Dytiscus

Linnaeus, 1758

predaceous diving beetles

Species Guides

12

Dytiscus is a Holarctic of large predaceous diving beetles comprising 26 . range 2.2–4.4 cm in length and are fully aquatic, breathing air collected under their . Both adults and larvae are active . The genus has been observed to reduce mosquito larva in wetland .

Dytiscus carolinus by (c) Matthew Pintar, some rights reserved (CC BY), uploaded by Matthew Pintar. Used under a CC-BY license.Dytiscus carolinus by (c) Samuel Paul Galick, some rights reserved (CC BY), uploaded by Samuel Paul Galick. Used under a CC-BY license.Dytiscus dauricus by (c) Louis Imbeau, some rights reserved (CC BY), uploaded by Louis Imbeau. Used under a CC-BY license.

Pronunciation

How to pronounce Dytiscus: //dɪˈtɪskəs//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Males distinguished from females by smooth and sucker-modified on forelegs and midlegs. Females identified by larger size and either grooved or smooth elytra. The is among the largest in Dytiscidae, with D. latissimus rivaling certain Megadytes in size. Larvae (water tigers) have elongate bodies with round, flat and grooved .

Images

Appearance

Large, robust, rounded water beetles with lengths of 2.2–4.4 cm. Males possess modified foreleg and midleg forming circular suckers used during mating. Females occur in two forms: with grooved (sulcate) or smooth ; males have only smooth elytra. have concealed under the elytra for breathing collected air.

Habitat

Wetlands, ponds, and shallow aquatic environments. Specific occupy high-altitude mountain ponds, seepage areas, densely vegetated ponds, and desert aquatic systems. and larvae are aquatic; pupae occur in soil at water margins.

Distribution

Holarctic distribution: Europe, Asia, North Africa, North America, and Central America. Documented include far eastern Russia, northern Japan, South Korea (including DMZ region), and Arizona desert regions.

Diet

Predatory. and larvae prey on other aquatic . Larvae possess mandibular grooves through which they suck body fluids of prey.

Life Cycle

laid inside tissue of aquatic plants such as reeds, hatching in approximately three weeks. Larvae (water tigers) are elongate with round, flat and strong, grooved ; they obtain air from the water surface using abdominal hairs leading to . Mature larvae move to soil at water edges, burrow into , and pupate. breathe by surfacing and upending to collect air under .

Behavior

of most can fly. Males use sucker-modified to grip females during mating. Adults regularly surface to replenish air supply stored under . Larvae are active that hunt aquatic prey.

Ecological Role

that regulates of other aquatic including mosquito larvae. Used as bioindicator for assessing health of aquatic environments.

Human Relevance

agent for mosquito . Subject of ecological and genetic research including mitogenome studies.

Similar Taxa

  • MegadytesSimilar large size; D. latissimus matches certain Megadytes in dimensions. Megadytes lacks the male tarsal suckers characteristic of Dytiscus.
  • Other Dytiscidae generaDytiscus distinguished by combination of large size, male tarsal suckers, and female dimorphism in elytral .

More Details

Parasitoids

are parasitized by in Eulophidae, Mymaridae, and other Chalcidoidea.

Etymology

Name derived from Greek δυτικός ('able to dive') with diminutive suffix -ίσκος, meaning 'little diver'.

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Sources and further reading