In the final stages the leaves wither to an ashy-gray color and fall. There may be a marginal scorch on the older leaves. Your best defense is to check your plants daily or even twice daily, morning and evening, especially in the early stages of growth. Problems can be corrected and damage reduced if caught early. A frequent pest on hops.
Winged aphids move to the top of the plant late in the spring.
Aphid populations may build very rapidly and if left uncontrolled may result in defoliation. A serious pest of hops grown in the warm interior valleys of the northwestern United States. Mite webs protect eggs and mobile mites from contact by sprays. Webbing is usually confined to the main interveinal areas of the underside of the leaf. Mites damage hop leaves by inserting needle-like mouthparts into plant cells and pumping out the contents.