Manual of the apiary

by Albert John Cook

THE SOUTHERN BEE-KILLERS.

Mallophora orcina and Mallophora bomboides.

I have received from several of our enterprising bee-keepers of the South—Tennessee, Georgia and Florida—the above insects, with the information that they dart forth from some convenient perch, and with swift and sure aim, grasp a bee, bear it to some bush, when they leisurely suck out all but the mere crust, and cast away the remains. The bee which is thus victimized, is readily known by the small hole in the back, through which the juices were pumped out.

The insects plainly belong to the family Asilidæ, the same that includes the Missouri bee-killer, Asilus Missouriensis, the Nebraska bee-killer, Promachus bastardi, and other predatory insects, several of which, I regret to say, have the same evil habit of killing and devouring our friends of the hive.

The characters of this family, as given by Loew, one of the greatest authorities on Diptera, or two-winged flies, are prolonged basal cells of the wings, third longitudinal vein bifurcate, third joint of antenna simple, under lip forming a horny sheath, empodium, a projection below and beneath the claws ([Fig, 131, c]), a horny bristle.

Fig. 128.		Fig. 131.

The insects in question belong to Loew's third group, Asilina, as the antennæ end in a bristle ([Fig, 128]), while the second longitudinal vein of the wing ([Fig, 129, b]) runs into the first ([Fig, 129, a]).

The genus is Mallophora. The venation of the wings much resembles that of the genus Promachus, the same that contains the Nebraska bee-killer, though the form of these insects is very different. The Nebraska bee-killer is long and slim like the Asilus Missouriensis (see [Fig, 108]), while the one in question is much like the neuter bumble-bee in form.

In Mallophora and Promachus, the venation is as represented in [Fig, 129], where, as will be seen, the second vein ([Fig, 129, b]) forks, while in the genus Asilus ([Fig, 130]) the third vein is forked, though in all three genera the third joint of the antennæ ([Fig, 128]) ends in a prolonged bristle.

One of the most common of these pests, which I am informed by Dr. Hagen, is Mallophora orcina, Wied, ([Fig, 126]) is one inch long, and expands one and three-fourths inches ([Fig, 127]). The head ([Fig, 128]) is broad, the eyes black and prominent, the antennæ three-jointed, the last joint terminating in a bristle, while the beak is very large, strong, and like the eyes and antennæ, coal black. This is mostly concealed by the light yellow hairs, which are crowded thick about the mouth and between the eyes.

Fig. 129,

The thorax is prominent and thickly set with light yellow hairs. The abdomen is narrow, tapering, and covered with yellow hairs except the tip, which is black. Beneath, the insect is clear black, though there are scattering hairs of a grayish yellow color on the black legs. The pulvilli, or feet pads ([Fig, 131, b]) are two in number, bright yellow in color, surmounted by strong black claws ([Fig. 131, a]), while below and between is the sharp spine ([Fig, 131, c]), technically known as the empodium.

I cannot give the distinctions which mark the sexes, nor can I throw any light upon the larval condition of the insect.

The habits of the flies are interesting, if not to our liking. Their flight is like the wind, and perched near the hive, they rush upon the unwary bee returning to the hive with its full load of nectar, and grasping it with their hard strong legs, they bear it to some perch near by, when they pierce the crust, suck out the juices, and drop the carcass, and are then ready to repeat the operation. A hole in the bee shows the cause of its sudden taking off. The eviscerated bee is not always killed at once by this rude onslaught, but often can crawl some distance away from where it falls, before it expires.

Another insect nearly as common is the Mallophora bomboides, Wied. This fly might be called a larger edition of the one just described, as in form, habits and appearance, it closely resembles the other. It belongs to the same genus, possessing all the generic characters already pointed out. It is very difficult to capture them, as they are so quick and active.

Fig. 130.

This fly is one and five-sixteenths inches long, and expands two and a half inches. The head and thorax are much as in the other species. The wings are very long and strong, and, as in the other species, are of a smoky brown color. The abdomen is short, pointed, concave from side to side on the tinder surface, while the grayish yellow hairs are abundant on the legs and whole under portion of the body. The color is a lighter yellow than in the other species. These insects are powerfully built, and if they become numerous, must prove a formidable enemy to the bees.

Another insect very common and destructive in Georgia, though it closely resembles the two just described, is of a different genus. It is the Laphria thoracica of Fabricius. In this genus the third vein is forked, and the third joint of the antenna is without the bristle, though it is elongated and tapering. The insect is black, with yellow hair covering the upper surface of the thorax. The abdomen is wholly black both above and below, though the legs have yellow hairs on the femurs and tibia. This insect belongs to the same family as the others, and has the same habits. It is found North as well as South.