Digger wasps

Late in summer, perfect little round holes with small mounds of spoil around them start appearing throughout the garden. These are the burrows of the digger wasps. The adult wasps work tirelessly to excavate tunnels and underground chambers. They dive into the hole head first and emerge a few minutes later with a little bundle of earth that they carefully move out of the way of the tunnel entrance.

The wasp grubs will over-winter deep down in the tunnels, feeding on a larder of food the adult wasps provide for them. Then late next summer, new wasps will emerge and the cycle starts all over again.

A digger wasp clearing the spoil from her tunnel
A digger wasp clearing the spoil from her tunnel
A digger wasp diving back into her tunnel
A digger wasp (Mellinus arvensis – the field digger wasp) diving back into her tunnel

These solitary wasps are not aggressive and I’ve never known of one stinging a human. They do have a sting, but they only use it for paralysing their prey – mostly flies.

It’s a bit sad that when you look for information on the internet about garden insects many of the results will be about “control” methods: and that’s the case with digger wasps too. Yes, they do make holes and little mounds of earth, but they do no damage to your grass or plants. There is certainly no need to “control” them: you might even be grateful to them for eating up some of your houseflies:)

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Aristolochia baetica / birthwort flowers

Aristolochia baetica flowers. This species of Aristolochia is native to southern Portugal, Spain and north Africa.
Aristolochia baetica flowers. This species of Aristolochia is native to southern Portugal, Spain and north Africa.

Aristolochia plants have been used for centuries in traditional medicine. However, their active component – aristolochic acid – is known to be carcinogenic and several studies have linked use of the plant in herbal medicines with cancer.

Aristolochias are sometimes known as birthwort and/or Dutchman’s pipe vines.

The large-leaved Dutchman’s pipe vine (Aristolochia macrophylla) is often grown as a low-maintenance climber and is a useful (but deciduous) plant to use for screening in planting schemes.

Feeding garden birds: a £400m quandary

Through my window I can see: blue tits, chaffinches, great tits, dunnocks, sparrows, blackbirds, starlings, collared doves, jackdaws, magpies, an occasional woodpecker… and the list goes on.

The resident pair of collared doves - always on the look out for food
The resident pair of collared doves – always on the look out for food

For many of us, garden birds are an intrinsic part of our gardens. They bring life, motion, song and colour right to our doorstep. But how much do they rely on us to feed them?

These days we are exhorted to feed garden birds and the calls come from many directions: charities like the RSPB; garden centres; daily newspapers; TV programmes. And we’re told not only to feed the birds, but to feed them with bespoke feed, and to feed them every day of the year. Mmm, what’s going on here?

When I was growing up, we often fed the birds old bread, cheese and bacon rinds. We didn’t feed them mouldy bread or cheese, just old dry stuff. Sometimes, particularly around Christmas time, we’d make a special treat cake for the birds out of lard or dripping and dried fruits, oats and more stale bread. But oftentimes we wouldn’t feed the birds: if there were no left overs the birds weren’t fed. There were plenty of birds around and I never gave very much thought to feeding them: it was just an ad hoc thing.

Nowadays though, feeding garden birds is big business. It’s hard to find a definite value for the industry. An FAO report in 2010 said that the UK is “one of the leading countries in outdoor feeding” and a survey found that four out of five gardeners over 65 years of age feed garden birds. In an article in 2012, Germaine Greer dug deep into the economics of wild bird food and noted that the market in the UK alone was worth around £400m. The same FAO report mentioned above said that in the United States $2.7bn dollars per year was spent on food for wild birds, with a further $800m on accessories. Whichever way you look at it, feeding our feathered friends has become big business. Why is that?

In part, it could be to do with the erosion of “natural” habitats for our wild birds: as more and more houses, industrial sites and infrastructure projects are built, places for birds to feed “naturally” grow scarcer. Coupled with that, changes in farming practices including cropping patterns, pesticide use, loss of hedgerows and field margins mean that “natural” food sources for wild birds are reducing in the countryside that remains. The potential for gardens to compensate for these reductions is significant. But is feeding the birds, with mixes of imported seeds at exorbitant prices, the way to go?

I don’t know. I find it a bit of a quandary, but I’m inclined to think it’s not.

For most of my life I have carried on with my haphazard attitude to feeding birds. I’ll always feed them if it’s very cold and always make sure there’s clean water available for them.

However, for much of the last year I have been feeding the birds, primarily because of old Hoppity robin who came to stay. He would sit near the back door waiting for food and so I fed him. If the food was late, he’d move closer and closer to the back door: guilt and sympathy kept me feeding him. And by feeding him, I was also feeding lots and lots of other birds.

