Wild Bees, Wasps and Ants Part 1

Wild Bees, Wasps and Ants.

by Edward Saunders.

PREFACE

The object of this little book is to give in as simple a form as possible a short account of some of the British Wild Bees, Wasps, Ants, etc., scientifically known as the _Hymenoptera Aculeata_. Of these the non-scientific public rarely recognizes more than the Hive Bee, the Humble Bee, the Wasp, and the Hornet, whereas there are about 400 different kinds to be found in this country, and they can be recognized by any one who is disposed to make a special study of the group.

The author has not hesitated to make free use of the experiences of others in regard to the habits of the insects he describes, and he has not thought it necessary in each case to make separate acknowledgment of this. He takes this opportunity of thanking Mr. H. Donisthorpe and Mr. F. W. L. Sladen for a.s.sistance in the chapters on Ants and their Lodgers, and Humble Bees, respectively. {vi}

These pages are written only for the non-scientific, as the scientific entomologist will be already familiar with the elementary facts recorded; but it is hoped that they may be of interest to lovers of Nature who wish to know a little about the insects they see round them and how they spend their lives. Of this knowledge very little exists, as the sc.r.a.ps which have been here brought together evidence. There is an immense field open for research and observation, and the writer of this little book will be very glad if the following pages should encourage any one to take up the subject and add to our present scanty stock of information.

EDWARD SAUNDERS.

ST. ANN'S, WOKING.

THE SUBJECT IN GENERAL

I think I ought here to say why I propose to limit myself to an account of a certain portion only of the Hymenoptera. The reason for this, in the first place, is that the section which I have selected is the only one of which I have any special knowledge; it consists of the bees, wasps, ants and sandwasps, four groups which make up the stinging section of the order--or perhaps more accurately, which have poison bags connected with their egg-laying apparatus or _ovipositor_. Another reason for their selection lies in their nesting habits; these enable one to get a further insight into their economy and ways than can be obtained from those of almost any other group or order--at any rate they make them comparatively easy to study; one can, so to say, find these little creatures at home, whereas in most orders there seems to be no definite home to which the {2} individuals may be traced; a great advantage also in selecting the stinging groups for study is that they are creatures of the spring and summer, and of the suns.h.i.+ne, so that the weather which tempts them out to their duties is of the kind most agreeable to those who wish to investigate their habits.

The habits of the hive bee have not been touched on, as so many excellent treatises have been written on them that any observations here would be superfluous.

Although these groups are distinguished by their stinging habits, it is only the female that possesses a sting--the male is a most harmless creature and quite incapable of injuring any one. A male wasp or even a male hornet may be handled with absolute impunity, only it is wise to be certain as to the s.e.x of the individual before presuming to play with it too much! A word here may perhaps be said about stinging. People often talk about a gnat stinging or a stinging fly; it may be difficult to define exactly what "to sting" means, but the writer has always considered that a sting is inflicted by the tail end of the creature or a {3} bite by the mouth. A fly or gnat no doubt inserts its proboscis into one's flesh just as a wasp does its sting; but the actions of such opposite parts of the body surely demand distinct names. As we have been alluding to flies it may not be inappropriate to say here that all the creatures we are going to consider have four membranous wings except the worker ants and a very few forms which are comparatively seldom met with. By this character they may at once be known from flies, which have only two membranous wings. The large brown "drone flies", so often seen on the windows of our rooms, especially in autumn, and which most people mistake for hive bees, to which they certainly bear a considerable general resemblance, may be detected at once by wanting the two hind wings of the bee.

The "aculeate", or stinging, Hymenoptera, are divided into sections and families according to their structure; but the groups which stand out most clearly in regard to their habits are the solitary and social species, the predaceous and non-predaceous and the inquilines or cuckoos. {4}

The vast majority of the aculeate Hymenoptera are what are called "solitary", i.e. one male and one female alone are interested in the production of the nest; but there are also three "social" groups--the ants, the true wasps, and the humble and hive bees.

