Geometrid moths of the genus Eupithecia Curtis, 1825 (Lepidoptera, Geometridae): Prerequisites and characteristic features of high species diversity

The prerequisites and characteristics of high species diversity of the genus Eupithecia (Geometridae), the largest in the order Lepidoptera, are discussed. The surge of speciation in this genus was facilitated by the evolutionarily advanced morpho-functional characters of the adults and larvae, as well as by the plasticity of a number of morphological structures, especially those of the genitalia in both sexes, in the ancestral Eupithecia. The wide range of flowering plants has served as a basis for close associations of the larvae predominantly with generative plant organs and for broad adaptive radiation of Eupithecia into a variety of ecological niches in the areas lacking their competitors from other genera of the tribe Eupitheciini. Transition of the larvae of some Eupithecia to facultative or obligate ambush predation was facilitated by adaptation of the antho- and carpophagous species to high-calorie food rich in proteins, lipids, and carbohydrates. Based on the distribution of the genus Eupithecia and its most morphologically primitive species-groups, its East Asian origin is hypothesized. It is noted that many of the largest genera of animals and plants include relatively small-sized species.