Regeneration

At the end of August I was dismayed to find that my favourite (and most fruitful) piece of hedgerow had been thrashed deep into the trunks and down to ground level: all vegetation had been removed, leaving nothing but a mulch of dead plants and sawdust. I realise that all hedges need to be maintained, but August is simply the wrong time to do it: moth and butterfly caterpillars are still feeding and many sawflies are only starting their season in autumn. That's one of the reasons that it's illegal (in Ireland) to cut hedges between April and September (which I think is still too early).

I went back today to have a look, and was pleased to note that many plants had made a valiant attempt to produce some new growth and some species had even produced a few flowers. The fern growth particularly interested me, as the next few shots will show.

This is a brand-new frond of Lady Fern (notice that the growth is pale green and that there is no feeding damage, indicating that the growth is indeed fresh):

Lady Fern

I had one of those "turn it over" moments (I suspected what I was going to find) and confirmed that the frond was completely sterile: there were no spore-producing parts:

Lady Fern, showing absence of sori

It appears that the fern had realised that there was no time left to produce ripe spores, and instead of wasting energy on making sori, had simply made fronds without them. Why bother? Well, ferns are perennials: they produce new growth from the same base each year. The overwintering rootstock needs as much stored energy as possible, so it makes sense to throw out some new green growth in a desperate attempt to catch the last rays of sunlight before winter sets in.

Broad-buckler Fern was exactly the same:

Broad Buckler frond

Sterile Broad-buckler underside 

Hard Fern and Male Fern had also made a little new growth:

Hard Fern sterile frond

Male Fern

(I didn't check the Hard Fern frond for spores because very few of them are normally fertile. The fertile fronds have narrower pinnae than the sterile ones, they are more brown than green, and are much more upright.)

Many other perennials had made some new growth. Here's the gallery:

Barren Strawberry

Bramble

Bush Vetch

Cow Parsley

Common Dog Violet

Foxglove

Meadowsweet

Nettle

Raspberry

Germander Speedwell (and gall)

Willow (too late for the sawflies)

Herb Robert....

And its flower

It's great to see that a number of plants have made some kind of recovery, but it's sad that too many insects lost their opportunity on this stretch of hedgerow in 2011. On a more positive note, it is clear that plants are the basic resource for much of our wildlife: plants dictate which insects are to be found in a particular location. Although insects are beneficial in terms of pollination, plants seem to be a stabilising influence since they are more resilient in the face of damage.

If at first you don't succeed...

The Lissonota sp. ichneumonids have started to lay their eggs in unsuspecting moth larvae hidden inside grass seedheads. I've been following these for a week, now, and yesterday I was rewarded with a couple of shots of the egg-laying taking place:

Notice the antennae being used to pinpoint (ouch!) the location of the larva.


This shot shows the ovipositor at the moment it was being retracted. It's finer than a human hair.


This shot appears to be of a male (of a completely different species):

Staying with parasitic insects, these two Tachinids were on adjacent Bramble leaves. It looks as if they were pointedly ignoring each other. I see a great many Tachinids, and this shows just how many larvae of moths and butterflies are parasitised each year.

Some leaf-miners are very easily identified as such. This is Agromyza filipendulae, on Meadowsweet.


But the mines of Phyllonorycter species can easily be overlooked. This is Phyllonorycter rajella, on Alder. The pupa is only 2mm long, so the adult moth will never be recognised as such in flight.


That's the year half over, and it was only just new year.

I'm not sure if it's raining again or still raining.

Bombus pratorum is a bumblebee that I only started seeing locally about 3 years ago. It is thought to be becoming increasingly urbanised as farming practices push it out of agricultural land. It was certainly very numerous in central Glasgow when I visited last year.



Empid flies, or dance flies, have a wonderful long proboscis that they use to suck fluids out of the bodies of other insects.


Raspberry flowers have just opened, and the solitary B. pratorum was methodically working its way along the hedgerow, visiting every flower. If it accidentally revisited a flower it had already been to, the mistake was recognised in less than a second.


The Meadow Foxtail I showed last week has flowered.