Mud Grub

About

Common Names: Mudgrub; Named for their larval stage these large insects are a common agricultural pest in regions where wetland or flood plain agriculture is the norm.

Classification: Arthropod, Insect
Size: 2-4 centimetres (1-2 inches)
Appearance: The adult phase of this agricultural pest is a long bodied beetle with a brown-blue iridescent shell. Larval stage is a soft fat-bodied pale blue with a distinct grey-brown head.
Sexual dimorphism: No significant visible difference between the sexes.
Variance: Multiple subspecies exist across the full range of this insect.

Habitat: Tropical to Sub-Arctic - Prairie, Grassy Wetlands
Diet: Larva - Roots and shoots of grasses and grains. Adults - Grass Leaves, Flowers, Grains, Smaller insects

Social grouping: None.
Temperament: Oblivious as larva, Skittish as adults.
Intelligence: Negligible.
Reproduction: The adults produce a unpalatable acrid musk which deters depredation. Adults remain active until the first autumn rains, at which time they mate and lay their eggs which winter in the soft mud. These eggs hatch and the grubs eat the roots and young shoots of plants until they pupate and emerge as adults during the first of the dry months.

Regional variance across the full range of these insects.

General: Considered an agricultural pest, which damages the young shoots of mudgrains and other wetland grasses. In the wild, they are prey to a host of fish, amphibians, and birds, which are less numerous in agricultural wetlands. Their depredations can ruin entire crops, so the grain patties are diligently raked before planting to remove as many as possible.
Resources: Some people will eat fried mudgrubs, supplementing a meagre spring diet with needed protein.