Rafes P F, Raspopov P M
Biol Bull Acad Sci USSR. 1979 Jan-Feb;6(1):47-54.
The aestivo-autumnal group of birch pests includes 25 species belong to the Notodontidae, Geometridae, Noctuidae, and other families. The larvae of all its species hatch out in mid-July and feed until the end of August. On emerging from the eggs they spread from leaf to leaf, but as the food supply diminishes they crowd together and competition is intensified. The species structure of the group shows some variation over the territory, and only a few species dominate, different species in different places. It is suggested that improvement in the food supply leads to mass reproduction. Biochemical investigations confirmed this hypothesis: different species feeding on the same leaf assimilate different amino acids more completely, and their relative numbers on the leaves vary in different parts and at different times. The composition of secondary metabolites important for resistance of the plants also varies.
桦树害虫的夏秋类群包括25种，分属于舟蛾科、尺蛾科、夜蛾科及其他科。其所有种类的幼虫于7月中旬孵化，一直取食到8月底。幼虫从卵中孵出后在叶片间扩散，但随着食物供应减少，它们会聚集在一起，竞争加剧。该类群的物种结构在不同区域存在一定差异，只有少数物种占主导地位，不同地方的优势物种不同。有人认为食物供应的改善会导致大量繁殖。生化研究证实了这一假设：取食同一片叶子的不同物种对不同氨基酸的同化更完全，且它们在叶片上的相对数量在不同部位和不同时间有所不同。对植物抗性很重要的次生代谢物的组成也有所变化。
