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BEL-KILLER. DESCRIPTION OF THE IXSECT. given, that they may not be confounded with any other species which may be closely similar to them.
They measure to the end of the wings 0.85 to one inch, and to the end of the body 0.95 to 1.15, the males being rather smaller than the females. The head is short and broad, shaped like a plano-convex lens, flat on its hind side and convex in front. Its summit or crown is deeply excavated; leaving a vacant space between the upper part of the eyes, in the middle of which excavation are the ocelli or eyelets, appearing like three black glassy dots placed at the corners of a triangle. The ground color of the head is yellow. All the face below the antennæ is covered with long hairs, forming a moustache of a light yellow color, with a tuft of short black bristles at the mouth, and on each side are whiskers of a yellowish gray color. The base of the head has a sort of collar formed of radiating gray hairs, and behind the upper part of each eye is a row of black bristles. The eyes are large and protuberant, occupying two-thirds of the surface of the head, and are finely reticulated or divided into an immense number of minute facets. The antennæ are inserted at the anterior edge of the excavation in the crown of the head. They are small, scarcely reaching to the tase of the head if turned backward. They are black and composed of three joints, the first one longest and cylindric; the second shortest and obconic; the third thickest and egg-shaped, its apex ending in a bristle which is about equal to the antenna in length, and is slightly more slender towards its tip, where it becomes a little thickened. The trunk or proboscis is as long as the head, its end projecting out from the bristles of the face. It appears like a long, tapering tube of a hard crustaceous texture, black and shining, blunt at the end, with a fringe of hairs around the orifice. In one specimen the tongue protrudes from the orifice in the end of the trunk, sharp pointed and like the blade of a lancet in shape, hard, shining and black. The thorax or fore body is the broadest part of the insect, and is of a short oval form, with bluntly rounded ends. It is of a tarnished yellowish brown or butternut color, with two faint gray stripes along the middle of the back, alternating with three darker brown ones. It is bearded with black hairs and posteriorly with long yellowish gray ones, which are interspersed with black bristles. The abdomen or hind body is long, slender and tapering from its base in the male, and is more broad and somewhat flattened in the female. It is black above and covered with prostrate hairs, which are dull yellow in the male and gray in the female. On the sides and beneath the ground color is dull yellow in the male and gray in the female, and clothed with gray hairs in both sexes. The two last segments, the eighth and ninth, are conspicuously protruded, making two or three more segments than are usually visible externally in insects, In the female these segments taper to an acute point, and are black and shining. In the male they appear like a cylindrical tube with a projecting valve underneath at the base, and are coated over with dull yellow hairs, and on the upper side with silvery white ones, pressed to the surface and forming a conspicuous oblong spot of this color, which is two-lobed or notched at its end. And in the dead specimens before me three bristle like processes BEB-KILLER. LEGS AND WINGS DESCRIBED. DELIGHTS IN THE SUNSHINE. over a tenth of an inch in length, of a tawny yellow color, polished and shining, project from the blunt end of the body. These are termed a three pronged sting in the above letter. But the magnifying glass shows they are abruptly cut off at their ends and do not taper to a sharp point capable of piercing the human skin. The legs are long and stout and of a pale, dull yellowish color. The thighs in the males are chestnut brown, and on • their anterior sides they are dull black in both sexes, the hind pair being
entirely black, except a stripe of dull yellowish along the under side. The hind shanks also are frequently black on their anterior sides. The legs are covered with gray hairs and have several black bristles in rows running lengthwise. In the males the four anterior shanks and feet have the hairs yellow, and on the feet the bristles also are of this color. The wings are long and narrow, and in repose are laid flat, one upon the other. They are transparent, with a smoky tinge, and are perceptibly darker at their tips. Their veins are black, except the parallel ones in the outer border, which are dull yellowish brown. The broad pane or panel at the tip of the wings, which is technically termed the second sub-marginal cell, rapidly narrows as it extends forward into the wing, for two-thirds of its length, the remaining third being quite narrow, with its opposite sides parallel. Along the vein which forms the boundary of this cell on its outer side, is a perceptihle smokiness, which is not seen along the sides of the other veins. This vein is slightly bent in the form of a bow two-thirds the length of the cell, when it abruptly curves in the opposite direction, and is then straight the remainder of its length. A veinlet connects it to the next longitudinal vein, thus forming between the anterior portions of these two veins a third sub-marginal cell, which is very long and narrow.