These are called social because they form communities and all work together towards the maintenance of the nest. In the social species there are two forms of the females--the queens and the workers; these latter have the ovaries imperfectly developed, and in the humble bees and wasps they only differ outwardly from the fully developed females or queens by being smaller. In the ants, however, the workers are wingless, and of a very different form from that of the queen. The role of these workers seems to be to do the general work of the nest; they have been known to lay fertile eggs, but the resulting offspring has always been male.

Between these conditions of solitary and social we know of no actually intermediate stages. We do not seem to see any attempts on the part of solitary bees to become social or vice versa. The only condition known which {5} could possibly be considered as intermediate is shown in certain species where a number of individuals make their nests close to each other in some particular bank, forming a colony. These colonies are sometimes very extensive, and the burrows of the individual bees very close together; it has also been shown that the burrows sometimes unite--at the same time there seems to be no positive evidence that there is any work done in the colony which could be considered as done for the common good.

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THE SOLITARY GROUPS

All the solitary kinds appear to feed themselves on vegetable juices, honey, etc., but there is a well-marked division between those who provision the cells of their offspring with insects, either fully developed or in the larval stages, and those who provision them with the pollen of flowers, honey, etc. The theory is that originally all fed their cells with insects, but that by degrees the more progressive found that the food which suited themselves would equally nourish their offspring, and accordingly provided them with vegetable nourishment. We find no intermediate stages. A certain cla.s.s still goes on feeding on the old principle. The members of this cla.s.s are known as "_fossors_" or diggers, while those which feed on the new principle are called "_Anthophila_" or flower-lovers. These are not very happy names, as many of the _Anthophila_ dig out holes for their nests just {7} in the same way as the _fossors_ do, and many of the _fossors_ are found in flowers, apparently enjoying them just as much as a truly anthophilous species would, although no doubt often with the ulterior object of capturing some insect for their young! Still these names are known as representing these two sections all over the world, and therefore it is better to keep to them even if they are not as descriptive as one would like them to be.

The _fossors_, or "diggers", have all comparatively short and bifid tongues, and have, as a rule, little in the way of hairy covering, and what hairs they have are simple and only in very rare instances branched or feather-like. The hind legs of the females are not modified in any way so as to enable them to collect pollen, their legs are usually long and slender, and they are admirably adapted to their life habits of hunting spiders, insects, etc., for their young.

On the other hand, the _Anthophila_ or "flower-lovers", are specially adapted for pollen collecting. Their tongues vary from a short form like that of some _fossors_ to the long tongues of the humble bees. Their hairs are always plumose {8} or branched on some part of the body and the hind legs of the females in most species are provided on the tibia or s.h.i.+n with a special brush on which pollen may be collected. In some of the long-tongued bees, however, this brush occurs on the underside of the body instead of on the tibia. The pollen-collecting arrangements of the different genera of the _Anthophila_ and the corresponding organs for cleaning off the pollen again are amongst the most interesting instances of modification and adaptation: some of the more striking of these will be mentioned later on. (See pp. 65 _sqq._)

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THE SOLITARY BEES

The life-history of an ordinary pair of solitary bees is, roughly, as follows: I will take for an example one of the spring species of _Andrena_.

Many people know the little red bee, which for some apparently unaccountable reason suddenly appears in myriads on their lawn or gravel path, throwing up little mounds of finely powdered earth--in this respect being quite different from worm casts, which are formed of wet mould and the particles of which cling together--sometimes causing considerable alarm as to the possible effect on the lawn. These have hatched out from burrows made by their parents in the previous year, the mouths of which have been filled up with earth and therefore are quite invisible till the newly fledged bees gnaw their way out. They, in their turn, are now making fresh burrows for their own broods; possibly they infested some one else's lawn the year before or were only in comparatively small {10} numbers on the lawn under notice and so pa.s.sed unrecognized. They may safely be left alone, as they never seem to breed many consecutive years in one such locality: probably the treatment of a lawn does not suit them, mowing and rolling upsetting their arrangements. We will now consider these arrangements. The female bee, so soon as she realizes that she is charged with the duty of providing for her future offspring, makes a burrow in the ground, and the earth thrown up from the tunnel forms the little heap which is so observable; this burrow varies in depth from 6 to 12 inches and has short lateral branches; each of these she shapes, more or less, into the form of a cell, provisions it with a small ma.s.s of pollen mixed with honey for the maintenance of the larva when hatched, and lays her egg; she then seals up that cell and proceeds to the next, and in this way fills the burrow up until pretty near the surface. The bee caterpillar when hatched is a white grub-like creature which, after devouring the food provided for it, becomes more or less torpid; it then makes its final change of skin, after how long a period is probably uncertain, and appears in the nymph stage. {11} [Ill.u.s.tration: FIG. 1. Bombus, larva and nymph: after Packard.]

