Disease: Asparagus aphid
Pathogen: Brachycorynella asparagi Host Crops: Asparagus aphids spend their entire life cycle on asparagus. The egg stage overwinters on foliage. Eggs hatch in early spring to produce wingless ‘stem mothers’. The latter produce multiple generations of winged and wingless aphids in spring and summer. The sexual stage forms in the fall, when eggs are also laid. Aphids feed on ferns and can stunt growth of asparagus. Feeding on mature ferns can lead to tufting of growth beyond the point of injury. Newly emerging shoots then have short internodes, producing a clump of dense growth.
Damage to an asparagus fern caused by the asparagus aphid.
Photo Source: Karen Ward, Washington State University