Obtusicauda Soliman

This page updated: January 2026.

I really enjoy this genus, feeling like it is an old friend as I walk, camp, explore the sagebrush lands of the west.  It is easy to find from the sandy deserts of Utah to the high mountain slopes of Idaho.  This is another example of a group in which I think species-level taxonomy is so poorly understood that I have rarely place a species name on specimens in my collection. In December 2025 and January 2026 I tackled a major sort of my specimens and an evaluation of the literature of Obtusicauda in North America. See the essay here. Almost all the details I know about the genus are in that essay. Below are a couple photos and some enthusiasm.

Obtusicauda is unusual for the aphids I study in that the oviparae lay eggs in massive groups at the ends of young shoots. Then the fundatrices hatch together and form dense gatherings in the spring.  During the summer in the mountains Obtusicauda is a frequent migrant colonist — alate viviparae can be found on the edge of ‘spring’ all summer as the season crawls up the mountain slopes, the snow banks melt, etc.  It seems obvious that a lot of the Obtusicauda at high elevations are colonizing from lower elevations.  I cannot say whether it seems that such high elevation colonies then remigrate to the low lands in fall.