Beetles are insects that form the order Coleoptera, in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 described species, is the largest of all orders, constituting almost 40% of described insects and 25% of all known animal species; new species are discovered frequently, with estimates suggesting that there are between 0.9 and 2.1 million total species. Found in almost every habitat except the sea and the polar regions, they interact with their ecosystems in several ways: beetles often feed on plants and fungi, break down animal and plant debris, and eat other invertebrates. Some species are serious agricultural pests, such as the Colorado potato beetle, while others such as Coccinellidae eat aphids, scale insects, thrips, and other plant-sucking insects that damage crops.
The whirligig beetles are water beetles, comprising the family Gyrinidae that usually swim on the surface of the water if undisturbed, though they swim underwater when threatened. They get their common name from their habit of swimming rapidly in circles when alarmed, and are also notable for their divided eyes which are believed to enable them to see both above and below water. The family includes some 700 extant species worldwide, in 15 genera, plus a few fossil species. Most species are very similar in general appearance, though they vary in size from perhaps 3 mm to 18 mm in length. They tend to be flattened and rounded in cross section, in plain view as seen from above, and in longitudinal section. In fact their shape is a good first approximation to an ellipsoid, with legs and other appendages fitting closely into a streamlined surface. Whirligig beetles belong to the beetle suborder Adephaga, which also includes ground beetles and diving beetles.
A water beetle is a generalized name for any beetle that is adapted to living in water at any point in its life cycle. Most water beetles can only live in fresh water, with a few marine species that live in the intertidal zone or littoral zone. There are approximately 2000 species of true water beetles native to lands throughout the world.
Dytiscus is a Holarctic genus of predaceous diving beetles that usually live in wetlands and ponds. There are 26 species in this genus distributed in Europe, Asia, North Africa and North and Central America. They are predators that can reduce mosquito larvae.
The Adephaga are a suborder of beetles, and with more than 40,000 recorded species in 10 families, the second-largest of the four beetle suborders. Members of this suborder are collectively known as adephagans. The largest family is Carabidae which comprises most of the suborder with over 40,000 species. Adephaga also includes a variety of aquatic beetles, such as predaceous diving beetles and whirligig beetles.
Amphizoa is a genus of aquatic beetles in the suborder Adephaga, placed in its own monogeneric family, Amphizoidae. There are five known species of Amphizoa, three in western North America and two in the eastern Palearctic. They are sometimes referred to by the common name troutstream beetles.
The Dytiscidae – based on the Greek dytikos (δυτικός), "able to dive" – are the predaceous diving beetles, a family of water beetles. They occur in virtually any freshwater habitat around the world, but a few species live among leaf litter. The adults of most are between 1 and 2.5 cm (0.4–1.0 in) long, though much variation is seen between species. The European Dytiscus latissimus and Brazilian Megadytes ducalis are the largest, reaching up to 4.5 cm (1.8 in) and 4.75 cm (1.9 in) respectively. In contrast, the smallest is likely the Australian Limbodessus atypicali of subterranean waters, which only is about 0.9 mm (0.035 in) long. Most are dark brown, blackish, or dark olive in color with golden highlights in some subfamilies. The larvae are commonly known as water tigers due to their voracious appetite. They have short, but sharp mandibles and immediately upon biting, they deliver digestive enzymes into prey to suck their liquefied remains. The family includes more than 4,000 described species in numerous genera.
The Lymexylidae, also known as ship-timber beetles, are a family of wood-boring beetles. Lymexylidae belong to the suborder Polyphaga and are the sole member of the superfamily Lymexyloidea.
Cleridae are a family of beetles of the superfamily Cleroidea. They are commonly known as checkered beetles. The family Cleridae has a worldwide distribution, and a variety of habitats and feeding preferences.
Hungerford's crawling water beetle is a critically endangered member of the family Haliplidae of water beetles found in northeastern North America. The US Fish and Wildlife Service Draft Recovery Plan for the species published in August 2004 estimates roughly 1000 individuals are present in the wild. In 2010, a five-year summary report by the United States Fish and Wildlife Service found the population to be essentially unchanged.
Bucolus fourneti is a native Australian, small, hairy coccinellid beetle approximately 2.1-4.5 mm in diameter. It was described by Étienne Mulsant in 1850
Peltodytes tortulosus is a species of crawling water beetle in the family Haliplidae. It is found in North America.
Peltodytes edentulus is a species of crawling water beetle in the family Haliplidae. It is found in North America.
Aspidytidae is a family of aquatic beetles of the suborder Adephaga, described in 2002 from specimens in South Africa and China. There are only two known species in the family and these were originally described in the genus Aspidytes, but later the new genus Sinaspidytes was erected for the species found in China. The family can also be referred to by its trivial name cliff water beetles.
Hydroglyphus flammulatus, is a species of predaceous diving beetle found in India, Sri Lanka, Pakistan, Thailand, Cambodia, China, Taiwan, Korea, Myanmar, Bangladesh, Indonesia, Vietnam, and Nepal.
Hydaticus vittatus, is a species of predaceous diving beetle found in India, Pakistan, Sri Lanka, Nepal, Bangladesh, Bhutan, Myanmar, China, Japan, Taiwan, Thailand, Cambodia, Laos, Vietnam, Malaysia and Indonesia.
Cybister tripunctatus, is a species of predaceous diving beetle found in India, Andaman & Nicobar Islands, Sri Lanka, Afghanistan, Bangladesh, Myanmar, Nepal, Pakistan, Bhutan, China, Cyprus, Iran, Iraq, Japan, Kyrgyzstan, Mongolia, Russia, Syria, Tajikistan, Turkmenistan, Italy, Turkey, Uzbekistan and Europe.
Herophydrus musicus, is a species of predaceous diving beetle found in Asia and Europe.
Laccophilus wolfei, is a species of predaceous diving beetle found in India and Sri Lanka.
Rhantus suturalis, commonly known as the supertramp beetle or cosmopolitan diving beetle, is a species of diving beetle (Dytiscidae) with a cosmopolitan distribution.
