Karban R, Hougen-Eitzmann D, English-Loeb G
Department of Entomology, University of California, 95616, Davis, CA, USA.
Oecologia. 1994 May;97(4):508-511. doi: 10.1007/BF00325889.
We have been releasing economically unimportant herbivorous mites of one species early in the season and protecting grapevines against another, more damaging herbivorous mite throughout the growing season. In this experiment, releases of economically unimportant Willamette mites alone, or of predatory mites alone, failed to reduce populations of the damaging Pacific spider mite. However, where both herbivorous Willamette mites and predatory mites were released together populations of Pacific mites were reduced. This interaction between effects of Willamette mites and predatory mites suggests that predation against Pacific mites was more effective where alternate prey (Willamette mites) were available for the predators. The "apparent competition" between Willamette mites and Pacific mites, mediated through their shared predator, can be an important force in the agroecosystem although its importance varies from year to year and vineyard to vineyard.
我们在季节早期释放一种经济上不重要的植食性螨类，并在整个生长季节保护葡萄藤免受另一种更具危害性的植食性螨类侵害。在本实验中，单独释放经济上不重要的威拉米特螨或单独释放捕食螨，均未能减少具有危害性的太平洋叶螨的种群数量。然而，在同时释放植食性威拉米特螨和捕食螨的地方，太平洋叶螨的种群数量减少了。威拉米特螨和捕食螨的这种相互作用表明，在有替代猎物（威拉米特螨）可供捕食者食用的情况下，对太平洋叶螨的捕食更为有效。威拉米特螨和太平洋叶螨之间通过它们共同的捕食者介导的“表观竞争”，可能是农业生态系统中的一种重要力量，尽管其重要性因年份和葡萄园而异。
