On the 30th May 2008 during a trip to Windmill Farm on the Lizard peninsula I did my usual circuit of all the dragonfly hotspots within the reserve, including the bunded northern scrapes. These bunds may not be the most attractive of features to have around a pool but they are a clever use of the material which had been excavated in order to create the pools in the first place, in that they make an effective windbreak around the entire water body.
This helps protect emerging dragons from the worst of the wind at a time when they are at there most vulnerable. It also provides an attractive substrate for insects that having burrowing larvae, chief amongst them being the Green Tiger Beetle – Cicindela campestris, numerous fearsome adults of which can frequently be found hunting around the bare pool margins throughout the summer months.
As I approached the pools on this particular occasion I could hear the familiar rustle that usually signalled a clash of dragonfly wings during a heated dispute between males. However if that was the case I couldn’t actually see any signs of aerial combat even though it seemed to be coming from close by. I glanced down to a patch of bare clay material and there was a male Four Spot Chaser - Libellula quadrimaculata frantically beating it’s wings seemingly unable to fly. As I looked more closely I initially thought that this unfortunate dragonfly had been bitten in half by a bird and had subsequently dropped to the ground as a result, mainly because I couldn’t see the majority of it’s abdomen.
However on closer examination, and much to my amazement , I realised that this Four Spot Chaser was in fact being dragged down the burrow of a Green Tiger Beetle larva!
It seemed that the Green Tiger Beetle larva could easily pull the dragonfly down into it’s lair to the point where pretty much all of the abdomen was below ground, but at that point the dragons thorax was too big to fit in the hole. With the larva temporarily at an impasse the dragonfly would then frantically buzz it’s wings in an effort to extract himself, lifting the first few segments of his abdomen perhaps 1cm or so out of the ground, desperately clinging to any nearby blades of vegetation which swiftly buckled under the strain .
This titanic struggle continued with each protagonist temporarily gaining an advantage in the tug of war before the other regained lost ground. I took the opportunity of photographing the dragonflies struggle before grasping him by the thorax and pulling him free. The Four Spot Chaser promptly celebrated his freedom by giving me a little nip and flying off before I had a chance to examine the tip of his abdomen, seemingly unaffected by the ordeal.
The larvae of the Green Tiger Beetle do not seem to leave their burrow but instead position their head and jaws at the mouth of the hole. There they remain, flush with the entrance, awaiting the arrival of an unsuspecting insect which is dispatched in an instant. That a medium sized dragonfly would fit into that scenario seems unlikely as they do not walk along the ground, however this particular Four Spot Chaser obviously chose the wrong spot to land on!