Tropisternus lateralis

Tropisternus lateralis is a species of hydrophilid beetle that ranges across much of the Americas.

Description
Adult T. lateralis nimabatus, the subspecies found in the eastern United States, are distinguished by having uniformly dark elytra and pronotum with light-colored borders.

Distribution
The range of T. lateralis includes North America as far north as southern Canada, South America south to northern Chile and Argentina, the Caribbean, and the Galápagos Islands. T. lateralis humeralis has been accidentally introduced to Oahu.

Behavior
T. lateralis exhibits stridulation during stress, calling, and courtship. Eggs are deposited in cases under water, and larvae are fully aquatic. While adults are primarily aquatic, they breathe air and can fly. Adult T. lateralis avoid colonizing and laying egg cases in ponds that contain fish, which are potential predators of all life stages of the beetles.

Subspecies
There are five recognized subspecies of Tropisternus lateralis.
 * T. lateralis humeralis Motschulsky, 1850
 * T. lateralis lateralis (Fabricius, 1775)
 * T. lateralis limbalis (LeConte, 1855)
 * T. lateralis limbatus (Brullé, 1837)
 * T. lateralis nimbatus (Say, 1823)