Attack of the Beetles

JB Damage
Damage from Japanese Beetles

This year, like always, we are facing insect issues in our lawns and gardens. It is important to remember that not all insects are bad, in fact the majority of all insects are beneficial in some way. However, when they are found in large populations or damage our plants, or both, we get concerned.

 

Soldier Beetles

Soldier Beetle
Soldier Beetle, Photo from Soni Cochran, Lancaster County Extension Assistant

Soldier beetles are common this year. These are the yellow beetles found in large quantities throughout the area this year. They are often confused with fireflies because they are both beetles without hardened elytra, like many other beetles, and they are similar in appearance. The soldier beetle we are seeing is golden in color with a black spot on each wing on the back. They are commonly found around Linden trees as well as many other flowers. There is no need to control soldier beetles because they are great pollinators and will not harm our plants or us.

Japanese Beetles

Japanese Beetle, 7-16 Acreage
Japanese beetle adult on the left side and grub on the right side, photos from Jim Kalisch, UNL Entomology

Japanese beetles have been more of a problem for southeast Nebraska over the past couple of years than they had been in the past. This is an invasive insect from Japan. Japanese beetles are problematic insects as both larvae and adults. The larvae are a type of white grub which feed on the roots of our grass, causing large brown dead spots in the turf that are easily lifted up like a rug from the floor.

Adult Japanese beetles are 7/16 inch-long, metallic green beetles. The elytra, or wing coverings, are copper. As adults, Japanese beetles feed on over 300 species of plants including trees, shrubs, fruits, vegetables, field crops, weeds, and other ornamental plant species. Some of their favorite food plants are roses, lindens, and grapes. Adult beetles feed on the foliage, flowers, and fruits of these plants. They feed on the upper surface of the leaves and cause a skeletonized pattern to the leaf where the veins of the leaf are often left behind but the rest of the leaf is chewed away. In some cases, they will consume the entire leaf. This can stress the plants, and in high populations of beetles can even kill the plant.

Grubs can be controlled with chlorantraniliprole or imidacloprid in June. Adults can be controlled with systemic insecticides such as imidacloprid or dinotefuron around Mother’s Day to give the products time to get throughout the trees and shrubs being treated. Currently, no systemic insecticides can be used on Lindens though, due to the damage to pollinators. Tempo and Bayer Advanced Lawn & Garden Multi-Insect Killer (cyfluthrin), Ortho Bug B Gone (bifenthrin), or Sevin (carbaryl) would be a few other options that can be used on Lindens and others. These options will only work for about 2 weeks so they may need to be reapplied.

Blister Beetles

blister beetles, K. Jarvi
Black and gray blister beetles, Photos by Keith Jarvi, Emeritus Extension Educator

Blister beetles were a real problem in our vegetable gardens last year, and they are back. Blister beetles are ½ inch long, powdery gray colored beetles with black antennae. They can feed on our tomato plants as well as some other vegetable crops. They can damage our plants, but they are also beneficial because they feed on grasshopper eggs. If you find them in your garden, you can treat with general insecticides such as sevin or eight. Be careful handling these beetles, some people develop blisters after handling them.

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