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Oriental Beetle (Anomala orientalis)

Oriental beetle of the scarab beetle family and shining leaf chafer subfamily is a native of Asia also thriving in North America as an invasive species.

Oriental Beetle

Scientific Classification

  • Family: Scarabaeidae
  • Genus: Anomala
  • Scientific name: Anomala orientalis

Physical Description and Identification

Adult

Size: 9.5 – 11.11 mm (0.37 – 0.43 inches)

Color: They are either mottled black, solid black, or brown.

Other Characteristic Features: They have markings of black on their elytra and abdomen.

Anomala orientalis

Larva

The white C-shaped larvae grow to approximately 19.05 mm (0.75 inches) long. They are regarded closely similar to the Japanese beetle, but for the arrangement of spines. In fact, in the Oriental beetle, the spines occur in parallel rows, seen only under a hand lens, whereas in the Japanese beetle, the spines are v-shaped.

When newly hatched, they feed on rootlets, tuft grasses, and even organic matter. In the summer, they mostly remain on top of the soil and go deeper to overwinter. When the soil gets warm in spring, the grubs again ascend and reach the upper layers and feed for about five weeks. Then they go back to the tunnel they have made to spend the pupation period.

Oriental Beetle Larva

Pupa

In the prepupal stage, the larvae appear flaccid and wrinkled. When matured, the pupa grows to about 10mm (0.39 inches) in length and 5 mm (0.19 inches) in width.

Egg

The small, milky white eggs are laid in the soil, where the female Oriental beetle makes a burrow, 2 to 4 inches deep. They are oval at the beginning, gradually turning spherical as they mature and get ready for hatching.

Oriental Beetle Eggs

Quick Facts

Adult lifespan1 – 2 weeks
Duration of larval stage5 – 6 weeks
DistributionNative: Throughout Asia
Invasive: Parts of North America touching parts of Ohio, Wisconsin, North Carolina, South Carolina, Massachusetts, and Maine
HabitatGardens, forests, nurseries, and all other places where their host plants inhabit
Common PredatorsFlies, spiders, bugs, birds
Seasons active fromJuly – September
Host PlantsRoses, daisies, phlox, hollyhock, and petunia
Diet  of larvae and adults Larvae: Mostly roots of different varieties of grasses, alongside fruits (strawberries, cranberries), and ornamental plants (kept in nurseries)
Adults: Flower petals

Identifying the Damage Caused by Them

The larvae do cause a significant amount of damage to the roots and ornamental plants kept in nurseries hampering their growth and resulting in the plant’s death eventually. The adults mostly attack the flower petals, particularly of daisies, but the damage caused by them is not too significant.

Did You Know

  • Of the several measures used to control or eliminate oriental beetles, one of them includes setting sex pheromone traps for them. 
  • Besides the differences in the larvae of the Oriental and Japanese beetles, the adults vary, too, especially when it comes to color. The former is mostly black, while the latter appears metallic red or green. Moreover, the Oriental beetle is less seen than the Japanese beetle as it mostly flies at night and has less appetite.
Oriental Beetle Image

Image Source: a4.pbase.com, discoverlife.org, bugwoodcloud.org, bugguide.net

Oriental beetle of the scarab beetle family and shining leaf chafer subfamily is a native of Asia also thriving in North America as an invasive species.

Oriental Beetle

Physical Description and Identification

Adult

Size: 9.5 – 11.11 mm (0.37 – 0.43 inches)

Color: They are either mottled black, solid black, or brown.

Other Characteristic Features: They have markings of black on their elytra and abdomen.

Anomala orientalis

Larva

The white C-shaped larvae grow to approximately 19.05 mm (0.75 inches) long. They are regarded closely similar to the Japanese beetle, but for the arrangement of spines. In fact, in the Oriental beetle, the spines occur in parallel rows, seen only under a hand lens, whereas in the Japanese beetle, the spines are v-shaped.

When newly hatched, they feed on rootlets, tuft grasses, and even organic matter. In the summer, they mostly remain on top of the soil and go deeper to overwinter. When the soil gets warm in spring, the grubs again ascend and reach the upper layers and feed for about five weeks. Then they go back to the tunnel they have made to spend the pupation period.

Oriental Beetle Larva

Pupa

In the prepupal stage, the larvae appear flaccid and wrinkled. When matured, the pupa grows to about 10mm (0.39 inches) in length and 5 mm (0.19 inches) in width.

Egg

The small, milky white eggs are laid in the soil, where the female Oriental beetle makes a burrow, 2 to 4 inches deep. They are oval at the beginning, gradually turning spherical as they mature and get ready for hatching.

Oriental Beetle Eggs

Quick Facts

Adult lifespan1 – 2 weeks
Duration of larval stage5 – 6 weeks
DistributionNative: Throughout Asia
Invasive: Parts of North America touching parts of Ohio, Wisconsin, North Carolina, South Carolina, Massachusetts, and Maine
HabitatGardens, forests, nurseries, and all other places where their host plants inhabit
Common PredatorsFlies, spiders, bugs, birds
Seasons active fromJuly – September
Host PlantsRoses, daisies, phlox, hollyhock, and petunia
Diet  of larvae and adults Larvae: Mostly roots of different varieties of grasses, alongside fruits (strawberries, cranberries), and ornamental plants (kept in nurseries)
Adults: Flower petals

Identifying the Damage Caused by Them

The larvae do cause a significant amount of damage to the roots and ornamental plants kept in nurseries hampering their growth and resulting in the plant’s death eventually. The adults mostly attack the flower petals, particularly of daisies, but the damage caused by them is not too significant.

Did You Know

  • Of the several measures used to control or eliminate oriental beetles, one of them includes setting sex pheromone traps for them. 
  • Besides the differences in the larvae of the Oriental and Japanese beetles, the adults vary, too, especially when it comes to color. The former is mostly black, while the latter appears metallic red or green. Moreover, the Oriental beetle is less seen than the Japanese beetle as it mostly flies at night and has less appetite.
Oriental Beetle Image

Image Source: a4.pbase.com, discoverlife.org, bugwoodcloud.org, bugguide.net

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