Category: Insects

Oak Apple

oak apple

Oak apples are at their freshest – spongy and sometimes rose-pink – around the time of Oak Apple Day, the 29 May. The day commemorates the Restoration of the Monarchy in Britain on 26 May 1660, when Charles II returned from exile.

The summer generation of the gall wasp Biorhiza pallida, has already emerged. As many as thirty of them live in separate larval chambers in the gall but they’re often joined by parasites and by inquilines: live-in lodgers that don’t attack the resident larvae. The variety of species sharing the gall probably explains the different sizes of the exit holes that they’ve made.

The fertilised females will go on to penetrate the ground and lay their eggs in the roots of oak trees. The larvae usually spend two winters developing underground, each in its own root gall, then emerge early in the year. This early spring generation will all be wingless and all female.

The unfertilised females climb into the branches of the oak and lay numerous eggs at the base of a bud. An oak apple forms from each bud and, as in my photograph, often several of them are clustered together. Males and females develop in separate galls.

These were on a small sessile oak growing by the towpath alongside the Calder & Hebble Navigation, downstream from Horbury Bridge.

Artichoke Gall

artichoke gall

These artichoke galls began to form earlier this summer when a female gall wasp Andricus fecundator laid a single egg in each of the terminal buds of this branch of a sessile oak.

Artichoke galls are also known as larch-cone galls or hop galls. The larva develops protected by the overlapping scales.

An adult female will emerge in the spring to lay her unfertilised eggs in the emerging catkins of the oak. The alternate summer generation of male and female gall wasps will emerge from the resulting hairy catkins galls in May or June.

This sessile oak was growing on the embankment of the disused colliery railway which formerly connected Hartley Bank to Addingford, crossing the canal and river en route.

Patio Patrol

In close-up, this paved area at the end of Barbara’s brother’s South Ossett garden is a miniature landscape; a sun-baked plateau dissected by a network of canyons. Brown ants patrol the edges of a dense forest of mosses.

Moss is still green in the crevices but on the surface of the concrete paving slabs, it’s dried up. White whiskers give the clump a little protection from the direct glare of the sun.

Spore capsules of the mosses are like pepper-pots on wiry stalks. One (left) has split open, leaving the teeth around the rim splayed out, like the petals of a miniature daisy.

Spots, Stains and Splatters: Crustose Lichens

There are a few spots of a dirty yellow crustose lichen on the concrete. It’s dotted with orange sporangia, each with a narrow yellow rim.

This black crustose lichen looks like little more than a tar stain on the concrete but my macro photograph reveals a surface cracked like dried mud.

A white lichen looks like splatters of paint. In close-up almost every individual scale in the colony is dotted with a small depression, perhaps the lichen’s spore-producing body.

I’m guessing that the single orange sporangium is a different species of lichen – probably the yellowish species – that has become engulfed by the white one.

Bluebottles and Bumblebees

When I drew these a month ago on 11 June the temperature was climbing to 34°C, 92°F, in this sunny corner, so insects were active. A half-size version of a bluebottle touched down while a small marmalade-coloured bumblebee visited the white clover at the edge of the lawn.

I was soon adopted as an extension of the habitat by a small brown spider which climbed over me.

Flying Ants

This afternoon, for the first time in a week or more, the sky is overcast. It’s so grey over to the east that you could believe that we might get a rain shower; we don’t, but these still, sultry conditions are perfect for the brown ants that have a colony under our patio to release their winged queens and males. Hundreds of them are lined up ready to take off over the lawn as the ground crew, the colony’s workers, scurry about excitedly.

It seems that some of the queens don’t go far on their nuptial flights. A few hours later, as I’m watering a small patch of the lawn that I’ve reseeded, I spot three or four of them running around and, when one of them finds a likely cavity, it heads straight down; the start of a new colony, if all goes well.

The queen ants are so much larger and plumper than the workers, with glistening abdomens, so that when I first see them I think that they’re some kind of ground beetle. They’ve already discarded their wings, which are used solely for the nuptial flight.

