Part 8

Anthophora pilipes has a very close relative in Anthophora retusa, which also forms large colonies, but it is as a rule less common. These two species are exceedingly alike, in fact it requires some skill on the part of the observer to differentiate their females. They are both black and clothed with black hairs, and both have yellow pollen-brushes, but in retusa the hairs are shorter and not quite of such a deep black as those of pilipes, and the spurs of the tibiae are pale, whereas in pilipes they are black. The males, however, differ widely, although much alike in colour; in pilipes the feet of the middle pair of legs are clothed with enormously long hairs, the basal joint has a dense fringe of black hairs in front and some long black hairs behind (see pl. D, fig. 24); in retusa the basal joint of the middle pair of feet have a fan-shaped fringe of black hairs, and the rest of the joints are clothed with longer hairs, but not long enough to be specially noticeable. A. retusa is visited by the same cuckoo as A. pilipes and also by its rare ally Melecta luctuosa, which only differs from armata {63} (pl. D, 26) in the larger and squarer spots of the body and various small structural characters hardly appreciable except by specialists. The Anthophoras have other parasites besides their cuckoos; one is a beetle, which, however, is rare, and which lays its egg in the Anthophora cells; the other is a very minute member of the Hymenopterous family, whose larva when hatched feeds upon the larva of the bee. Notwithstanding these disadvantages both species are abundant, although retusa is more local than pilipes. A very interesting fact connected with this genus has just been communicated to me by the Rev. F. D. Morice. John Ray, who lived in the seventeenth century, mentions in his book Historia Insectorum (published posthumously in 1710), p. 243, that a large colony of a bee, which from his description was clearly an Anthophora, as he specially calls attention to the great difference between the males and females, inhabited a certain locality at Kilby near "Hill Morton" in Northamptonshire. Mr. Morice, who for many years resided at Rugby, knew Hillmorton, as it is now spelled, well, and tells me that a large colony of Anthophora was in that same locality when he knew it only {64} a few years ago. Of course there is no proof that it has been there throughout the intervening period, but there seems to be no reason to doubt it, and if so it is a most interesting case of a persistent colony.

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{65}

BEES AND POLLEN-COLLECTING

Bees whether solitary or social enter flowers for the sake of the honey in their nectaries and the pollen on their anthers. In some cases the flowers automatically deposit pollen on the bees during the operation, which enables them to fertilize other flowers of the same species, but the pollen which the bee requires for its own use has to be worked for and collected on organs specially adapted for the purpose. These vary very much in the different families and genera; they exist only in the females, and, if the males get covered with pollen, as they often do, it is probably more by chance than purpose, and it is doubtful if it is of any value to the brood, although no doubt useful in fertilizing other flowers. All our bees, as has been pointed out before, are clothed more or less with branched or feather-like hairs, which would appear to be admirably adapted for the collecting of pollen. {66} At the same time some species which have their bodies clothed with branched hairs have simple or spirally grooved hairs on the collecting organ--others collect on very much branched hairs--so that there seems to be no exact relationship between the plumosity of the hairs and their utility in collecting. The collecting brushes are either on the hind legs or, as in some cases, on the ventral surface of the body. In a female Andrena, the hind leg has a tuft of curled hairs near the base of the leg, and a more or less heavy brush on the outside of the tibia or shin (fig. 8). When a female returns after a collecting expedition these specially hairy regions are a mass of pollen grains, and the "beautiful yellow legs", so often remarked upon in some bees, are not always due to the colour of the hairs but to that of the grains of pollen adhering to them. The genera which collect on the under surface of the body have to visit flowers where the anthers lie in such a position that they can transfer the pollen on to it; the pea flower tribe are favourites with them, and also the Compositae. All this section have long tongues so that they are able to reach the nectaries of {67} [Illustration: FIG. 8.] [Illustration: FIG. 9.] plants with long tubular flowers. In visiting these the pollen is often deposited on the back of the bee; this it is able to transfer to its under side by means of the brushes on its feet or tarsi. The arrangements of the humble bees for pollen gathering are altogether different from those mentioned above. They have the hind shin outwardly shining and rather concave, with a series of long curved hairs running down each side of it and partly curving over it, so that they carry their mass of pollen in a sort of basket, scientifically called the "corbicula" (fig. 9); this would be impossible if the pollen were gathered dry, as it is by most of the solitary bees, so the bee moistens it on the flower with the nectar she has been sucking so as to make it sticky, and then transfers it into her basket by means of her foot brushes. The pollen therefore on the hind leg of a humble bee is all in one mass and can be {68} removed as such. When the bee reaches her nest this must of course save her the trouble which the solitary bee must have of cleaning off all the separate grains of pollen which are mixed up among the hairs.

