Great diving beetle

Dytiscus marginalis

The great diving beetle, Dytiscus marginalis, is a large aquatic diving beetle native to Europe and northern Asia, and is particularly common in England. The great diving beetle, true to its name, is a rather sizable insect. The larvae can grow up to 60 millimetres (2.4 in) in length, while the adults are generally between 27–35 millimetres.
Great diving beetle larva Definitely one of the most voracious killers in a pond. They will eat everything that moves. For this picture i caught two of them and put them in my small 'photo aquarium' but sadly after a few minutes i only had this one (the smaller one) left with a body that suddenly was not so transparent anymore, and also a lot bigger. At least he had a good dinner before returning to the pond! :) Dytiscus marginalis,Geotagged,Great diving beetle,Larvae,Netherlands,Summer,larva,water beetle

Appearance

They are dark-coloured (brown to black) on their back and wing cases (elytra) and yellow on their abdomen and legs. The male's wing cases are shiny, while those of the female are finely grooved.
Great diving beetle - Dytiscus marginalis (larva) Doode Bemde, Oud-Heverlee, Belgium (May 2019). 
http://www.environmentdata.org/archive/fbaia:2570

For a view of her home pond see:
https://www.jungledragon.com/image/125510 Belgium,Dytiscus marginalis,Geotagged,Great diving beetle,Spring

Behavior

They are able fliers, and fly usually at night. They use the reflection of moonlight to locate new water sources. This location method can sometimes cause them to land on wet roads or other hard wet surfaces.

Before they dive, they collect air bubbles in their wing cases which goes through the spiracles. The jaws of a great diving beetle are strong compared to their body size.
Great diving beetle larva Definitely one of the most voracious killers in a pond. They will eat everything that moves. For this picture i caught two of them and put them in my small 'photo aquarium' but sadly after a few minutes i only had this one (the smaller one) left with a body that suddenly was not so transparent anymore, and also a lot bigger. At least he had a good dinner before returning to the pond! :) Dytiscus marginalis,Geotagged,Great diving beetle,Netherlands,Summer,larva

Habitat

These beetles live in fresh water, either still or slow-running, and seem to prefer water with vegetation.
Great diving beetle (female) and common water strider This is the first time I've seen a diving beetle. Unfortunately, this one is dead, which I learned after flipping it over. Because of the ridged shield, this likely is a female. They are quite aggressive and capable predators, both as larvae and as adults. What amazes me most is that they can still fly, I did not expect that. Dytiscus marginalis,Geotagged,Great diving beetle,Heesch,Macro,The Netherlands

Food

A voracious predator, this beetle hunts a wide variety of prey including small fish.

References:

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Status: Unknown
EX EW CR EN VU NT LC
Taxonomy
KingdomAnimalia
DivisionArthropoda
ClassInsecta
OrderColeoptera
FamilyDytiscidae
GenusDytiscus
Species
Photographed in
Belgium
Netherlands