantial amounts of carbon and nitrogen bound in Nuphar, particularly in ponds with a dense Nuphar vegetation. It is hypothesized that feeding by this beetle may markedly affect the structure and functioning of such small aquatic systems.
在芬兰中部的三个池塘中，研究了睡莲叶甲对黄花睡莲群落的啃食影响。在池塘中调查了黄花睡莲浮叶的产量以及睡莲叶甲种群的增长情况，并在实验室研究了叶甲幼虫的生物能量学。结合田间和实验室数据，可以估算叶甲对黄花睡莲浮叶产量的影响，以及啃食对黄花睡莲碎屑输入池塘的影响。在生长季节，睡莲叶甲的成虫和幼虫消耗了每年浮叶净产量的3.0%-6.1%。除了消耗损失外，取食还加速了叶片的降解速度。这与黄花睡莲来源的碎屑物质流量增加有关，也与池塘中浮叶产量的增加有关。据估计，有啃食情况下的这些增量比没有啃食时大3倍。睡莲叶甲的啃食释放了大量结合在黄花睡莲中的碳和氮，特别是在黄花睡莲植被密集的池塘中。据推测，这种叶甲的取食可能会显著影响此类小型水生系统的结构和功能。