A word or two may be convenient here on the combs and cleaning apparatus of bees. Any one who has watched a bee clean itself will have noticed that the front legs work more or less horizontally--a bee will lower its head and bring its front leg over it with a curved motion--and that it will clean the sides of the face with a sort of shaving-like action, also that the antennae are apparently pulled through the foot-joint in a remarkable way, often many times in succession. Now the foot of a bee consists of five joints, and is clothed with bristly looking hairs. If these hairs be examined through a microscope they will be found to be more or less razor-shaped, having a thick back and a dilated wing or knife-like blade (fig. 10). In some the blade is of some width, and the edge is evidently very sharp: these hairs or spines no doubt do the cleaning work, and admirably adapted they are to the purpose. The antennae-cleaner {69} [Illustration: FIG. 10.] [Illustration: FIG. 11.] [Illustration: FIG. 12.] (it may possibly be used for other purposes too) is a still more wonderful adaptation; in the basal joint of the foot there is a semicircular incision, which, when examined under the microscope, is seen to be a small toothed comb. The foot itself fits into the tibia or shin, and at the apex of the latter is a modified spine which is dilated on one side into a wing, or knife-like blade; this shuts down on to the semicircular comb, and the insect by passing the antennae between the two can clean off anything which may have stuck to it (fig. 11). When we come to examine the other legs we find that the inner surface of their tibiae and tarsi, i.e. that which is nearest the body, is clothed with hairs which have the points dilated and spade-like (fig. 12), which {70} allowing for the different action of the hind legs makes them just as good cleaners as the razors of the front pair; the spurs at the apex of the tibiae, which are known as the calcaria, are also doubtless useful for cleaning purposes, and this is specially suggested by the beautiful saw-like form which they assume in some species; although there is no actual semicircular comb in the first joint of the tarsi, yet there can be little doubt that the spur and this joint in conjunction can act as a cleaning organ very much in the same way as the more elaborate arrangement in the front legs. Any one who has the opportunity of examining the hairs of bees under a microscope will be amply repaid for the trouble in noticing the beautiful shapes and structures which these organs assume. (Figs. 13-18; 17 showing pollen grains adhering.) At one time, when I was specially examining bee hairs, I shaved the various parts of a large number of species and mounted their hairs dry in microscopic slides, merely securing the cover glass with liquid glue; this was twenty years ago, and many are still quite good. It may seem a difficult operation to shave a bee, but {71} the hairs come off very easily, and with a sharp dissecting knife for a razor as many hairs as one wants are almost immediately at one's disposal.

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{72}

ON BEES' TONGUES, AND HOW THEY SUCK HONEY

In order to understand how a bee sucks honey it will be necessary to go into some rather careful details as to the construction of its tongue and mouth organs. These I will make as short and simple as I can, but the apparatus is a very complicated one, and it will be impossible to describe it without a good deal of technical phraseology.

The tongue has always been considered such an important feature in a bee's structure that it has been made the chief basis of their classification. On this subject I will only say that there are three principal types of tongues--a short bifid tongue (fig. 19, 3), resembling those of the fossors; a short pointed one, shaped somewhat like a spear head (fig. 19, 2, 2a); and a long parallel-sided, ribbon-like tongue (fig. 19, 1, 1a). The bees are classified on what is considered to be an {73} ascending scale, beginning with the bifid-tongued species, through those with the short spear shaped tongues to the higher forms, which have this organ elongate and parallel-sided.

