模拟及实地条纹黄瓜甲虫脱叶作用对‘Carolina’黄瓜光合反应的影响(英文)

１９９５年作者进行了田间试验来比较模拟的条纹黄瓜甲虫 Ａｃａｌｙｍｍａ　Ｖｉｔｔａｔｕｍ（Ｆ）脱叶作用及实地Ａ．ｖｉｔｔａｔｕｍ脱叶作用对‘Ｃａｒｏｌｉｎａ’黄瓜光合反应的影响。在５个生长阶段（从第一片真叶到收获）中，共模拟了６种脱叶水平（０％一１００％）。在每一生长阶段，每点植株每周两次用剪子去叶，这一处理叫连续脱叶。除此之外，对同一生长阶段植株也用了一次性脱叶处理，但只有４种脱叶水平（０，２５，５０及１００％）。用Ａ．ｖｉｔｔａｔｕｍ成虫笼养试验来估计实地害虫脱叶危害。每笼中甲虫放置时间为两周，密度各为每株０，１，３，５及１０头，测定其净光合速率。在模拟及实地害虫脱叶处理之间，没有测到显著的光合速率差异（ Ｐ＞０． ０５）。在模拟害虫脱叶试验中，受损叶片和未受损叶片的光合速率也很少有显著差异。结果显示模拟害虫脱叶处理过程不仅能准确反映实地Ａ．ｖｉｔｔａｔｕｍ脱叶危害下的‘Ｃａｒｏｌｉｎａ’黄瓜的生长反应，而且也适用于确定Ａ．ｖｉｔｔａｔｕｍ对黄瓜的经济危害水平。

PHOTOSYNTHESIS RESPONSE OF 'CAROLINA'CU-UCUMBER TO SIMULATED AND ACTUAL STRIPED CU-CUMBER BEETLE (COLEOPTERA:CHRYSOMELI-DAE)DEFOLIATION

Field studies were conducted in 1995 to compare the photosynthesis response between simu- lated striped cucumber beetle, Acalymma vittatum (F. ), defoliation and actual A. vittatum defoliation in 'Carolina' cucumber. Six simulated defoliation levels (0%-100% )were used over 5 timings of defoliation (first true leaf to harvest). Plots were defoliated with scissors twice each week throughout each timing in-terval, and defined as continuous defoliation. In addition to continuous defoliation, one-time simulated de-foliation treatments were imposed using the same timing treatments but only 4 defoliation levels (0, 25, 50, and 100% ). Two cage studies, with A. vittatum adults, were used to provide estimates of actual in- sect defoliation injury. Beetles were placed in cages for 2 weeks at densities of 0, 1, 3, 5, and 10/plant and net photosynthetic rates were measured. No significant differences (P >0. 05) were detected in photosynthetic rates between simulated and actual insect defoliation treatments. Also, few significant differ- ences in photosynthetic rates were detected between damaged and undamaged leaves in the simulated insect defoliation study. Results indicated that the simulated insect defoliation procedure appeared to accurately reflect the growth response of 'Carolina' cucumber subjected to actual A. vittatum defoliation, and that simulated defoliation results should be appropriate for developing economic injury levels for A. vittatum on cucumber.