Once on the hop the migrants produce several generations of wingless, asexual aphids that build up in large numbers throughout the summer unless controlled. The actual aphid has a very soft body and is not hard to kill, but the tall vines and abundant leaves make it difficult to effectively spray the vine and hit all the aphids. Organic insecticides such as insecticidal soap, nicotine and diatomaceous earth work well if effectively applied. Some success can be derived via the introduction of ladybugs and lacewing predator insects as long as the predators decide to stay on the hops. The other option is to spray with a commercial insecticide such as diazinon or malathion.
Spider mites are mainly a problem in hot dry climates.
Females over-winter mainly in the soil or under leaves. In the spring they emerge and climb up the vines to feed on the lower sides of the leaves. Very small and just visible to the naked eye, their arrival is more evident by the existence of their fine white webs on the bottom of leaves. Mites are often not as big a problem as aphids, so control may not be necessary. Many of the same insecticides used on aphids are also effective on spider mites.