The tongue is the central organ of an elaborate combination of mouth parts, which I will now try to explain. If we turn a bee's head over and look at its underside we shall find a deep cavity, filled up with the base of this combination which fits into it. If we extend the tongue (a humble bee is a good subject on account of its large size, fig. 20) so as to draw its base out of the cavity, we shall find that in the edge of each side of the cavity there is articulated a short rod (20, A), more or less dilated at its apex, called {74} the stipes; on the flattened ends of these rods there swings a joint shaped something like the "merrythought" bone of a chicken, called the lora or reins (20, B), to the central angle of which are suspended the pieces of the apparatus which terminate in the tongue. This V-shaped joint can swing over on its feet, and can therefore lie either between the stipites or rods with its angle pointing towards the tail of the bee, or in the opposite direction with its angle projecting beyond them and pointing forwards. It will at once be seen that by this turn of the V the tongue can be projected a distance equivalent to twice the length of the V.

This V-shaped joint varies much in the length of its arms, which are much longer in the long-tongued than in the short-tongued bees.

When we examine the parts that are suspended from this joint, we shall find that the actual tongue is separated from it by two distinct pieces; the first (i.e. that next to the lora) a short joint (the submentum, 20, C), the second (the mentum, 20, D) a long semi-cylindrical joint which holds as in a trough the softer parts at the base of the tongue. From the apex of the mentum {75} project three organs; the central one is the actual tongue (or ligula, 20, E), and on each side are the organs which are called the labial palpi (20, F); these in the long-tongued bees more or less fold over the base of the tongue and protect it. There are two other large and important mouth parts called the maxillae (20, G); these articulate on to the flattened apices of the cardines, outside the articulation of the feet of the lora, and extend on each side of the mentum; they also have flattened blades sheathing, when closed, the whole of the mentum above, as well as the base of the tongue.

So far we have been looking at the back of the head and mouth parts; if we now look at the front we shall see the maxillae; if we open these we shall see the tongue lying between the {76} labial palpi, and at the base of the tongue we shall see two little sheaths called the paraglossae; above these the softer parts lying in the trough of the mentum; from the base of the mentum, connecting with the maxillae, there extends a membrane which entirely invests the spaces between the bases of these organs and extends up to the mouth. A membrane also extends between the stipites and lora, and closes the cavity at the back of the head. The back of the tongue in the act of sucking can be formed into a tube through which, partly, probably by capillary action, partly by the pumping action caused by the dilating and contracting of certain parts of the mechanism, the liquid food is drawn up into the aesophagus. This, I believe, has been shown to be the principle on which all bees, short- or long-tongued, suck up their honey. The subject could be treated at much greater length, and many other structures connected with the mouth parts discussed, but more minute details are unnecessary in an elementary work such as this, and I have therefore limited myself to a description of the broad principles of the process.

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{77}

A DREADFUL PARASITE

Of all the evils to which bee flesh is heir, there can hardly be any so terrible as the effects of the parasite Stylops on the species of Andrena and Halictus which it attacks. This very extraordinary creature, which is now considered to be a beetle, lives during the early stages of both sexes in the body of the bee, which it enters when the bee is in the larval state. Its head protrudes like a minute flat seed between the body segments (fig. 21), and so is visible externally, but the rest of the creature, which is a grub-like larva, rests amongst the intestines of the bee; the female matures in the bee's body and never leaves it. The male, however, when mature, escapes, leaving the {78} [Illustration: FIG. 22. Stylops larva in abdominal cavity: after Perez.] great hole which he inhabited open; he is provided with wings, and I have more than once caught one flying in the open--but to return to our afflicted bee. This may be attacked in either sex, and by one to five of the parasites. I have specimens myself with four parasites in them, and a case of five has been recorded. Mr. R. C. L. Perkins, writing on this subject, says: "On removing the integument dorsally from the bee, the large body of the female parasite will be seen lying above the viscera, often almost entirely concealing them". If this is the condition of a bee nourishing only one parasite, I must leave it to my readers to imagine the state of the poor wretch who is supporting five! The outward appearance of one with several parasites is generally much distorted; the abdomen is very much inflated, and the poor creature is unable to fly any {79} distance, and can only crawl about, or perhaps take short flights of a foot or so. The effects, however, seem to be very different in different cases. I have caught Andrenas with two Stylops in them, flying about as usual and apparently none the worse for their inmates. Probably the position the parasite occupies may make a great difference in its effects on the bee.