This stage corresponds to the chrysalis of a moth or b.u.t.terfly, the creature being shortened up and rather more like the perfect insect compacted into the smallest form possible. People are often misled into the idea that the caterpillar forms the chrysalis over its former self, whereas the chrysalis has been all the time forming inside the caterpillar and only shows itself when the final skin is shed; of course some caterpillars spin a coc.o.o.n over themselves before they change their skin, but then the true chrysalis is found inside the coc.o.o.n. A curious fact connected with the change from the nymph to the perfect insect is that this takes place sometimes as early as August in the year preceding their appearance; so that cells dug up in August may contain fully fledged insects which are not due to appear till April or May of the following year. It is wonderful also how long life can be {12} sustained by these creatures in the "full-fed larva" condition. Some years ago I collected a number of pierced bramble stems in order to breed out some of the small "sandwasps" which nest in them. On opening them in May, when the perfect insects are generally ready to appear, I found that several of the larvae had rather shrunk up and had not changed into nymphs. These I left in the stems, covering them up again, and they appeared as perfect insects in the May of the following year.

The account given of the nesting habits of the above _Andrena_ of our lawns, etc., is more or less true of nearly all the solitary bees. Their methods vary, some burrow in the ground, some in old wood, some in snail sh.e.l.ls, some in bramble stems or straws or the hollow stems of various plants, some in holes or crevices in walls, etc., and their methods of building their cells vary exceedingly: all of these are of great interest and some display an ingenuity which is quite surprising. Of these special nesting habits some of the most striking will be mentioned later on.

Before leaving these general remarks on the {13} solitary bees the habits of two genera must be specially noticed, as they differ in an essential point from those of the others. These are known to entomologists under the names of _Halictus_ and _Sphecodes_.

In most species of these the males and females of the new brood are not hatched out till after midsummer, and no work is done for the provisioning of new burrows that autumn; but the female, after having undertaken the duties of maternity, hibernates, i.e. goes back into a burrow and lives there till the next spring, the males dying off before the winter. In the spring the [female] wakes up and does the necessary work for the future brood just as any ordinary spring bee would--but there are no attendant males--the duties of that s.e.x having been performed in the autumn. The larvae contained in these burrows hatch out after midsummer and therefore never spend a winter in the ground. In this respect they resemble the social bees and wasps, about which more hereafter; in the meanwhile a few words must be said about the cuckoos or inquilines, which are perhaps the most interesting creatures of all.

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THE CUCKOO BEES

These cuckoos live at the expense of their hosts. The mother of the industrial brood makes her cell and provisions it, and lays her egg. The cuckoo bee manages to enter also and lay her egg in the same cell, the usual result being that the cuckoo devours most of the food instead of the rightful offspring, which gradually gets starved and dies, the cuckoo appearing in its place; but there have been cases, how frequent they are is difficult to say, in which both offsprings have emerged.

The whole problem of the relations.h.i.+ps between host and cuckoo is most interesting. In some cases the cuckoos are so like their hosts that it is difficult to tell one from the other, in others they are so unlike that it is difficult to trace any resemblance between them. There are a great number of different kinds of cuckoos, and most of them select a special host to a.s.sociate {15} with, and are never found except with that species.

