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ENTOMOLOGY.

No. XII. HUMBLE-BEES.—Does the gardener know why his Broad-beans have not produced a fair crop this summer? if not, we can inform him. When the beans were in full flower towards the end of May, my attention was called to the injuries they had sustained in the horticultural gardens from the attacks of bees. More than three-fourths of the blossoms at that time had been perforated on the upper side of the calyx, near the centre or a little towards the base (fig. 2), and likewise through the upper lobe of the flower; and this was the ingenious contrivance of the humble-bees to get at the honey contained in the nectary, and which they effected very readily by nibbling a hole with their strong mandibles (4),* through which they could insert their strong horny proboscis; and this operation necessarily proves a very great detriment to the crop, as the perforated blossoms, with very few exceptions, are not able to perfect their seed-vessels; so that out of knots containing from five to eight flowers, only one or two I observed had escaped the attacks of the bees and would form their pods.

In June, I examined some Horse-beans that were suffering in the same way to a great extent, and it was amusing to witness the investigations which a humble-bee made of the sweet-scented flowers, roving from one stem to another, and alighting with the greatest precision, with its head over the calyx, just putting its proboscis to the aperture, and then departing to survey another. It may be inferred from the instinct of this little animal, that the flowers which were untouched and which it did not perforate were destitute of honey at the time, and that some, at least of the wounded ones, continued to secrete that fluid after they had been tapped; and this opinion is strengthened by a late inspection of the crop, when I found many pods with a rough brown wound near the base, which was distorted and deficient of beans, excepting two or three at some distance from the puncture.

The humble-bees, amounting to thirty-five species, form one of the finest groups of insects in this country, and, from their size and striking colours, are well known by every one; those which I detected sucking the beans, were the Bombus terrestris and B. lucorum of Linnæus; the former is densely clothed with fine hairs, of an intense black colour, with a broad band of bright ochre at the fore part of the thorax; a similar band towards the base of the abdomen, and two or three of the apical segments, are of the same colour, unless bleached by age, when they are often whitish or even pure white; the legs are strong; the feet brownish; the wings are stained with yellow, brownish at the apex, the nervures being pitch-brown. (fig. 3).

Humble-bees form their nests at the roots of trees and amongst loose rubbish, such as heaps of bricks and stones covered with earth, also in cavities of old walls; they are covered with moss, collected in the summer, and are sometimes lined with wax. The comb is formed of oval cocoons, irregularly clustered together, and made of a kind of silk, daubed over with wax; they vary in size and number, sometimes amounting to sixty. In the earliest days of spring, the female humble-bees emerge from their winter quarters where they had hybernated, and collect pollen and honey from the catkins of the willows; later in the season the neuters appear, but the males are not common until the autumn, when the Thistle-flowers afford them an abundant supply of honey, in which they delight and partake of so freely, that these jovial bees are often seen feeling about as if intoxicated, throwing out their legs in a very grotesque manner, and eventually nestling in the soft flowers, fall asleep at the approach of night.

I believe that the hive-bees are accused of participating in the spoliation of the Bean-crops, but there seems to be little doubt that the female humble-bees are the parties who first wound the calyx in the manner described; and they will travel a long distance, I expect, in search of food. I am convinced that, at least, four-fifths of the crops I have inspected are destroyed this season; it would, therefore, be a very desirable object with the Bean-grower to avoid such a loss, and no better means could be adopted than to destroy the humble-bees' nests at the end of summer, and employ children to catch and kill the females in the Bean-fields as soon as the first blossoms have expanded.

It is probable that many other plants suffer from the same cause, for I am informed that the calyx and flowers of the Azalea are often punctured by the bees; and I

* For other parts of the mouth, &c., see Curtis's Brit. Ent., Pl. 564.

have heard of the Honeysuckle being subject to similar injuries.

It may be remarked, that all the leaves of the Broad-beans of the crop first alluded to, had the edges indented, and they exhibited the same appearance last week, but I am ignorant of the animal that has caused this strange appearance; it is possible that it may be the work of woodlice or of earwigs, and I shall be glad if any one will confirm or set me right on the subject; for as it is presumed to be a nocturnal operation, I have not the opportunity of settling the question.—Ruricola.