Hoppity robin shortly before he disappeared: after his moult he looked a bit worn around the edges, maybe he had just grown too old to carry on
Hoppity robin shortly before he disappeared: after his moult he looked a bit worn around the edges, maybe he had just grown too old to carry on

But at the back end of September Hoppity disappeared. For a few days another robin had also been singing in the garden and the last I saw of Hoppity was the two birds fighting with each other. However Hoppity, having only one leg, was clearly no match for the newcomer two-legged robin. Next day, there was no more Hoppity robin, and although I’ve watched out for him, I haven’t seen him since.

So now, there’s less of a specific reason to feed the birds and I’m thinking about it more and am feeding them less.

In addition to the questionable economics and environmental ethics (where and how are the seeds and peanuts grown?) of the wild bird food industry, feeding birds frequently and routinely also raises issues relating to bird health and disease transmission. But that’s another topic for another day.

Flying ants

Today was the first day for a mass emergence of flying ants: that’s about three weeks later than it ‘usually’ happens here.

As the winged ants emerge, they climb up anything they can find to get as high as possible before taking to the air.
As the winged ants emerge, they climb up anything they can find to get as high as possible before taking to the air.

For a couple of weeks, the smaller male winged ants have been creeping out of cracks and crevices, only to be dragged back in by the regular worker ants. Today, the time was right and the boys got their freedom.

You can see the size difference here between the big females (new queens) and considerably smaller, but very keen, males.
You can see the size difference here between the big females (new queens) and considerably smaller, but very keen, males.

The ants are ‘supposed’ to mate in the air, but they’re quite happy to do it anywhere…

Ants mating on a sun chair
Ants mating on a sun chair – the little male is round the back.

Once mated, the new queen sheds her wings and scurries around looking for a new place to start her own colony.

Newly mated queen ant without her wings.
Newly mated queen ant without her wings.
Flying ants caught in spider's web
Flying ants caught in a spider’s web

Happily, thanks to the birds and the spiders, not all the flying ants make it to start new colonies.

The Society of Biology have an interesting pdf factsheet about flying ants available to download here.

 

 

Butterfly eggs

These are the eggs of the large white (the clump of yellowish eggs) and small white (the single whitish eggs to the left and right) butterflies. Both butterflies are known as cabbage whites.

These eggs have been laid on nasturtium leaves: they prefer cabbages and other brassicas, but nasturtiums are a firm favourite food plant of the cabbage whites too.

Eggs of the large white (Pieris brassicae) and small white (Pieris rapae) butterflies. And a tiny newly hatched large white caterpillar.
Eggs of the large white (Pieris brassicae) and small white (Pieris rapae) butterflies. And a tiny newly hatched large white caterpillar.

I gave up growing cabbages in the garden because controlling the caterpillars of these two species of white butterflies on them was impossible. Well, impossible without chemicals. And I took the decision that gardening at home, for me, is gardening for  fun and pleasure; it’s not about necessity or earning an income. So, if things won’t grow successfully without plant protection products, I don’t grow them.  It’s a very different story when you’re growing a crop to feed your family or earn an income: choices are much harder then.

The photo below was taken about a fortnight later: the caterpillars are literally eating themselves out of house and home!

Caterpillars of the large white butterfly decimating a nasturtium
Caterpillars of the large white butterfly decimating a nasturtium

Plants for butterflies: hemp agrimony

Hemp agrimony (Eupatorium cannabinum) is one of the very best plants for attracting butterflies: even better than buddleia. Despite its name, it has nothing at all to do with cannabis or hemp.

Hemp agrimony flowers with red admiral and peacock butterflies.
Hemp agrimony flowers with red admiral and peacock butterflies.

Hemp agrimony is a hardy perennial that is native to the UK. Although seldom grown as a garden plant, it is certainly worth considering if you are planning a wildlife area in your garden.  It prefers soils that are moist a good deal of the time and quite a sunny position. Although it can be grown from seed, it is simpler and more reliable to divide a clump if you know somebody who has some they can share with you.

The flowers, a frothy mass of pale pinky-mauve appear in July and August – just in time for many butterflies. The dried flowers and leaves of hemp agrimony are sometimes used as an infusion which has a mildly cleansing and toning effect.

Sawfly larvae on birch

These sawfly larvae are making short work of devouring the leaves on this birch sapling.
These sawfly larvae are making short work of devouring the leaves on this birch sapling.
I think these are the larvae of Croesus latipes - I can't find a common name for them. They are considered a minor nuisance, not a serious pest.
I think these are the larvae of Croesus latipes – I can’t find a common name for them. They are considered a minor nuisance, not a serious pest.

The posture the larvae are adopting is characteristic of many sawfly larvae. Also note the way their stubby little prolegs start from segment five (the first three pairs of legs are the proper legs that will remain in the adult, they are on segments one, two and three).

Generally, caterpillars of moths and butterflies have fewer prolegs than sawfly larvae and they start further back than segment five. Have a look at the post about caterpillars on redcurrants for a labelled photo showing the segments, legs and prolegs.