The most notable effect produced by Stylops is the alteration in the structure and colour of certain of the bee's characteristic features. In Andrena the males differ very considerably from the females both in form and colouring. They have no pollen-brushes on their legs, and in some few species the face above the mouth is white, whereas in the female it is black. Now the effect of the parasite seems to be to unsex as it were its victims so far as their outward appearance is concerned. This is no doubt due to the internal effects it has on the larva of the bee. Anyhow, if a female is attacked, in most cases the pollen-brush is much reduced, the face tends to become more hairy, and, if it be the female of a white-faced male, spots of white are often produced on the face. On the other hand, {80} if it be a male subject, the hairiness of the face is diminished, the white colour is often reduced or absent, and the hairiness of the legs is increased.

Before the effects of the parasite were recognized, several new species were described simply on specimens of unusual appearance in consequence of its presence.

These effects, however, like the effects produced on the activity of the bee, vary exceedingly in extent. On some the parasite seems to have no effect, in others the alteration in appearance is very great. This, again, is probably due to the position of the parasites and to the pressure they exert on the reproductive organs of the body in the larval state.

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{81}

AMONGST THE BEES AT WORK

Now I feel sure many will be thinking "It is all very well to talk about all these solitary and social bees, but I never see them. I certainly know a humble bee with a white tail and another with a red tail, and a wasp, and perhaps a hornet, but I never notice any others." The reason for this, no doubt, is that people are not as a rule observant, and even if they notice a creature one moment they probably forget all about it the next. If any one goes out on a bright spring morning, late in March or early in April, about 11 o'clock, into a garden well stocked with flowers, it will not, I think, be many minutes before an insect darts on the wing along some border, and, if attention be paid to the flowers, a little black hairy bee with yellow legs, like a small humble bee, will be seen diligently at work sucking honey from one of them. The darting bee, which is of a brownish red colour, gradually {82} fading to grey after a few days' exposure to the sun, is the male, and the black one the female. The male rarely settles, but flies about courting the female. Often two or three males may be seen dodging and crossing each other in their flight. The name of this bee is Anthophora. It is quite a harbinger of spring, and I mention it especially as it so forces itself on one's attention, and there are few who will not meet with it without going especially on its quest.