The arrangement of the veins in the wings, forming three submarginal cells as above described, induces me to refer this species without hesitation to Macquart's genus Trupanea; although the silvery white spot on the tip of the male abdomen would indicate it to pertain to the genus Erax, as restricted by the same author.
The brief note of our correspondent gives us no particular information upon the habits of these flies or the manner in which they attack and kill the bees. But the members of this Asilus group are all so similar in their habits that we are aware what the operations of this species will be. And some account of the habits of these insects may be of sufficient interest to the reader to be here related.
These Asilus flies, like some others of our most rapacious insects, particularly delight in the hot sunshine. One or two evidences of this may here be adduced.
Flies of this kind are rare in my vicinity. I suppose I might hunt for days without being able to find a living specimen. And I do not recollect to have ever seen one of them, hitherto, about my house or yard. Three days ago, however, when occupied in preparing this account, I casually spread some damp newspapers before my door to dry in the hot sun. On stepping out to gather up these papers I was most agreeably surprised to see alighted upon one of them and basking in the sun, what proves to be &
BEE-KILLER. ITS FETID ODOR. GRUEL MODE OF KILLIXG ITS PREY. species of Trupanea which I had never met with before and which is closely like though probably distingt from this Nebraska Bee-killer. The genial warmth reflected from the white surface of the paper lying in the clear sun had evidently attracted it to this unusual situation.
So late as the month of October, ten years ago, upon a clear warm day, in a sunny nook upon the south side of a forest, I came upon quite a num. ber of the Erax rufibarbis, flying about and alighting upon the leaves—a. species I have never met with except in that instance. They were warmed into such quickness of motion, and were so extremely vigilant and shy of my approach, that with my utmost skill I was able to capture but two in, dividuals which were impeded in their movements from being paired to. gether. I infer these Nebraska flies to be common and far less wary than the species alluded to~else our correspondent would have been unable to secure two individuals of each sex to transmit to us. And I suspect these specimens were obtained when they were copulated. If so, it is probable that the three sting-like bristles which I have described above, are not protruded and visible externally, except at such times.
In flying, these insects make a very loud humming sound, which can scarcely be distinguished from that of the bumble-bee; and when involved within the folds of a net, they atter the same piping note of distress as does that insect. This very probably contributed to impress our correspondent with the thought that the three bristles which are extruded by the male are a formidable three-pronged sting.
Another fact which I do not see alluded to by any author, is the fetid carrion-like odor which some of these Asilus flies exhale. I noticed this odor in the Erax rufibarbis which was captured as above related. And in these Nebraska specimens, though they have now been dead a fortnight and freely exposed to the air the latter half of that time, this disgusting scent still remains, and so powerful is it thật on two occasions nausea has been produced when they have happened to be left upon the table beside me. As the newly captured fly above mentioned is wholly destitute of this fetor, it may be that it is only at the period of sexual intercourse that it occurs.