Vapourer Moth Caterpillar

The four cream ‘shaving brushes’ on the back of the Vapourer moth caterpillar, Orgyia antiqua, make it easy to identify and presumably make predators think twice about trying to eat it.
This was nibbling away with three or four vapourer caterpillars on willow leaves by the woodland ride at Thorpe Marsh nature reserve. Larger numbers of vapourers can have a devastating effect on city trees.

Wasp Beetle

The wasp beetle, Clytus arietis, does a good job of mimicking a hunting wasp but is harmless. Its larvae live in deciduous timber.

This one was taking a break on a dog daisy growing at the edge of a woodland ride, once a railway, on the Yorkshire Wildlife Trust’s Thorpe Marsh nature reserve, near Doncaster.

Link

Thorpe Marsh YWT reserve

Veg Patch Insects

12.30 pm, 23°C, 71°F: On a visit to the RHS gardens at Harlow Carr, Harrogate, I spend half an hour drawing some of the insects that are visiting the vegetable patch.

At first,  it’s the fly, a house fly or one of its close relatives, basking in the sun on the arm of the garden chair that attracts my attention but apart from going through a grooming routine, as flies habitually do, it’s isn’t engaged in any interesting behaviour.

A drone fly visits a yellow tagetes flower, as does a small white butterfly.

Bee on Sweet Pea

A black bee on a sweet pea flower bends its abdomen upwards, takes the stamen between its back legs and transfers its white pollen  to the underside of its abdomen. It appears to be sipping nectar simultaneously.

Black Hunting Wasp

Those white dots might have been a little further along the antennae.

Moving flower pots under the bench in the greenhouse, I came across a black hunting wasp* with conspicuous white dots halfway along its antennae. There also appeared to be a white dot at the rear of its thorax. It’s been a mild day and it was even warmer in the greenhouse, even so I was surprised by how active it was. It didn’t appear to be just running for cover after I’d removed the plant pots, it appeared to be actively hunting on the surface of the damp soil. Its antennae were exploring all the time, moving independently of each other.

It was a little over a centimetre, about half an inch long, perhaps a little longer including the long antennae.

* It’s an Ichneumon – a relative of bees, wasps and ants – Ichneumon suspiciosus, a common species throughout the British Isles. Seeing it from above, I’d noticed a brownish tinge on its wings which was, in fact a broad red or orange band on its abdomen. The species also has pale spots to the rear, which I didn’t notice as it scuttled along.

Harlequin Ladybird

harlequin ladybirdThis harlequin ladybird landed on the window this afternoon. It’s probably on the look-out for a suitable site to hibernate.

A map on the Harlequin Ladybird Survey website shows how this North American species, introduced to Europe in 1988, has spread from the south-east of England. From a couple of records in Yorkshire in 2003-2004, it has now been recorded across most of the county, with the exception of parts of the Dales, the North Yorks Moors and the Wolds. It’s apparent absence here may be the result of there being fewer people to record them.

Link: Harlequin Ladybird Survey

Knopper Galls

Knopper galls

Hundreds of knopper galls are scattered beneath the oaks in Nostell Park. On some you can see the way that the acorn has been transformed into the home and the food source for the larva of the gall wasp Andricus quercuscalis. The acorns have stalks, botanically penduncles, so these are the acorns of the common or pendunculate oak, Quercus robur.

It’s the asexual generation of this gall wasp that produces the knopper gall; the alternate sexual generation produces tiny galls on the male catkins of the Turkey oak, Quercus cerris. Turkey oak acorns have ‘mossy’ cups, that remind me of the furry Russian hat that Ivan the Terrible might have worn. There are several Turkey oaks at Nostell.

Bracket fungus

This species of bracket fungus is sprouting on deciduous stumps in the woods around the lakes.

Rabbit Mesh

Lettuce
Additional security around the lettuce bed.

The head gardener is adding wire mesh to the newly restored iron gate to the walled garden.

“Is that to stop the ducks getting in?” (It’s been a good year for the mallards on the nearby lakes).

“No, rabbits.”

“I worked on the film of Watership Down, so I’m always rooting for the rabbits.”

“There’s plenty of grass out there!”