Friends of Heene Cemetery

We continue to be startled at the diversity that our species surveys are uncovering. Who knew that Heene Cemetery’s small, one-acre, town-centre site would be so species-rich? We have already detailed this in a series of blog posts about the mosses, crickets and grass-hoppers, hoverflies, trees and bees that we’ve found here. It’s now the turn of wasps, whose diversity could eventually surpass that of everything else combined. Why might this be?

The fossil record shows that wasps came before both bees and ants. Wasps gave rise to bees that no longer hunt, and then to ants that no longer have wings. Being first, evolutionarily, therefore, results in greater variety. The numbers associated with this are staggering, with current and estimated species totals looking like this:

	Worldwide species	Species in Britain
Wasps	100,000	9,000
Bees	22,000	270
Ants	12,000	51

Some authorities believe that there might even be 160,000 species of parasitoid wasp worldwide, but this will have to remain conjecture.

Social wasps

Everyone knows that ‘a wasp is a wasp’. It’s called the Common Wasp, and it’s found throughout Britain:

Common Wasp (Vespula vulgaris), Heene Cemetery, August 2020

Everyone knows, sometimes to their cost, that these insects can give a painful sting. They are the bane of picnickers. (Were Italian Vespa scooters so named because of the annoying noise they make? As you can see above, the word ‘vespa’ in Italian means ‘wasp’.)

Female workers with their yellow and black stripes only live a matter of weeks, but the larger, mated queen will hibernate underground, laying her eggs in the summer. Adults feed mostly on nectar, but other sugary food will be taken if available (jam included). They will also look for proteins (in the form of other insects and invertebrates) which are returned to the nest to support the larvae. Spherical wasp nests can contain between 5 and 10 thousand individuals.

These social wasps eat aphids and caterpillars and are therefore insect-controlling predators. Some of them are also pollinators, which is a bye-product of their search for nectar, which sustains them as they look for proteins. All wasps are predatory, whereas only some bees are.

Things get interesting when we consider other social wasps. There are up to 15 species of social wasps in Britain (including the hornet). The smaller ones are hard to tell apart, but here is the German Wasp:

German Wasp (Vespula germanica), Heene Cemetery, July 2023

This wasp is, to all intents and purposes, identical to the Common Wasp, apart from minor colour markings.

For the moment, we’ve not knowingly seen any of the other social wasp species.

Solitary wasps

Solitary wasp species outnumber the social species by a substantial margin, but these are proving to be very difficult to spot and then identify. Our success in this has been limited, but has resulted in the following individuals:

Sand wasp – unnamed 1 (Ectemnius sp.), Heene Cemetery, July 2023

The individual above is a sand wasp, a predator (usually) of flies. Each species hunts for a specific type of fly, which they paralyse and take into their underground nest burrow. Flies thus captured become a living food source for the wasp’s developing larvae. These wasps often become the target of other parasitic wasps and flies, and sometimes the hunted sand wasp will prey on its own parasites.

Potter wasp (Ancistrocerus sp.), Heene Cemetery, August 2023

The potter wasp above is also a predatory wasp with a wide variety of prey that includes beetle larvae, spiders and caterpillars. As with the sand wasp above, they also paralyse their prey, placing them live in a nest cell for their developing larvae. Their nests range from existing cavities and holes (including old screw holes) which they repurpose as single nest cells. Sometimes they make elaborate mud nests or ones that they make from chewed plant material. In some cases, these nests resemble miniature pottery, hence the family name.

Gall wasps

There is another group of wasps, the gall wasps, that we may never see but which we nevertheless know about. These tiny wasps lay eggs in the tissue of leaves and as they develop they create a deformity in the leaf surface that we know as ‘galls’. Each species of gall wasps is a specialist of a particular tree from which their name is derived, and each gall has its own appearance. We can therefore add some of these wasps to our database, even though we may never see the insect itself. Galls that we have seen are:

Knopper Oak Gall Wasp (Andricus quercuscalicis), Heene Cemetery, August 2020

Ram’s-horn Gall Wasp (Andricus aries), Heene Cemetery, September 2022

Smooth Pea Gall Wasp (Diplolepis sp.), Heene Cemetery, August 2022

Spangle Gall Wasp (Neuroterus quercusbaccarum), Heene Cemetery, August 2022

Parasitoid wasps

The next group of wasps is perhaps the most interesting and diverse. They may also be ones that most readers have never heard of. These are the ichneumon wasps, braconid wasps and spider-hunting wasps. These are solitary wasps that are key predators, usually of caterpillars, butterflies and moths. They are also visually distinct from the other types of wasps shown above. Worldwide, there are thought to be more ichneumon wasp species than bird and mammal species combined.

Ichneumon wasps are slender, long insects with long antennae – and the characteristic ‘wasp waist’ that is shared by all wasps. British ones range in size from one to five centimetres in length. These creatures can sting – and will use this to paralyse their prey – although British ones are generally incapable of stinging people. Females have a long ‘ovipositor’ with which they lay eggs, often into the living body of their prey (along with venom and a virus, the latter helping suppress the victim’s immune system from attacking the parasitic larvae from developing). There are an astonishing 2,500 different ichneumon wasps in Britain alone, and a further 1,300 different braconid wasps. As a general rule, every species of caterpillar, fly and beetle will have at least one parasitoid wasp that exploits it.

The ones that we have seen in the cemetery have been hunting low down in vegetation, their antennae waving from side to side as they sniff the air to locate suitable prey. (It is worth noting that parasitoid wasps have been trained to sniff out drugs, dead bodies and explosives, showing them to be as capable as sniffer dogs.) They also consume nectar from flowers, and are rarely accidental pollinators. Their value in broad terms is that they control insect parasites that would otherwise attack flowers, vegetables and crops.

Here are five that we have been able to identify down to species level. Although they have a Latin name (because we know the species), they have no common English name. Here they are, just three (so far):

Ichneumon wasp – unnamed 1 (Ephialtes manifestator), Heene Cemetery, August 2020

Ichneumon wasp – unnamed 2 (Diplazon laetatorius), Heene Cemetery, June 2022

Ichneumon wasp – unnamed 3 (Hepiopelmus variegatorius), Heene Cemetery, August 2023

Another photograph of Hepiopelmus variegatorius, Heene Cemetery, August 2023

Unknown ichneumon wasp (possible Amblyteles armatorius), Heene Cemetery, July 2022

Ichneumon wasp – unnamed 6 Amblyteles armatorius, Heene Cemetery, July 2022

There is a further wasp, closely resembling the ichneumons, but which is a spider hunter. These individual species each have their chosen spider prey. As spiders themselves do with their own captives, these wasps merely paralyse their captive spiders before dragging the victim into their nest so that their larvae have living bodies from which they can gain nourishment.

Spider-hunting wasp – unnamed 1 (Auplopus carbonarius), Heene Cemetery, August 2023

The unidentified ichneumon wasps

Beyond this, we have seen a number of other ichneumon wasps, although these have been impossible to identify, and therefore have not been added to our database. Here are their photographs. All are different from each other: