Woolly Root Aphid on Carrots in Dry Conditions

Root aphids (Pemphigus phenax) infest carrot roots, forming white, woolly masses in dry conditions. Visible as fluffy deposits and pale yellow aphids on roots, they are not structural pests but common in dry summers. Closely related to Pemphigus bursarius on lettuce, they overwinter on poplars, with winged forms dispersing to carrots in mid-June. Apterous offspring develop underground, feeding and reproducing before returning to poplars in late summer.