The Potter Wasp Odynerus spinipes is an impressive creature. A long abdomen with yellow lined abdominal plates all of an equal size save for the second which is enlarged to show an expanse of black.  The rest of her body is predominantly black, with yellow flashes on her legs and face.

In early Summer she finds a promising patch of clay cliffs and picks her nesting spot. Instead of merely digging a hole and laying an egg in the bottom like other wasps, she does something far more creative. After digging a burrow, she will begin to collect soft clay from a puddle before slowly constructing a chimney. About 3cm high and curled over at the top to prevent rain from entering, the chimney is now complete. A nest cell is now formed at the bottom of her burrow and an egg is laid, attached to the cell wall by a fine thread.

Female Odynerus spinipes carrying a weevil into her chimney nest

Female Odynerus spinipes carrying a weevil into her chimney nest

Construction complete, she now has to provide food for her larva when it hatches. The larva has very specific tastes and the adult wasp has to know exactly where to find the food to satisfy this fussy little eater. The larva will eat only the grub of a specific weevil species, Hypera plantaginis. which lives on Bird’s-foot Trefoil. The wasp can be seen darting forward and back across this habitat using her eyes and chemoreceptors in her antenna to locate her prey. Whenever she finds one she stings it to paralyse it before clutching the grub to her chest and flying back to her nest. She paralyses rather than kills it, keeping it alive to ensure that it does not rot. She drops the grub on top of the egg cell for her larva to eat when it emerges. She will provision her nest with up to 30 weevil grubs before deciding that her larva will have enough to eat.

There is, however, one more thing the mother Odynerus spinipes has to deal with: the threat of a parasitoid wasp. Jewel like in her appearance, the villain in question is a beautiful creature. Her name is Chrysis viridula, and she is specifically adapted to target Odynerus spinipes. She will spend her time zipping back and forth along the clay banks searching for a chimney she can use.

The beautiful Chrysis viridula searching for Odynerus spinipes nests on clay cliffs.

The beautiful Chrysis viridula searching for Odynerus spinipes nests on clay cliffs.

Once she has found one she will tentatively patter about the entrance to the hole, attempting to determine whether the occupant is home or not.

If she is surprised by the home’s occupant she is well equipped should the owner attack. Her beautiful exoskeleton is also extremely thick and hard, protecting her from stings. If it all gets too much and the ferocity of the attack is too hard to bear she has another, quite endearing trick. As the underside of her abdomen is concave she can curl herself up into a tiny ball, protecting herself from the onslaught by the home’s occupant.
If she remains undetected however, she will reverse into the wasp’s home and lay her eggs right beside the wasp’s eggs. Her eggs hatch first and will proceed to eat the host’s eggs. This all goes undetected by the O. spinipes and she will seal up her nest hole for the winter just as she would normally, unaware of the ‘cuckoo’ that has infiltrated her nest.

Chrysis viridula emerging sheepishly from a chimney of an Odynerus spinipes

Chrysis viridula emerging sheepishly from a chimney of an Odynerus spinipes

Stylops Flies

Sneaky, underhand and generally distasteful: Stylops flies do not lead fulfilling lives. Small and black with membraneless wings, males are the only ones blessed with flight. The females are condemned to a life as little more than a reproductive tract with a mouth. They are obligatory endoparasites that live in the abdomens of solitary bees such as Andrena scotica, the chocolate mining bee. Other species inhabit other insects such as grasshoppers and dragonflies.

Female Andrena scotica solitary bee with three Stylops fly larva in its abdomen. (Two female larva on the left, one male on the right)

Female Andrena scotica solitary bee with three Stylops fly larva in its abdomen. (Two female larva on the left, one male on the right)

While males begin life in the abdomen along with the female, they soon emerge. The males now fly around to find other bees which have been stylopised. Once found they will land on the bee and proceed to stab their adaegus (penis) in to the reproductive tract of the female, through her exoskeleton. This brutal technique is known as traumatic insemination and will eventually kill the female from excessive damage or disease. However, before this happens the bee will land on a flower and the female stylops will lay hundreds of eggs into the flower. The eggs will mix with the pollen and the next time a bee visits the flower it will take up the eggs too. The eggs will eventually hatch, worm their way into the bee’s abdomen and start the cycle again.

Bee-flies

The lovely and fluffy Bee-fly (Bombylius spp) buzzing about full of energy, hovering interestedly in front of your face as you walk through a meadow. Soft hums intonated with tiny high pitched vocalisations, seemingly of curiosity. The bee-fly is a lovely animal. He uses his long tongue to sip nectar from flowers and is an incredibly adept flier, hovering statically or moving with huge speed. When he spots a female he will fly to heights of up to 2.5m and chase off all neighboring males. Once finished fighting off intruders he will spin enthusiastically at the female to woo her. Unfortunately, however, her life is a less friendly one. The female bee-fly will buzz along searching for a mining bee’s burrow. When she finds one she will rapidly twist her body and flick an egg, with great accuracy, right into the burrow while hovering! The egg rolls deep into the burrow where, when it hatches, the grub will crawl towards the host’s larva and wait for them to grow to almost full size before striking. At last, it will latch on to the bee’s larva and suck out its bodily fluids, eventually killing it. The bee-fly’s larva will now pupate and fly innocently out of the burrow.

Male Bombylius canescens in flight

Male Bombylius canescens in flight

Bombylius canescens female flicking eggs into the burrow of a Halictid bee species

Bombylius canescens female flicking eggs into the burrow of a Halictid bee species

Himacerus mirmicoides ant mimic.

The nymph of the Damsel Bug Himacerus mirmicoides lives in short vegetation dotted throughout along the ground. Lots of things will want to eat this little nymph and so he has a few tricks up his six tiny sleeves. With skinny waists between each of his body segments and a shiny black colouration this little nymph is a wonderful ant mimic. He uses this as a form of defence as birds will rarely pick off ants and so he sits quietly on a flower watching the world go by, hoping he won’t be recognised. However, this seemingly innocent little bug has another reason for looking like an ant – food. By being camouflaged, he can sneak along routes used by the ants and surreptitiously snaffle his favourite food source while the ants aren’t looking – aphids. He uses his long sharp and slightly curved mouthparts to suck out the aphid’s juices from the small green creatures.

Himacerus mirmicoides nymph mimicking an ant on an Asteracea flower

Himacerus mirmicoides nymph mimicking an ant on an Asteracea flower