There are, however, cases of cuckoos which visit the nests of more than one host, and cases of hosts which are visited by several kinds of cuckoos. In the short-tongued bees, with the exception of _Halictus_ and _Sphecodes_, the cuckoos are quite unlike their hosts both in form and colour. In the _Andrenas_ (the lawn bee being one of them) the hosts are clothed with reddish, or brown and black, hairs, and are of a more or less stout build (pl. B, 15, 16). The cuckoos are elegant in shape, almost devoid of hairs, and most of them are striped with yellow or brown across the body so that they present a wasp-like appearance (pl. B, 18). Species more unlike one another than host and cuckoo one could hardly imagine; still this stranger seems to get access to the nest of its host without opposition. In a colony of _Andrena_ one may see the cuckoos (which rejoice in the name of _Nomada_ or wanderers) flying about among the females of the industrious bee, and no alarm or concern appears to be felt by the latter. As we go up in the scale of bees, i.e. towards the more specialized, and arrive at those with longer tongues, the {16} cuckoos are found as a rule to resemble their hosts more closely, both in colour and structure, and when we reach the social genus _Bombus_ (i.e. the humble bees) we find the cuckoos so like their hosts (pl. D, 30, 31) that even entomologists of experience mistake one for the other. _Apis_ (the hive bee) has no cuckoo. It seems to be theoretically probable that both cuckoo and host once originated from common parents; this is suggested by the similarity of structure of certain parts of both host and cuckoo, even in cases where they are otherwise most dissimilar.

_Andrena_ and _Nomada_, for instance, which are very unlike, as stated above, agree in both having very feeble stings and in possessing three conspicuous spines on the upper and posterior edge of the orbit of the larva. Also, although _Andrena_ the host has a short tongue, and _Nomada_, its cuckoo, a long one, the appendages (_l.a.b.i.al palpi_) of the latter's tongue are framed on the same plan as those of the tongue of _Andrena_, and are quite unlike those of the other long-tongued bees. On the other hand, the cuckoos of the social species resemble them so closely in structure as well as {17} appearance that it is more necessary to search for points of difference than of similarity. There is only one case known of a cuckoo wasp, and that resembles its host even more closely than do the cuckoos of the humble bees. All these points certainly suggest the probability that the social bees and wasps and their cuckoos adopted different habits at a much more recent date than the solitary species, and therefore have not had so much time to become differentiated in structure. The only short-tongued bees which have cuckoos of similar structure are the species of _Halictus_ (pl. B, 12); their cuckoos, _Sphecodes_ (pl. B, 11), are closely allied to them, but then _Halictus_ and _Sphecodes_ are most peculiar genera; although short-tongued, their females spend the winter in the earth, as do the social bees and wasps (see p. 13), and they colonize largely, which may prove to be a step towards socialism.

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THE FOSSORS OR DIGGERS

In many respects the insects of this section adopt the same methods as the solitary bees so far as the construction of their nests is concerned, but the food brought home for their offspring is animal instead of vegetable.

In order to supply their larvae with "fresh meat" these little creatures, when they have captured a suitable prey, sting it in such a way that it becomes paralyzed, but does not die; after provisioning a cell with the necessary number of these paralytics, the mother lays her egg on one of them or amongst them, and closes up the cell. In consequence of this wonderful maternal instinct, foresight, or whatever the faculty may be, the larva when hatched finds fresh food ready for consumption. The various species provision their nests with different kinds of foods, and some appear to be most fastidious in their selection, and are said never to err in choosing {19} species of some particular family, thereby displaying a discernment worthy of any advanced entomologist. Some provision their cells with beetles, some with gra.s.shoppers, others with spiders, caterpillars, plant lice, etc.

