School Trips

This is the time of year when I take school groups out on walks to show them the delights of our countryside. I'm normally too busy doing identifications to get decent photographs, but I do manage to squeeze in a few.


This is the major season for hoverflies: hedgerows, verges, gardens and woodland are all buzzing with them as they carry out their vital pollination.

This is Cheilosia illustrata, which I only ever find - in small numbers - on Umbellifers (Hogweed in this instance) at the edge of woodland:

The hoverfly Cheilosia illustrata

The larvae of Cheilosia illustrata mine the lower stems of Hogweed.

The Syrphus family hoverflies are all very similar and can usually only be separated by examining microscopic characters.  This is Syrphus torvus, which can be identified by the hairy eyes:

The hoverfly Syrphus torvus (male)

The larvae of Syrphus torvus are aphid eaters.

New to me.

One of the great things about the internet is the way in which it connects people. As a result of online communications, I know that there has been a recent inwards migration of numerous butterflies, moths and other insects; Eupeodes corollae is one of them:

The hoverfly Eupeodes corollae

The larvae of Eupeodes corollae are also aphid eaters.


Soldier Flies are often mistaken for hoverflies, but the wing veins are distinctly different. There are a few metallic hoverflies, so the confusion is understandable.

Soldier Fly - Chloromyia formosa

This is a suitable place to show an Ectemnius wasp. Ectemnius wasps make solitary burrows for their larvae, which they feed exclusively on hoverflies. They have evolved to resemble hoverflies, presumably so that they can sneak up on them without causing them to fly off.

Ectemnius sp. wasp

Sometimes an opportunity arises to take a photograph which definitely fits more into the 'artistic' category: 

This Ichneumonid was closely examining the flowers of Bush Vetch in the hope of finding some larvae to parasitise. I saw this backlit shot as it was moving from flower to flower:

Ichneumonid on Bush Vetch

And now my new favourite photograph:

Ichneumonid parasitising moth larva in Cocksfoot grass

The female Ichneumonid has detected a moth larva inside the seedhead of Cocksfoot grass, and has swung her ovipositor round to inject an egg into the caterpillar. The egg will stay dormant inside the caterpillar until it pupates, at which time the egg will hatch and consume the contents of the cocoon. It takes a great deal of patience to get a shot like that. Each shot requires perhaps 30 minutes of watching the wasp moving from seedhead to seedhead and waiting for the moment of injection. These are my favourite photographs.

This has been a tricky year for Damselflies and Dragonflies: I have seen very few. A trip to a local pond solved that for me. This is The Blue-tailed Damselfly:

Blue-tailed Damselfly

And this is the Variable Damselfly - Coenagrion pulchellum, which is new to me:

Variable Damselfly

A tall, elegant grass has been bothering me for a couple of years, so I decided to identify it this year. It's Tufted Hair Grass - Deschampsia cespitosa - which forms tufts and has stems that reach up to my shoulders. I usually find it where I would normally see Damselflies, so they must need similar conditions.

Tufted Hair-grass Deschampsia cespitosa

New to me.

Bad light

Even when it isn't raining at the moment, any light that we do get is horrible, but we do what we can.

The Angelica is currently covered with insects of all kinds. Most are nectaring, but a few of them use the nectaring insects as a source of their own food in a similar way that crocodiles and lions use watering-holes as prime feeding ground.


The above shot shows:

A) Ichneumonids
B) Tenthredo sp. Sawfly
C) Ectemnius Wasp
D) Tree Wasp

This nectaring Ichneumonid poses a bit of a problem. I've seen this upward-curved ovipositor a few times, but I can't really work out the purpose of that curve. Maybe it reverses into a hole and lays its egg backwards?


Sometimes you see something and you intuitively know it's new. This Leafhopper was a bit larger than the usual ones and slightly more rounded. A quick check through the references reveals that it's Aphrophora alni, and is new to me.


Similarly, this hoverfly shouted "I'm new, too", and I managed to get a few shots before it flew off. It's certainly a Melangyna sp., but that's as close as we can get without capturing it.


These are scarce at the best of times: the larvae are specialist eaters of specific aphids.

A new Hedgerow

And a fine one. A long country lane running east-west with pasture on both sides, flanked by Ash, Hawthorn and Elder. The verges have been allowed to flourish unhindered and I saw many new species and a few old friends.


First, a new species to me, and a very scarce one. The Hogweed leaf-mining Phytomyza heracleana. A few Irish records.



The Parsnip Moth eats the flowers of Hogweed and other umbellifers. Once a group of florets has been consumed, they march off to find another unoccupied one. This one was about to be repelled by the inhabitant of the umbel to the top left (notice the hidden larva, level with its head, to the left.)


A hoverfly that I see very rarely, and photograph even more rarely: Cheilosia illustrata.


An Ectemnius sp. wasp. This one was nectaring, but the whole family are hoverfly-killers. Notice the hinged antennae that can be raised to cover the face. In the upper position the antennae give the face a yellow centre, like many hoverflies. The antennae also look much smaller in that configuration, and appear to emerge from the top of the head, just like a hoverfly. This allows the wasp to approach hoverflies without scaring them off. Reverse mimicry in action.


Earlier in the week I showed a female Ghost moth that came to light. This is the male. These are supposed to smell of goat, so I didn't bother sniffing it.


An as yet unidentified leafhopper. Work ongoing:

A fine hedge, and one that I'll return to soon.

Other parasites and predators

The last couple of posts were about Ichneumonids, which are parasites on the larvae of other insects. This Tachinid Fly is another:


Tachinids are fairly easy to identify: they have very long spines all over their body. Their flying habit is also easily recognisable, once identified: they fly low and slow over vegetation, looking for their hosts, and dart under leaves very suddenly, just like Ichneumonids. Tachinids are ectoparasites: they lay their (multiple) eggs on the outside of the host larvae. The Tachinid larvae then hatch out and eat the host while it is still alive. This can result in a very messy corpse indeed.

Moving on from parasites, we come to predators. Everyone knows about mimicry, where a harmless insect, such as a hoverfly, can have black and yellow bands just like a wasp. This similarity affords the hoverfly protection from predators such as birds, which avoid eating insects that might be unpleasant or harmful. In the following case, however, we have the reverse situation. This is an Ectemnius sp. wasp:



A few points are worth noting:

1) the body is black and yellow, as you might expect from a wasp, but the yellow bands are very rounded.

2) the head is very large, giving the impression of large eyes.

3) the antennae are bi-coloured, hinge in the middle, and can be pulled up into notches in the 'face', leaving a yellow area in the middle of the face.

Has this rung any bells yet?

Going back to the points above:

1) the yellow bands on hoverflies can be rounded.

2) hoverflies have large eyes

3) hoverflies have short antennae that sprout from the top of the head, and often have a yellow face.

So the inescapable conclusion is that this is a wasp which is trying very hard to look like a hoverfly.

Why?.....because it is predatory only on hoverflies, which it catches and then feeds to its young. It resembles a hoverfly so that it can sneak up on them and catch them unawares.


So here we have a wasp that is pretending to look like a hoverfly that is pretending to look like a wasp. Talk about a wolf in sheep's clothing...