Insect Attractants, Behavior, and Basic Biology Research Laboratory Agricultural Research Service, U.S. Department of Agriculture, P.O. Box 14565, 32604, Gainesville, Florida.
J Chem Ecol. 1993 Mar;19(3):411-25. doi: 10.1007/BF00994314.
Regurgitate of corn-fed beet armyworm (BAW) caterpillars,Spodoptera exigua, when applied to damaged sites of corn (Zea mays) seedlings, causes the release of relatively large amounts of terpenes by the seedlings several hours later. This plant response could be induced by merely placing the cut stem of seedlings in a solution of BAW regurgitate for 12 hr, a response that could not be induced by placing seedlings in water only. Regurgitate of BAW fed various diets, including a minimal diet of filter paper, were all active. However, seedlings placed in corn leaf juice, BAW hemolymph, or BAW feces extract released significantly smaller amounts of terpenes than did seedlings placed in BAW regurgitate. These results indicate that the active components are present in relatively large concentrations in regurgitate and that they are not related to the food source. Furthermore, regurgitate from several other species of caterpillars (Spodoptera frugiperda, Helicoverpa zea,Trichoplusia ni, andAnticarsia gemmatalis) as well as from the grasshopperSchistocerca americana induced the release of significant amounts of terpenes in corn seedlings. The release of these volatiles, therefore, appears to be a general response to attack by phytophagous insects. The terpene-releasing corn seedlings were highly attractive to the generalist parasitoidCotesia marginiventris and to the specialized parasitoidMicroplitis croceipes. This study confirms a systemic herbivore-elicited release of terpenes in corn. It is proposed that such chemicals serve multifunctional purposes that directly and indirectly protect plants against herbivorous arthropods and pathogens.
被喂食玉米的甜菜夜蛾（BAW）幼虫反刍的物质，当被应用于受损的玉米（Zea mays）幼苗部位时，会导致幼苗在数小时后释放出相对大量的萜烯。这种植物反应仅通过将幼苗的切口茎放置在 BAW 反刍物的溶液中 12 小时就可以诱导，而将幼苗仅放置在水中则不能诱导这种反应。BAW 喂食的各种饮食，包括滤纸的最低饮食，都是有效的。然而，与放置在 BAW 反刍物中的幼苗相比，放置在玉米叶汁、BAW 血淋巴或 BAW 粪便提取物中的幼苗释放的萜烯量明显较小。这些结果表明，活性成分在反刍物中以相对较高的浓度存在，并且与食物来源无关。此外，来自几种其他毛虫物种（Spodoptera frugiperda、Helicoverpa zea、Trichoplusia ni 和 Anticarsia gemmatalis）以及草蜢 Schistocerca americana 的反刍物也会诱导玉米幼苗释放大量萜烯。因此，这些挥发性物质的释放似乎是对植食性昆虫攻击的一般反应。这些释放挥发性物质的玉米幼苗对广食性寄生蜂 Cotesia marginiventris 和专食性寄生蜂 Microplitis croceipes 具有高度吸引力。本研究证实了玉米中存在系统性草食性昆虫诱导的萜烯释放。据推测，这些化学物质具有多种功能，可直接和间接保护植物免受植食性节肢动物和病原体的侵害。
