Thermonectus marmoratus
Encyclopedia
Thermonectus marmoratus is a species of diving beetle
known by the common names sunburst diving beetle and spotted diving beetle. The beetle has recently become notable when it was discovered that its aquatic larval stage has been found to have used in its principal eyes two retina
s and two distinct focal planes that are substantially separated, in the manner of bifocals to switch their vision from up-close to distance, for easy and efficient capture of their prey, mostly mosquito
larvae. This is the first ever recorded use of bifocal technology
in the animal world.
covered with bright yellow or golden spots. The male has a suction disk on each foreleg.
Sunburst diving beetles are found in extreme Southern California
, Arizona
, New Mexico
, Texas
, and Mexico
, requiring at least a temporary water source.
larvae and pupae. Spotted diving beetles have also been observed swarming a prey item and feeding en masse. In captivity, these beetles will feed on flake fish food and live crickets.
Dytiscidae
Dytiscidae – based on the Greek dytikos , "able to dive" – are the predaceous diving beetles, a family of water beetles. They are about 25 mm long on average, though there is much variation between species. Dytiscus latissimus, the largest, can grow up to 45 mm long...
known by the common names sunburst diving beetle and spotted diving beetle. The beetle has recently become notable when it was discovered that its aquatic larval stage has been found to have used in its principal eyes two retina
Retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...
s and two distinct focal planes that are substantially separated, in the manner of bifocals to switch their vision from up-close to distance, for easy and efficient capture of their prey, mostly mosquito
Mosquito
Mosquitoes are members of a family of nematocerid flies: the Culicidae . The word Mosquito is from the Spanish and Portuguese for little fly...
larvae. This is the first ever recorded use of bifocal technology
Bifocals
Bifocals are eyeglasses with two distinct optical powers. Bifocals are most commonly prescribed to people with presbyopia who also require a correction for myopia, hyperopia, and/or astigmatism.-History:...
in the animal world.
Description
The adult beetle reaches a maximum length of about one centimeter, or half an inch, with females slightly larger than males. The sunburst diving beetle has a black and streamlined carapaceCarapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
covered with bright yellow or golden spots. The male has a suction disk on each foreleg.
Behavior and distribution
Sunburst diving beetles live in ponds and lakes and swim well. When their water source dries up they will fly to a new one.Sunburst diving beetles are found in extreme Southern California
Southern California
Southern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include Greater Los Angeles and Greater San Diego. The urban area stretches along the coast from Ventura through the Southland and Inland Empire to San Diego...
, Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
, Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, requiring at least a temporary water source.
Diet
In the wild, these beetles are useful because they eat other invertebrates including mosquitoMosquito
Mosquitoes are members of a family of nematocerid flies: the Culicidae . The word Mosquito is from the Spanish and Portuguese for little fly...
larvae and pupae. Spotted diving beetles have also been observed swarming a prey item and feeding en masse. In captivity, these beetles will feed on flake fish food and live crickets.