Schultz J C, Lechowicz M J
Department of Entomology, Pesticide Research Laboratory, The Pennsylvania State University, 16802, University Park, PA, USA.
Department of Biology, McGill University, 1205 Avenue Docteur Penfield, H3A 1B1, Montreal, Quebec, Canada.
Oecologia. 1986 Dec;71(1):133-137. doi: 10.1007/BF00377332.
The midgut pH of late instar gypsy moth (Lymantria dispar L.) larvae is strongly alkaline, and varies with diet, larval stadium, and time since feeding. Midgut pH rises with time since feeding, and does so more quickly, reaching greater maximum values, on some diets than others. Leaf tissues of 23 tree species resist increases in alkalinity differentially; this trait and differing initial leaf pH may explain the impact of diet on gut pH. Third instar larvae may have gut conditions favorable for tannin-protein binding shortly after ingesting certain foods, but with time midgut alkalinity becomes great enough to dissociate tannin-protein complexes. Older instars rarely exhibit gut pHs low enough to permit tannin activity. Alkaline gut conditions may explain the gypsy moth's ability to feed on many tanniniferous plant species, especially in later instars. Consequences for pathogen effectiveness are discussed.
舞毒蛾（Lymantria dispar L.）末龄幼虫的中肠pH值呈强碱性，且会因食物种类、幼虫龄期以及进食后的时间而变化。中肠pH值会随着进食后的时间而升高，在某些食物上，其升高速度更快，达到的最大值也更高。23种树木的叶片组织对碱度增加的抵抗能力存在差异；这一特性以及不同的初始叶片pH值可能解释了食物对肠道pH值的影响。三龄幼虫在摄入某些食物后不久，其肠道环境可能有利于单宁 - 蛋白质结合，但随着时间推移，中肠碱度会变得足够高，从而使单宁 - 蛋白质复合物解离。老龄幼虫很少表现出足以使单宁发挥活性的低肠道pH值。碱性肠道环境可能解释了舞毒蛾以许多富含单宁的植物为食的能力，尤其是在老龄期。文中还讨论了对病原体效力的影响。
