Calaphis

Calaphis is a genus of aphids belonging to the family Aphididae. These aphids are typically found feeding on the leaves and stems of various deciduous trees, particularly those in the Betulaceae (birch family) and Alnus (alder) genera. They are characterized by their small size, generally pale coloration (often greenish or yellowish), and the presence of distinctive cornicles (siphunculi), which are short, truncate tubes projecting from the posterior of the abdomen used for defense.

Calaphis aphids are generally host-specific, meaning that each species tends to feed on a limited number of host plants. The life cycle of Calaphis aphids can be complex, involving both sexual and asexual reproduction, and may also include host alternation in some species. Populations can fluctuate significantly depending on environmental conditions and the presence of natural enemies such as ladybugs, lacewings, and parasitic wasps. Outbreaks of Calaphis aphids can, in some cases, cause aesthetic damage to host trees, although they rarely cause significant long-term harm. The identification of Calaphis species often requires microscopic examination and analysis of morphological characteristics.