Water beatle.....

[J Darcy 5,871]

Found this yesterday....thought it was a great diving beatle, but the carapace looks different..... can anyone tell me what it is...from memory i just cannot pin it down...is there such a thing as a lesser diving beatle??

[talpa 55]

Found this yesterday....thought it was a great diving beatle, but the carapace looks different..... can anyone tell me what it is...from memory i just cannot pin it down...is there such a thing as a lesser diving beatle??

 

I think you were on the right track with your first hunch.

It looks very much like you have a female Great Diving Beetle, they are sexually dimorphic. The elytra of the male has fewer ridges on it and the first pair of legs are different ( probably designed for grasping the thorax of females ((like male Frogs/Toads thumbs)) but the first pair of legs are missing or not visible on your pics. Often get calls from people reporting cockroachs when they find them inside after being drawn in by lights at night. Sometimes find them in Electric Fly Killers too.

talpa

[martin 332]

Certainly looks like a 'Great Diving Beetle' J.D...........................Martin.

[J Darcy 5,871]

The ones i have had before have been a tad bigger. Several years ago i captured a larvae and studied it , watching it grow on a diet of tadpoles. 3 an hour it ate, both frog and toad. Once it became large enough it crawled out of the water and i was lucky enough to see it bury itself in a small layer of compost i had provided. I would have thought this emergence would have happened whether at daybreak or through the night, but it was in the daytime. Sadley the story doesnt have a happy ending for i noticed the larvae had been underground for a good while so i carefully has a little scrape back of the compost only to find the lavae, well developed, was a writhing mass of tiny maggots. I was most disapointed indeed. still it was a great experience

[martin 332]

The ones i have had before have been a tad bigger. Several years ago i captured a larvae and studied it , watching it grow on a diet of tadpoles. 3 an hour it ate, both frog and toad. Once it became large enough it crawled out of the water and i was lucky enough to see it bury itself in a small layer of compost i had provided. I would have thought this emergence would have happened whether at daybreak or through the night, but it was in the daytime. Sadley the story doesnt have a happy ending for i noticed the larvae had been underground for a good while so i carefully has a little scrape back of the compost only to find the lavae, well developed, was a writhing mass of tiny maggots. I was most disapointed indeed. still it was a great experience

Hi,I did the same with a Hawker Dragonfly larvae in a tank in my lodgings at the time.It was fascinating watching it feed on tadpoles and small fry that I used to net in the river margins.I nearly got my marching orders when the bloody thing emerged as a dragonfly and alledgedly attacked my landlord(feckin' fat wuss).What spectacular creatures there are in our water courses.........................Martin.

[J Darcy 5,871]

The ones i have had before have been a tad bigger. Several years ago i captured a larvae and studied it , watching it grow on a diet of tadpoles. 3 an hour it ate, both frog and toad. Once it became large enough it crawled out of the water and i was lucky enough to see it bury itself in a small layer of compost i had provided. I would have thought this emergence would have happened whether at daybreak or through the night, but it was in the daytime. Sadley the story doesnt have a happy ending for i noticed the larvae had been underground for a good while so i carefully has a little scrape back of the compost only to find the lavae, well developed, was a writhing mass of tiny maggots. I was most disapointed indeed. still it was a great experience

Hi,I did the same with a Hawker Dragonfly larvae in a tank in my lodgings at the time.It was fascinating watching it feed on tadpoles and small fry that I used to net in the river margins.I nearly got my marching orders when the bloody thing emerged as a dragonfly and alledgedly attacked my landlord(feckin' fat wuss).What spectacular creatures there are in our water courses.........................Martin.

Yes i have studied Southern hawkers and broad bodies chasers quite closely. They are most amazing creatures. also at one time i was quite obsessed with amphibians. i used to be able to feed the great crested newts in my pond from my fingers, got pics to prove it. They are a very lovely creature. I wish i had digital cameras back then as the pics would have been awesome! I think i took 12 rolls of flim to get the shot i wanted, a GCN emerging through the water surface film to take a breath, his beady eyes looking at me from above the water. Those southern hawkers were amazing to watch and i took many sequence shots of them emeging and drying out prior to take off.

[talpa 55]

The ones i have had before have been a tad bigger. Several years ago i captured a larvae and studied it , watching it grow on a diet of tadpoles. 3 an hour it ate, both frog and toad. Once it became large enough it crawled out of the water and i was lucky enough to see it bury itself in a small layer of compost i had provided. I would have thought this emergence would have happened whether at daybreak or through the night, but it was in the daytime. Sadley the story doesnt have a happy ending for i noticed the larvae had been underground for a good while so i carefully has a little scrape back of the compost only to find the lavae, well developed, was a writhing mass of tiny maggots. I was most disapointed indeed. still it was a great experience

Hi,I did the same with a Hawker Dragonfly larvae in a tank in my lodgings at the time.It was fascinating watching it feed on tadpoles and small fry that I used to net in the river margins.I nearly got my marching orders when the bloody thing emerged as a dragonfly and alledgedly attacked my landlord(feckin' fat wuss).What spectacular creatures there are in our water courses.........................Martin.

Yes i have studied Southern hawkers and broad bodies chasers quite closely. They are most amazing creatures. also at one time i was quite obsessed with amphibians. i used to be able to feed the great crested newts in my pond from my fingers, got pics to prove it. They are a very lovely creature. I wish i had digital cameras back then as the pics would have been awesome! I think i took 12 rolls of flim to get the shot i wanted, a GCN emerging through the water surface film to take a breath, his beady eyes looking at me from above the water. Those southern hawkers were amazing to watch and i took many sequence shots of them emeging and drying out prior to take off.

 

 

Hi, if you have seen bigger GDBeetles befor eit may be that they were Dytiscus latissimus (no common name) which are a bigger cousin of the GD Beetles they are bigger all over by about 25% and much broader at the half way point on length of their elytra making them look more egg shaped. Which would probably mean they should be called Greater GD Beetles??

talpa