The hundreds of galls in Herefordshire's old trees

This doesn’t mean that there is less to appreciate in the countryside at this time, and I often find that a walk started with the best of intentions for plenty of fresh air and healthy exercise can change into a slow exploration of just a few hundred yards of hedgerow, woodland edge or riverbank.

I am lucky to live in an area with many old hedges, complete with established banks and ditches, and these provide a constant source of interest for any naturalist.

By late August, most birds, with the exception of the doves and pigeons, will have raised their last brood of the season, and it has been particularly encouraging to see, and hear, an increasing population of yellow hammers.

I have, however, greatly missed “our” Spotted Flycatchers this summer, whose absence has broken an annual tradition spanning more than 20 years.

Splashes of colour are now provided by crops of fruits and berries which should, if only the hedges aren’t thrashed too early, provide autumn and winter sustenance for resident and visiting birds.

In the base of the hedge, it appears to have been a good year for Lords and Ladies, or Cuckoo Pint, its short leafless stalks supporting a mass of bright orange berries.

The unusual appearance of this plant has led to it probably having more local names than any other, some slightly mysterious, and some which would be considered far too indelicate for modern sensitivities.

Among the eye-catching discoveries have been several plant galls, the most spectacular being the bedeguar gall, often known as robin’s pin cushion, which grows on the wild rose.

These strange outgrowths look like a mass of wiry fibres protruding from the leaf angles and change in colour from green to bright red.

They are actually home to the grubs of a small wasp, which will remain inside until the spring, when they emerge to lay their eggs in the developing buds to start the whole cycle again.

In spite of the fact that most go unnoticed, large numbers of galls are caused by wasps, sawflies, mites, fungus and bacteria, with each invading or developing organism creating chemicals which specifically affect the host plant.

These have the effect of changing the structure of the surrounding tissue, providing, in many cases, strong protection and nutrition for the inhabitants even through the hardest winters. The story does not end there, for other insects have developed ways of introducing their eggs into the forming galls, which then either live alongside or parasitise the original occupants.

While galls are by no means rare, they tend to remain fairly anonymous, with the possible exceptions of the “witches broom”, a tangled mass of malformed twigs found in the branches of birch trees, and those commonly called oak apples.

The latter are usually wrongly identified as they are, in fact, marble galls, which are small, up to 20mm across, and home to only one female grub.

The true oak apple can be up to 45 mm across, has a more papery surface, and contains several male and female grubs. Considering the wide variety of galls which form on its twigs, leaves, acorns and even roots, I assume that oaks are the most popular host for gall wasps, which, in turn, are just a small percentage of all the insect species which live and feed on this very accommodating tree.

Certainly, it’s true that the more one looks, the more one sees, and I have found galls on a range of other plants, including willow, bramble, and a nearby walnut tree.

A botanist friend tells me that while hundreds of different types of galls have been recorded, there is still much to be learned on the subject.

I find it fascinating that while great excitement is expressed over the discovery of new species of plant and animal in the last unexplored parts of our planet, we have, literally on our doorstep, an area of research just waiting for naturalists, amateur and professional, to fill in some of the gaps.