High Heath

The Green-veined White butterfly has two generations per year. Unusually, the two generations are quite close, with some slight degree of overlap. Summer generation specimens are more strongly marked, with the black markings being darker and sharper than those of the spring generation.

 This pristine specimen is a female:

Female Green-veined White, summer generation

Given the lateness of the year, this is a rather early specimen for the second generation.

I have found the same, strange, earliness in the bumblebees this year. Queens emerged rather late, and nests were subsequently late, with workers not appearing until a few weeks ago. There is usually quite a delay until the new queens and males are ejected, but I have been seeing new queens and males for a couple of weeks now: much earlier than usual. It seems that some species are actually accelerating this year, despite the slow start, and are now ahead of normal schedule, rather than maintaining the 'lateness'.

Male bumblebees are ejected from the nest to fend for themselves, mainly because they do no work and would be an overhead on the nest. They are quite easy to identify, both in behaviour and appearance: they tend to crawl slowly over flowerheads in contrast with the workers which gather pollen almost frantically. They are also rounder, more colourful and have longer hair, giving them a 'fuzzy' appearance:

Male Bumblebee on Common Catsear

Any bumblebee with yellow hair on its face is likely to be a male, although not all males show this feature:

Male Bumblebee showing yellow hairs on the face

It isn't possible to identify these males to species without internal examination, but given the location, I'd go for Bombus lucorum s-s.

The hoverfly Helophilus pendulus is very numerous at the moment, with sightings on every excursion and location.

The hoverfly Helophilus pendulus

But I still examine every specimen, since I know that the much more local Helophilus hybridus can occasionally be found:

The hoverfly Helophilus hybridus

These rarely fly more than a few hundred metres from the boggy areas that contain Bulrush - the foodplant of their larvae. Identification relies on the differences between the markings on the abdomen. I might see only one or two of these each year.

The hoverfly Platycheirus scutatus was split into 4 species quite recently. Irish specimens appear to be the original Platycheirus scutatus s-s.

Platycheirus scutatus, female

Platycheirus scutatus, female

The larvae of these feed on aphids on low-growing vegetation.

Digger wasps can often be mistaken for hoverflies due to the oval yellow markings on the abdomen, the large head and the apparently short antennae: all features of hoverflies. These are predators on hoverflies, killing them and taking them back to the nest to feed their larvae:

Ectemnius continuus

Their appearance enables them to mix with hoverflies and approach them without disturbing them: I have often seen hoverflies and Ectemnius wasps feeding on the same flowerheads.

Hoverflies mimic the colour patterns of wasps and bees with greater or lesser accuracy. This enables them to inherit the protection that the colour patterns give to bees and wasps: birds know to avoid yellow and black -  nature's danger signal. So Ectemnius wasps are imitating hoverflies that are imitating wasps.

Staying with mimicry, Volucella bombylans is a hoverfly that mimics bumblebees (and lays its eggs in bumblebee nests):

The bumblebee-mimicking hoverfly Volucella bombylans

Volucella bombylans comes in at least three colour versions, each mimicking different bumblebees. I would dearly like to know if the different versions choose appropriate bumblebee hosts to rear their young.

Sawflies are very difficult to identify to species without a specimen, a microscope and a key. I have recently obtained a copy of the (55 year-old!) key and have identified this specimen as Tenthredo mesomelas:

The sawfly Tenthredo mesomelas

In an effort to understand these adults and larvae, I am participating in an online effort to gather together images of both adults and larvae of all sawfly species together for the first time.

When I was down taking photographs of orchids (see here), this micromoth flew over my head and landed on the Luzula upside-down, as so often happens.

The micromoth Glyphipterix thrassonella

The larvae of Glyphipterix thrassonella feed on Juncus rushes, which were in profusion. This is the first time I have seen this species since 2005.

Meadowsweet must be a very nutritious plant: there are many miners, micromoths and fungi which use it as a host. This is the fungal rust Triphragmium ulmariae, which is specific to Meadowsweet:

Triphragmium ulmariae on Meadowsweet

Note that the fungus has distorted the stem of the plant in order to maximise its surface area and therefore increase its chance of spore-dispersal.

And this is the mine of  Agromyza filipendulae on the same plant:

Unusually-shaped mine of Agromyza filipendulae on Meadowsweet

Note that this particular mine is atypical: it should have continued spreading to the left, but for some reason it has turned back at the fourth vein. Perhaps it was parasitised.