Most Common Hop Plant Pests:
Identification and Treatment Guide

Hop plants (Humulus lupulus) are an essential ingredient in the brewing industry, adding flavor, aroma, and bitterness to beer. However, like any other plant, hop plants are susceptible to various pests that can cause damage and reduce yields. Identifying these pests and implementing effective treatment strategies is crucial for maintaining healthy hop plants and maximizing crop production. In this article, we will discuss some of the most common hop plant pests, their identification, and treatment options.

Aphids

Aphids are small, soft-bodied insects that feed on the sap of hop plants. They can be found on the undersides of leaves and along the stems. Aphids reproduce rapidly and can quickly infest a hop plant if left untreated. Some common species of aphids that affect hop plants include green peach aphids (Myzus persicae) and potato aphids (Macrosiphum euphorbiae).

Identification: Aphids are usually less than 1/8 inch long and come in various colors such as green, yellow, or black. They have pear-shaped bodies with long antennae and cornicles (small tubes) protruding from their abdomen.

Treatment: There are several treatment options for aphid control in hop plants. One effective method is to introduce natural predators like ladybugs or lacewings to the hop yard. These beneficial insects feed on aphids and can help keep their populations in check. Additionally, spraying insecticidal soaps or neem oil on infested plants can also provide control.

Spider Mites

Spider mites are tiny arachnids that feed on the fluids within hop plant cells. They are common pests in hot and dry climates, as they thrive in such conditions. Spider mites prefer the undersides of leaves and spin fine silk webs as they move around the plant.

Identification: Spider mites are extremely small, usually less than 1/20 inch long. They can be red, green, or yellow in color. When present in large numbers, spider mites can cause visible discoloration and stippling on hop leaves.

Treatment: Controlling spider mites can be challenging due to their rapid reproduction rate and ability to develop resistance to pesticides. However, regular monitoring and early detection are key to effective treatment. Spraying the plants with a strong jet of water can help dislodge and remove spider mites. In severe cases, applying insecticidal soaps or miticides may be necessary.

Hop Flea Beetle

Hop flea beetles (Psylliodes punctulata) are small, shiny black beetles that feed on hop leaves. They chew small holes in the foliage, leading to a characteristic shot-hole appearance. The damage caused by hop flea beetles can weaken the plant and reduce yields.

Identification: Hop flea beetles are about 1/8 inch long and have enlarged hind legs, which allow them to jump when disturbed. They have a shiny black body with a slightly elongated shape.

Treatment: Preventive measures like installing physical barriers such as row covers or mesh netting can help protect hop plants from flea beetles. If infestation occurs, applying insecticides labeled for flea beetle control can provide control.

Japanese Beetle

The Japanese beetle (Popillia japonica) is an invasive pest that feeds on more than 300 different plant species, including hop plants. These beetles skeletonize the leaves by consuming the tissue between the veins.

Identification: Japanese beetles are about 1/2 inch long and have a metallic green body with copper-colored wings. They have distinctive white tufts of hair along the sides of their abdomen.

Treatment: Several treatment options are available for controlling Japanese beetles. Handpicking and physically removing the beetles from the plants can be effective for small infestations. In larger hop yards, applying insecticides labeled for Japanese beetle control is recommended.

Two-Spotted Spider Mite

The two-spotted spider mite (Tetranychus urticae) is another species of spider mite that commonly infests hop plants. They are named after the two dark spots present on their back. Two-spotted spider mites feed on the sap of leaves, causing discoloration, webbing, and leaf drop.

Identification: Two-spotted spider mites are about 1/50 inch long and can vary in color from light yellow to green or red. They have eight legs and are typically found on the undersides of leaves.

Treatment: Similar to other spider mites, controlling two-spotted spider mites requires regular monitoring and early intervention. Spraying plants with a strong jet of water can help dislodge and reduce mite populations. If necessary, applying miticides labeled for spider mite control can be effective.

Conclusion

Maintaining healthy hop plants requires vigilant pest management strategies. Identifying common hop plant pests and implementing appropriate treatment options is essential for protecting the crop and maximizing yields. Regular monitoring, early detection, and integrated pest management practices should be employed to minimize the impact of pests on hop plants. By following these guidelines, hop growers can ensure the health and productivity of their hop yards for years to come.