Home / Scarab Beetles (Scarabaeidae) / Asiatic Garden Beetle (Maladera castanea)

Asiatic Garden Beetle (Maladera castanea)

Asiatic garden beetle is a part of the scarab beetle (Scarabaeidae) family indigenous to China and Japan. It was spotted in the United States, New Jersey in particular, in the 1920s, regarded a pest there, mostly damaging field crops and grasses.

Asiatic Garden Beetle

Scientific Classification

  • Family: Scarabaeidae
  • Genus: Maladera
  • Scientific name: Maladera castanea

Physical Description and Identification

Adult

Size: 9.57 mm (0.37 inches)

Color: It has a cinnamon brown or copper coloration with a velvety appearance. The presence of short yellow hairs are seen in an irregular pattern on the undersides of their thorax.

Other Characteristic Features: As small as the size of a coffee bean, it appears domed or plump, with the abdomen protruding a little from its wing covers. They even have broader and larger hind legs.

Larva

The matured larva grub about 12.7 mm (0.5 inches) long has a C-shaped white body and brown head, marked with a series of curved spines on its undersides.

Asiatic Garden Beetle Larvae
Asiatic Garden Beetle Grubs

Pupa

The pupation stage commences between May and June, with the pupa being white initially and eventually turning to tan by the last larval stage. They grow between 7.93 and 9.5 mm (0.31 – 0.37 inches) in length. The pupal stage lasts for not more than 8 – 15 days.

Egg

The females lay about 60 eggs in a week in clusters of 3 – 15. They are oval at the onset, becoming spherical upon getting absorbed in water.

Quick Facts

LifespanAbout a month
DistributionNative: Japan and China
Non-native: The northeastern United Statesand parts of eastern Canada, having a wide and extensive range, touching upon the regions of New England, Ohio, Kansas, Alabama, Georgia, Missouri, South Carolina
HabitatLarva: Grassy areas mostly in vegetable or flower gardens where the soil is moist, loamy, and sandy
Adult: Mostly in fields, deciduous forest areas, and everywhere else where there host plant grows
Common PredatorsSpiders, wasps, bugs, birds
Seasons active fromLate June – late October 
Host PlantsLarvae: Grass, weed, corn, soybean potato
Adults: Cherry, turnip pepper, rose, dahlia, and eggplant (few of the 100 types of plants they feed on)
Diet  of larvae and adultsLarvae: Roots of several plants like corn, sweet potato, and soybean, as well as grass  
Adults: Feed on more than 100 different kinds of plants like leaves of cherry, peach, viburnum, boxelder, carrot, eggplant, turnip, pepper; fruits; flowers like rose, dahlia, aster as well as herbs  
Maladera castanea

Identifying the Damage Caused by Them

The adult beetles feed at night, stripping and shedding their host plant’s foliage, reducing them to bits, with only the midrib remaining in the case of heavy feeding.

On the other hand, the larva has a more scattered diet pattern since it feeds in several depths. It does cause damage to the turf and roots, but at a lesser intensity than the adults.

Did You Know

  • The adult Asiatic Garden Beetle species are nocturnal, leaving their hideouts at dusk and setting out to search their host plants.
  • They are bad swimmers, and placing them in a soapy water container could take a toll on their life.
  • Of the several management techniques applied to control their numbers, placing floating row covers over ornamental plants or even corn or other vegetable fields could be one of the measures.
  • They are strongly attracted towards the light, present in large numbers in brightly lit up areas. So, a light trap or flashlight may help in handpicking these beetles at night. 
Asiatic Garden Beetle Picture

Image Source: a4.pbase.com, cfaes.osu.edu, content.ces.ncsu.edu, bugguide.net, content.eol.org

Asiatic garden beetle is a part of the scarab beetle (Scarabaeidae) family indigenous to China and Japan. It was spotted in the United States, New Jersey in particular, in the 1920s, regarded a pest there, mostly damaging field crops and grasses.

Asiatic Garden Beetle

Physical Description and Identification

Adult

Size: 9.57 mm (0.37 inches)

Color: It has a cinnamon brown or copper coloration with a velvety appearance. The presence of short yellow hairs are seen in an irregular pattern on the undersides of their thorax.

Other Characteristic Features: As small as the size of a coffee bean, it appears domed or plump, with the abdomen protruding a little from its wing covers. They even have broader and larger hind legs.

Larva

The matured larva grub about 12.7 mm (0.5 inches) long has a C-shaped white body and brown head, marked with a series of curved spines on its undersides.

Asiatic Garden Beetle Larvae
Asiatic Garden Beetle Grubs

Pupa

The pupation stage commences between May and June, with the pupa being white initially and eventually turning to tan by the last larval stage. They grow between 7.93 and 9.5 mm (0.31 – 0.37 inches) in length. The pupal stage lasts for not more than 8 – 15 days.

Egg

The females lay about 60 eggs in a week in clusters of 3 – 15. They are oval at the onset, becoming spherical upon getting absorbed in water.

Quick Facts

LifespanAbout a month
DistributionNative: Japan and China
Non-native: The northeastern United Statesand parts of eastern Canada, having a wide and extensive range, touching upon the regions of New England, Ohio, Kansas, Alabama, Georgia, Missouri, South Carolina
HabitatLarva: Grassy areas mostly in vegetable or flower gardens where the soil is moist, loamy, and sandy
Adult: Mostly in fields, deciduous forest areas, and everywhere else where there host plant grows
Common PredatorsSpiders, wasps, bugs, birds
Seasons active fromLate June – late October 
Host PlantsLarvae: Grass, weed, corn, soybean potato
Adults: Cherry, turnip pepper, rose, dahlia, and eggplant (few of the 100 types of plants they feed on)
Diet  of larvae and adultsLarvae: Roots of several plants like corn, sweet potato, and soybean, as well as grass  
Adults: Feed on more than 100 different kinds of plants like leaves of cherry, peach, viburnum, boxelder, carrot, eggplant, turnip, pepper; fruits; flowers like rose, dahlia, aster as well as herbs  
Maladera castanea

Identifying the Damage Caused by Them

The adult beetles feed at night, stripping and shedding their host plant’s foliage, reducing them to bits, with only the midrib remaining in the case of heavy feeding.

On the other hand, the larva has a more scattered diet pattern since it feeds in several depths. It does cause damage to the turf and roots, but at a lesser intensity than the adults.

Did You Know

  • The adult Asiatic Garden Beetle species are nocturnal, leaving their hideouts at dusk and setting out to search their host plants.
  • They are bad swimmers, and placing them in a soapy water container could take a toll on their life.
  • Of the several management techniques applied to control their numbers, placing floating row covers over ornamental plants or even corn or other vegetable fields could be one of the measures.
  • They are strongly attracted towards the light, present in large numbers in brightly lit up areas. So, a light trap or flashlight may help in handpicking these beetles at night. 
Asiatic Garden Beetle Picture

Image Source: a4.pbase.com, cfaes.osu.edu, content.ces.ncsu.edu, bugguide.net, content.eol.org

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