Scriber J Mark
Dept. of Entomology, University of Wisconsin, 53706, Madison, Wisconsin, USA.
Oecologia. 1981 Jan;51(2):175-180. doi: 10.1007/BF00540597.
This study illustrates the diversity of feeding responses of individually polyphagous southern armyworms, Spodoptera eridania, to plants with differing allelochemics. In spite of the near optimal leaf water and nitrogen contents of the young foliage, it is apparent that vastly different larval growth performance results from dill, lima bean, and cabbage. Cabbage is the poorest food (as measured by larval growth rates and metabolic costs of processing the plant biomass). Unlike the case with certain other plant species or cultivars that are costly to process, with cabbage, S. eridania does not compensate for low efficiencies (E.C.D.'s) with increased consumption rates (R.C.R.'s). Biochemical or physiological reasons for this inability are unknown.A sequence of foods (changed each 18-24 h) apparently did not add sufficient stress upon the MFO system to be detected in the respiratory expenditures of S. eridania larvae, in spite of the fact that dill is known to contain insecticidal and synergistic chemicals (Lichtenstein et al. 1974). The larval growth performances and metabolic expenditures in these sequences were intermediate between the best food (dill) and the worse (cabbage). Significant differences were observed however between the sequential switching sequences, perhaps indicating that particular periods during the instar are especially more sensitive to certain allelochemics. Actual respiratory costs of the lima bean-cabbage-dill (i.e. B-C-D) sequence were 40-50% higher than observed for the other two sequences and more than 50% higher than the theoretical metabolic costs based on the proportions actually eaten and known costs associated with each food.This study and a related one (Scriber 1981a) illustrate how consumption rates, feeding efficiences, and larval growth of Spodoptera eridania are not species, population, or even individual characteristics, (cf. Fox and Morrow 1981), but instead depend largely upon variations in plant allelochemics and plant nutritional quality (Wolfson 1978; Scriber, 1981 b; Scriber and Slansky 1981). More significantly they illustrate that the food consumed in earlier instars (Scriber 1981 a) as well as the food consumed earlier in an instar can be a major influence upon the observed armyworm growth performances under a given set of environmental conditions.
本研究阐明了多食性的南方黏虫（草地贪夜蛾）对含有不同化感物质的植物的取食反应具有多样性。尽管幼嫩叶片的叶水含量和氮含量接近最佳水平，但显然，莳萝、利马豆和卷心菜导致幼虫生长表现差异极大。卷心菜是最差的食物（以幼虫生长速率和处理植物生物质的代谢成本衡量）。与某些其他加工成本高昂的植物物种或品种不同，南方黏虫对卷心菜并不会通过提高取食率来弥补低效率（E.C.D.）。造成这种无能的生化或生理原因尚不清楚。尽管已知莳萝含有杀虫和增效化学物质（利希滕斯坦等人，1974年），但一系列食物（每18 - 24小时更换一次）显然并未给南方黏虫幼虫的多功能氧化酶系统带来足够大的压力，以至于在其呼吸消耗中被检测到。这些序列中的幼虫生长表现和代谢消耗介于最佳食物（莳萝）和最差食物（卷心菜）之间。然而，在连续切换序列之间观察到了显著差异，这可能表明在龄期的特定阶段对某些化感物质特别敏感。利马豆 - 卷心菜 - 莳萝（即B - C - D）序列的实际呼吸成本比其他两个序列高出40 - 50%，比基于实际食用比例和与每种食物相关的已知成本计算出的理论代谢成本高出50%以上。本研究以及一项相关研究（斯克里伯，1981a）阐明了南方黏虫的取食率、取食效率和幼虫生长并非物种、种群甚至个体特征（参见福克斯和莫罗，1981年），而是在很大程度上取决于植物化感物质和植物营养质量的变化（沃尔夫森，1978年；斯克里伯，1981b；斯克里伯和斯兰斯基，1981年）。更重要的是，它们表明早期龄期消耗的食物（斯克里伯，1981a）以及龄期内较早消耗的食物在给定的一组环境条件下可能对观察到的黏虫生长表现产生重大影响。
