False Japanese Beetle: Appearance, Territory, Damage and Life Cycle

Latin Name: Strigoderma Arboricola

Appearance: Several calls and samples from eastern Iowa counties indicate that the fake Japanese beetle, Strigoderma Arbicola, is having another “banner year.” The fake Japanese beetle is a Junebug that bears a passing similarity to the well-known imported pest, the Japanese beetle. A comparison of diagnostic features is shown in the table below.

This species, often known as a sandhill chafer, is frequently confused with the Japanese beetle. They have a similar body form and size (half an inch in length), however they are not shiny green and golden. They may have white hair on the sides of their abdomen, but it is more uniformly distributed rather than in tufts. False Japanese beetles reproduce once a year. Adults eat on the flowers, fruits, and leaves of a wide variety of plants, although they are not regarded a field crop pest.

Hosts Plants: Soyabean Fields and Fower Garden

Territory: It was unintentionally introduced into the United States from Japan in 1916, most likely as larvae in the soil near imported plants. Japanese beetles have been seen feeding on over 200 plant species, including a wide range of trees, shrubs, grasses, and nursery plants.

Damage Insect Cause: False Japanese beetles may be a major nuisance in soybean fields and flower gardens. The insects eat on the leaves and leave big, uneven holes in the foliage, blooms, and buds. Damage to white and yellow roses and other flowers is very prevalent.

Life History and Habits: Adult beetles are normally only present for two weeks in late June and early July, when they mate and deposit eggs in the soil. The larvae are white grubs that feed on plant roots in the soil of grassy, sandy places. In Iowa, they have not been reported as a soil pest. Each year, there is just one generation. If the infestations are minor, handpick the beetles in the garden, or try cloth coverings for high-value plants (for example, screening over individual rose bushes). Garden pesticides can be applied, but the results may be disappointing since insecticide residues may not control newly arrived beetles. Sprays are likely to be more effective than dusts.