WASPS AND WEATHER.
THE old belief is that a good year for wasps is a good year for partridges, and on the whole the rule holds good. The same conditions, warmth of sunshine and freedom from heavy rain or prolonged wet weather, are favourable alike to sitting partridges and nesting queens. But there are excep- tional years, and it looks as if the present year will be one of them. It has actually been too dry for the partridges, and in many places in England the big coveys of seventeen and eighteen birds which promised so well have dwindled down to five and six—the reason, doubtless, being the lack of insect food which is a necessity for the health of the young birds. This is a consequence of summer drought which possibly was not so frequent in former years, when the use of natural rather than artificial manure was the rule on arable lands. But it is a consequence which has
very little effect upon wasps. The food of wasps consists, of course, largely of insects, particularly house flies, but they do very well, too, with fruit and sweetatuffs of various sorts, and this year they have been particularly flourishing and abundant, so that the taking of nests has been a matter needing diligence and spirit. The present writer has joined in work over only a small area of sixteen acres or so, but in that area thirty-five nests have already been taken, and there are others waiting either for discovery or the usual treatment, which is a very simple method with cyanide of potassium. In all there will be probably forty nests destroyed by the end of August, and if, as seems to be the case, at all events in the immediate neighbourhood, there is the same proportion of nests to acres over a large stretch of country, the calcula- tion of the numbers of wasps helped into existence by a hot summer becomes a matter of simple arithmetic. An average wasps' nest holds six or seven tiers of comb, and a very large one eleven combs. The combs, too, vary in size, but perhaps 2,000 wasp grubs per comb would not be an exaggerated estimate, so that a community of 10,000 or 12,000 wasps would not be an exceptionally large nest in September, when most of the grubs have been hatched. Indeed, some have estimated the full complement of a big nest at any number between 30,000 and 50,000. But taking the smaller estimate, and reckoning the population of wasps per acre at only 20,000, it is not difficult to arrive at a rough guess at the damage done by wasps in a hot summer to, say, an orchard of plums or fruit on garden walls.
Scientific methods of taking wasps' nests are many in number, but none of them compare favourably in certain respects with the schoolboy methods of a generation past. Cyanide, petrol, and sulphurous acid gas have their merits, but gunpowder once was the beat of all Gunpowder was the sporting way. It meant work in darkness, preparation of instruments, the laying of a train or a fuse, a proper frame of suspense before flame, noise, and explosion, and after the explosion there was a very honourable risk of stings. It was a simple method, but failure was easy. The first thing to do was to locate the nest. Then a bottle was procured, generally from the medicine cupboard, and was filled with ordinary black powder, such powder as schoolboys of the present day do not handle, much less manufacture for themselves after the true recipe; then a cork with a notch cut in it was placed in the bottle, and in the notch a fuse. With the bottle well and truly prepared, it was necessary to wait for darkness, until all wasps should be gathered home ; then, with trousers very tightly packed inside his socks, the carrier of the bottle approached the nest, enlarged the hole with a spade, generally waking up several somnolent wasps in the process, and placed the bottle in the hole. A sod was then placed over all, the projecting fuse was lighted, and events were then watched from a convenient distance. After a minute or two the whole thing blew up in the most satisfactory way; if it did not, it was necessary to make an investigation, when it was possible that the explosion might take place in a very unexpected manner. These risks were naturally to be recommended, but it is possible that they were more appreciated twenty or thirty years ago than they would be to-day. The easy way to-day is with cyanide of potassium; but that, too, as a writer signing himself " H. P. G." showed in an amusing article in the Field some two years ago, can involve some very sporting work in tracking out distant nests from the movements of a single insect. Cyanide of potassium as a means of destroying nests is sometimes looked upon with suspicion as being dangerous to other creatures besides wasps, but if it is used carefully there is no risk whatever. It has merely to be dissolved in water, when the mixture can be carried about in a bottle—a hock bottle is a convenient size and shape—and if a little is poured on a small piece of rag or cotton wool, all that has to he done is to place the soaked rag or wool in the entrance of the nest and every wasp belonging to that com- munity is doomed. The insects fly to the hole, hover over it for a second or two, and drop dead. None escape from within, or if one stronger than his fellows manages to rush through the fumes, his rush is all ; be dies as he flies out. In a few hours the whole nest can be dug out, when it is best dropped into hot water and then buried. The fumes will have killed all the adult wasps, but the grubs remain unaffected, and those in the pupa stage, which may be distinguished from the younger grubs by the silken door over the mouth of their cell, will emerge none the worse, possibly to found other colonies elsewhere.
Next to schoolboys and scientific wasp-hunters like "H. P.G.," the best wasps' nest-takers are badgers. Badgers need no cyanide. They merely find a nest, scoop it out, and eat the combs full of grubs with great relish. Nothing is left. The writer on a morning early this week found in a few yards of a woodland ride three nests scooped out by a badger, with only a few fragments of dry comb and the paper envelope of the nest scattered outside the bole to show what had happened, The interesting point as regards these particular nests, however, was that the badger seemed to have chosen the nests of only one species of wasp, and to have left the nests of other species alone. There are four species of wasps widely distributed in the south of England, Vespa vulgaris (the common wasp), V. germanica (perhaps as common, but a larger insect), Y. rnfa (a reddish variety), and V. sylvestris (which hangs its nests in trees). The three nests scraped out by the badger belonged to germanica, which builds in holes only just under the surface of the ground, while there were two other nests close by belonging to V. vulgaris which he had left undisturbed, possibly because vulgaris builds in deeper holes, not so easily discovered and scooped out.
Fruit-growers, no doubt, cannot be expected to suffer wasps gladly, and for that reason it is probable that the rewards offered in spring for the dead bodies of queens will continuo to be a source of income to school children ; though there is certainly another side to the question. The queens which are killed in April and May are, of course, those who were fertilized in the previous autumn and have hibernated. The proportion of these queens to the number of worker wasps which go through their life cycle in the previous year is a point which does not seem to have been fully determined. The writer has dug out nests which appeared to contain the grubs only of worker wasps; on the other band, one rather small nest dug out last autumn contained only queens. Would these queens • have mated in due course with males from another colony, or would other cells containing male wasps and workers have been added in the course of time to the queen cells ? It is unfortunate that the doings of wasps in their nests cannot be observed with the same convenience as those of bees. Possibly if their habits were more thoroughly understood we might even decide that we ought not to offer pennies for dead queens .
in April. It is certainly rather a contradictory proceeding that while we urge one another to "kill that fly," we do our best to end the existence of a scavenger who is the fly's arch- enemy. The better spirit in which to regard wasps should surely be that of a friend of the writer, a gardener, whose attitude to even the most formidable of wild creatures is one of tolerant inquiry. Not long ago be had observed on a felled larch a large sawfly, Sirex gips, which to those unacquainted with it appears to be a super-wasp of a very terrifying appearance. He brought it carefully in his hand to be inspected. " Some of them say it's a hornet," he remarked, regarding it in his closed fingers. "Is it a hornet ? " He was told it was not. "I thought it wasn't," he said, and let it fly again.
Previous page
