Insect Overwintering Stages in an Alpine Meadow in Relation to Their Phylogeny and Soil Depth

Abstract

Temperate-climate insects vary in overwintering life stages even within local communities, but factors driving this variation are not well understood. We studied the density and overwintering stages of insects in an alpine meadow on the eastern Tibetan Plateau, and generated a phylogenetic tree of the insects based on DNA barcoding. The total number of studied individuals (of all four stages) was 2211; they belonged to 88 species, 36 families and 6 orders. Insect overwintering stages were phylogenetically conserved across species, primarily because particular stages dominated in related orders or families. In addition, immobile egg and pupal stages were common in the topsoil layer, whereas larvae and adults occurred generally in the top and deep soil layers; and larvae were often larger in the lower than in the upper soil layers. Thus, the stages of overwintering insects are evolutionally conserved despite their associations with physical parameters (e.g., soil temperature) or species traits (e.g., body size).