These flies are inhuman murderers. They are the savages of the insect world, putting their captives to death with merciless cruelty. Their large eyes divided into such a multitude of facets, probably give them most acute and accurate vision for espying and seizing their prey; and their long stout legs, their bearded and bristly, head, their whole aspect indicates them to be of a predatory and ferocious character. Like the hawk they swoop upon their prey, and grasping it securely between their fore feet they violently bear it away. They have no teeth and jaws wherewith to bite, gnaw and masticate their food, but are furnished instead with an apparatus which answers them equally well for nourishing themselves. It is well known what maddening pain the horse flies occasion to horses and cattle, in wounding them and sucking their blood. These Asilus flies possess similar organs, but larger and more simple in their structure, more firm, stout and powerful. In the horse flies the trunk or proboscis is soft, flexible and sen
BEE-KILLER. ITS HABITS AND DESTRUCTIVENESS. sitive. Here it is hard and destitute of feeling—a large, tapering, hornlike tube, inclosing a sharp lance or spear-pointed tongue to dart out from its end and cut a wound for it to enter, this end, moreover, being fringed and bearded around with stiff bristles to bend backward and thus hold it securely in the wound into which it is crowded. The proboscis of the horse flies is tormenting. but this of the Asilus flies is torturing. That .presses its soft cushion-like lips to the wound to suck the blood from it; this crowds its hard prickly knob into the wound to pump the juices therefrom. It is said these Asilus flies sometimes attack cattle and horses, but other writers disbelieve this. Should any of our Nebraska friends see one of these bee-killers alighting upon and actually wounding horses or cattle, we hope they will inform us of the fact, that this mooted point may be definitely settled. Certain it is that thesc fies nourish themselves principally upon other insects, attacking all that they are sufficiently large and strong to overpower. Even the hard crustaceous shell with which the beetles are covered fails to protect them from the butchery of these barbarians. And formidably as the bee is equipped for punishing any intruder which ven• tures to molest it, it here finds itself overmatched and its sting powerless against the horny proboscis of its murderer. These flies appear to be particularly prone to attack the boes. Robineau Desvoidy states that he had repeatedly seen the Asilus diadema, a European species somewhat smaller than this of Nebraska, flying with a bee in its hold. But it probably does not relish these more than it does other insects. We presume it to be because it finds them in such abundance, as enables it to make a meal upon them most readily, and with the least exertion, that these Nebraska fies fall upon the bees and the rose bugs. And so large as they are, a single one will require perhaps a hundred bees per day for its nourishment. If these flies are common, therefore, they will inevitably occasion great losses to the bee keepers in that part of our country.
No feasible mode of destroying this fly or protecting the bees from it at present occurs to me. Indeed such an accurate knowledge of the particular habits of this species as we do not at present possess, is necessary, to show in what manner it can be most successfully combatted.
Since the foregoing account was written, Mr. Thompson has favored us with another communication, giving some most interesting observations upon the habits and destructiveness of this insect, which we here append in his own words. He says, My attention was first called to this fly destroying the honey bee by a little boy, a son of D. C. Utty, Esq., of this place. After sending you the specimens I watched its proceedings and habits with much care, and find that, in addition to the honey bee and rose bugs, it devours many other kinds of beetles, bugs and flies, some of which are as large again as itself. It appears to be in the months of June and July that it is abroad upon the wing, destroying the bees. None of them are now (August 2d) to be seen. When in pursuit of its prey it makes quito rapid dashes, always capturing the bee on the wing. When once secured by wrapping its legs about it, pressing it tightly to its own body, it immediately seeks a bush or tall weed, upon which it alights and commences
BEB-KILLER ITS TENACITY OF LIFE. devouring its prey by eating (piercing) a hole into the body and in a short time entirely consuming it (sucking out the fluids and soft internal viscera) and leaving only the hard outer skin or shell of the bee. Upon the ground beneath some favorable perch for the fly near the apiary, hundreds of these shells of bees are found accumulated in a single day-whether the work of one fly or of several I am not able to say. I have just returned from a professional tour through the northern portion of our Territory, taking Nur. sery orders; and in many things this business and the apiary are closely connected. In no case have I found a hive of bees that has thrown off a swarm this season! The dry weather, bad pasture and other reasons were assigned as the cause. But many persons, since they have found this ily at his work of destruction, now believe it to be the cause of the nonswarming of their bees; and I am led to the same opinion. I have only to add further, that this Bee-killer delights in hot, dry weather, and is very invulnerable and tenacious of life. I have observed the honey bee and also the hornet sting it repeatedly, but with no other effect than to cause it to tighten its hold upon them. Once when I forced the assassin to release his prey, he gave me such a wound in the hand as has learned me ever since to be cautious how I interfered with him. He will live an hour with a pin thrust through his body which has been dipped in the solution of Cyanuret of Potassium.