Another opportunity of seeing several kinds of solitary bees flying together may be secured by standing on a sunny day in front of a sallow bush in full blossom, I mean what is commonly called "palm." Its catkins, when the anthers are out and covered with yellow pollen, are most attractive to all kinds of bees, humble bees, hive bees, and solitary bees, and any one who can manage to watch a sallow bush for some time will realize that there are many kinds of bees at work. Of course it is difficult, without special knowledge, to recognize which are bees and which are flies amongst the many which are coming and going, but the yellow-pollened legs of the female bees will generally betray them, as well {83} as their steadier flight. A fly turns about more rapidly than a bee, and sits down much more abruptly. Bees are very captious about the weather; they do not like an east wind and are, apparently, very sensitive to coming wet. I have often gone out on a bright morning and been surprised to find nothing stirring, and then clouds have come up and proved the wisdom of the bees in staying at home. They also fly very little in cloudy weather, especially in the early spring, when the temperature is reduced by cloud below their fancy. One may be watching a sallow bush and see dozens of insects flying about. A cloud shadows it, and almost immediately they disappear, to appear again as suddenly with the return of the sun's rays. It is interesting to watch bees at work collecting pollen, etc., but if any one wishes to study them at home, their nesting haunts must, of course, be visited. These are so various that it is impossible to point them all out, but the best locality to select is a sandy bank facing south. In June or July such a bank is often alive with bees, sand-wasps, etc.; here, again, we want sunshine or the bees will stay in their holes. {84} Even when dull, however, it is a very interesting spot, and we can notice the numbers of holes bored in the bank, and their different sizes and shapes; most of them are round, but some sandwasps make very irregular holes. If we look closely at some of the holes we shall see something closing the aperture, and, if we are too inquisitive, that something will disappear down the hole like lightning; it is the face of the owner of the burrow waiting to come out for the first ray of sunshine, but the owner is very timid and it will be some minutes before she puts her face so near danger again. In most of the sandwasps the face is clothed with bright silvery, or sometimes golden, hairs, and it is a very pretty sight to see these little silvery faces peering out of their burrows. Again, one may sometimes notice a little stream of sand emerging from a hole; this is from some bee who is enlarging her domain or clearing out some of the sand which occasionally falls in. In some cases this ejection of sand is done with a great deal of action: the sand comes streaming out and then the bee follows, quite up to the mouth of the passage, kicking out the sand as hard as it can. {85} The moment, however, that the sun comes out the whole bank is full of life; and just as in the case of the sallow bush, one wonders where it has all been during the shadow. Bees will now be seen flying home laden with pollen; they will pause at the opening of their burrow and then disappear suddenly into its depths. In a very short time they will reappear quite clean and ready for another journey. Their cleaning apparatus must be wonderfully well adapted to its purpose. I have often had to remove the pollen from a bee's leg to see what colour the hairs are, and it takes some time even to brush enough of it off to ascertain this, and yet the natural cleaning process seems to take no time in comparison. But to return to our bank, numbers of bees will be seen coursing up and down and hardly ever settling; these are males paying what attention they can to any females who have time to attend to them, and often falling foul of other males intent on similar pursuits. If one has good luck in the choice of one's bank an elegant wasp-like creature may occasionally be seen amongst the others; this is one of the cuckoos. The flight of all the cuckoo bees is peculiar; it is much {86} quieter and slower than that of the hosts, and a cuckoo may easily be seen solemnly flying up and down the bank, over the various holes, no doubt watching for the proper opportunity to enter one, and deposit its egg in it. This deliberate flight seems a curious habit in a creature which one would think would wish to escape detection. If it seemed to inspire fear in the mind of its host it would be different, but they appear to fly about together unconcerned at each other's presence, and the cuckoo sails along demurely and imposes on its hosts' labours without any apparent resentment on the latter's part; both seem to accept their relationship as a matter of course. Another very interesting frequenter of sandy banks is a pretty little stout sandwasp, about a quarter of an inch long, called Oxybelus. It has a very bright silvery face which shines most brilliantly in the sun, and the body has a row of white spots on each side, and it brings flies back to its nest. It is very active and common, and may often be seen with its fly going back to its hole. There is a rare species of the same genus, which is clothed all over with silvery hairs, and this in some places, curiously {87} enough, selects as its victim a fly which is also coated with silver. There are, of course, many other inhabitants in such a bank as this. There are sure to be ants, which are always interesting to watch, and probably now and then a Pompilus will appear on the scene. These exceedingly lively creatures which run at a very rapid pace, vibrating their wings as they go, and taking short flights between the runs, are on the hunt for spiders. They will be seen to forage amongst any grass or herbage there may be on the bank, and if they can only secure a spider it is stung and paralyzed and carried off at once to the nest. Of course every sand bank will not yield a great number of insects, but some, especially in sandy districts like Woking, Oxshott, and other parts of the Surrey commons, and the New Forest, simply teem with life--and would repay any one for hours of watching and observation.

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