Green dock leaf beetles

 There are lots of broad-leaved dock Rumex obtusifolius plants around at the moment with foliage that looks like this, resembling green lace.

It's the handiwork of the larvae of the green dock leaf beetle Gastrophysa viridula - turn over a leaf where damage is just beginning and you'll find several on the underside, eating the soft tissue between the leaf veins. When fully fed they burrow down into the soil and pupate, emerging as adult beetles within a couple of weeks.

And here are the rather beautiful adult leaf beetles, mating. The abdomen of the female is so distended with eggs that it displaces her wing cases. She'll lay as many as 1000 eggs and, with a short generation time, the numbers of these insects can rise rapidly as summer progresses.

Exploring the undergrowth

I spent a couple of hours last week, on a warm, humid afternoon, exploring the undergrowth at Deepdale Nature Reserve in Barnard Castle. The boggy ground on either side of the footpath was overgrown with butterburr leaves, meadowsweet, vetches, red campion and docks and was seething with insects and spiders.  These are a few that I managed to capture on camera. 

Earwig  - for more about earwigs click here

Female scorpionfly

Male scorpionfly - for more about scorpionflies click here

The beautifully iridescent green dock leaf beetle  - for more about this species click here

A sawfly that I haven't managed to ID for sure yet - for more sawflies click here 

A spider, Tetragnatha extensa, with a golden abdomen. For more spiders click here.

A very bug-eyed mayfly - possibly Ephemera danica. For more on mayflies click here.

A common green capsid bug Lygocoris pabulinus - for more on capsid bugs click here

A staphylinid beetle stretching its wings....

..... curling up its tail in characteristic defensive mode ....

..... and with its wings packed away, showing the extremely short wing cases. For more staphylinid beetles click here

Green Dock Leaf Beetles

I found scores of these green dock leaf beetles Gastrophysa viridula mating on dock leaves in the pastures beside the River Towy near Carmarthen earlier this week. The larvae chew holes on the dock leaves then pupate in the soil. In a good year they can produce three generations.

The beetles have beautifully iridescent exoskeletons which change from metallic green to bronze depending on the angle of the light. A single female can lay up to 1000 eggs. For the males, finding a female to mate with is highly competitive. In the top picture you can see two males confronting one another over a female.....

... and in this picture you can see a startling case of coitus interruptus, where a mating male - still coupled to the female - has been dragged off her by a rival. I thought this sort of thing only went on in the Bigg Market in Newcastle on a Friday night.....