The strength possessed by the female fossor must be proportionately enormous, as she can bring back to her burrow, after paralyzing them, insects many times her own size. It is a most interesting sight to see the excitement and flurry of the captor as it tries to drag along some huge prey to its nest. I remember seeing one dragging along a good-sized caterpillar, of a noctuid moth, over rather rough ground: the poor creature had a difficult job; it had to go backwards itself, and pull the body of the caterpillar, after it--its behaviour was very much like that of an ant which has a large burden; at times it would loose its hold of it and try it from some other quarter; however, by degrees, by pulling and tugging, the prey was safely brought home, but the force expended must have been very great. Many species, however, hunt insects of much smaller size than themselves, and it is those which take a fancy to gra.s.shoppers and {20} caterpillars which seem to be the most doughty in deeds of force. One, a very rare kind in this country, sets its affection especially on the honey bee as a prey; the two insects are about equal in size, but the hive bee must be a dangerous foe to attack, and one would have thought as likely to sting its captor as its captor would be to sting it; also one would imagine that a hive bee, unless thoroughly paralyzed, would be a dangerous subject for a juvenile larva to commence making a meal upon! but whether the venture ever turns out unsatisfactorily there are no data to show, so far as I am aware. The larvae must vary very much in their tastes; one can imagine that a nice juicy caterpillar, or even a good fat gra.s.shopper, may be appetizing and easily a.s.similated, but one can equally fancy that the larvae, who wake up to find their food consisting of small hard beetles, may feel more or less resentment against their parents' ideas of dainties for the young! Still they seem to thrive on it, and come out eventually as exact likenesses of their parents. A large number of the fossors inhabit dry sandy wastes, such as the dunes along the sea coast at Deal, Lowestoft, {21} etc.; many of these, when they leave their burrows, throw up some sand over the hole so as completely to cover it; how these insects find the spot again after a lengthy chase after spiders or other prey is a marvel; and yet those who have observed carefully say that they come home from long distances with unerring precision. No sense of which we have any knowledge, however accentuated, seems to explain this. To be able to arrive back at a home in an extensive arid sandy plain, where no outward sign indicates its whereabouts, must surely require perception of a different nature from any of those with which we are endowed. Some fossors are subject to the depredations of cuckoos, just as the solitary bees are, but their cuckoos are rarely of aculeate origin. The only ones which I have had any opportunity of studying are the species which nest in bramble stems. The cuckoos which a.s.sociate with them are some of the smaller jewel flies and _Ichneumons_: the habits of both these differ from those of the aculeate cuckoos, the jewel flies devouring the larva of the aculeate and the _Ichneumon_ laying its eggs in it. The fossors {22} [Ill.u.s.tration: FIG. 2.]

vary exceedingly in size, shape and colour. Our largest species are about an inch long and our smallest about the eighth of an inch, nearly all having the body where it joins the thorax constricted into a very narrow waist; this is sometimes of considerable length. In one genus known to entomologists by the name _Ammophila_ (fig. 2) or "lover of the sand", the waist is practically the longest part of the body, so that looking at one sideways as it flies along, one could almost be deceived into thinking that there were two insects, one following the other (cf. pl. A, fig. 7). In colour, there seem to be three dominant schemes: Black (cf. pl. B, fig.

17); black with a red band across the body (cf. pl. A, fig. 7); and black banded with yellow, like a wasp (cf. pl. A, figs. 6 and 8, etc.) In some the yellow bands may not be complete, and appear only as spots on each side of the body segments, or the red band may be almost obliterated, or the black species may {23} [Ill.u.s.tration: FIG. 3.] [Ill.u.s.tration: FIG. 4.] be more or less variegated with yellow spots on the head and thorax, but as a general rule all our species fall into one or other of these colour schemes. The females of some of our sand frequenting species have beautiful combs on their front feet, each joint of the tarsi having one or more long spines on its external side (figs. 3 and 4). These are of importance to them in their burrowing, as they enable them to move with one kick of their front leg a considerable amount of the dry sand in which they make their nests. Although sandy commons, etc., are the resort of many fossors, others may be found burrowing in wood or in hard pathways or banks; in fact, like most other insects, some of their members may be found almost anywhere.

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THE SOLITARY WASPS

The ordinary wasps are acquaintances of every one, but the solitary or keyhole wasps are not so well known, although they are far from uncommon.

They are little narrow black insects striped across the body with yellow, belonging to the genus _Odynerus_ (pl. A, 9), and might hardly be recognized as belonging to the same family as the true or social wasps.

Still they have considerable powers of stinging, and fold their wings lengthwise when at rest like their larger relatives. I dare say some people may have noticed that a wasp's wing sometimes a.s.sumes a narrow straight form, quite unlike what it is when expanded. This is due to the wasp being able to fold its wing lengthwise like a fan. The wasp tribe are, so far as I know, the only stinging Hymenoptera which have this power.