The MALE differs in having the antennæ longer than the thorax, filiform, but with their several joints curved, the curvature increasing towards the terminal joints, the integument of the whole of the flagellum consisting of a congeries of minute hexagons, the edges of which are all raised, and the whole resembling shagreen; the legs have the usual sexual slighter and extended development, and are necessarily less setose; it is also deficient in the transverse whitish bands of decumbent hair upon the abdomen, which is more densely pubescent on the first and second segments; and the four terminal joints of the posterior tarsi are conterminous with their plantæ.
NATIVE SPECIES.
1. longicornis, Linnæus. 6-7 lines. ([Plate VI.] fig. 2 ♂♀.)
longicornis, Kirby.
GENERAL OBSERVATIONS.
This genus derives its name from the great length of the antennæ in the male,—εὖ, good or great, κέρας, horn. The name of the genus is usually given from some female characteristic, or from a peculiarity common to both sexes, or irrespective of any direct application, but here we find it deduced from a feature exclusively masculine. Instances of the first class we see in Colletes, Halictus, Andrena, Dasypoda, Panurgus, Saropoda, Ceratina, Cœlioxys, Chelostoma, Heriades, Anthocopa, and Apathus; of the second class we have Prosopis, Sphecodes, Macropis, Anthophora, Nomada, Melecta, perhaps Epeolus, according to Latreille’s idea, Stelis, Anthidium, Osmia, and Bombus; the third class comprises in our series merely Cilissa, and in this series the male characteristics that have suggested the name are just as few, being limited to the present genus. But the males among the bees exhibit in many cases strong and striking peculiarities which distinguish them from their partners. Exclusively of the general distinction expressed in their organic difference by the possession of one additional joint to the antennæ and one more segment to the abdomen than is exhibited in the females, we find in many cases in these two parts of their structure very marked singularities. Great sexual differences in the length of the antennæ are not restricted to the present genus; in fact, in most of the genera, this is the first striking feature, but which becomes conspicuously so in some species of Sphecodes, in most of the Halicti, in some Nomadæ, in Chelostoma, Osmia, Apathus, and Bombus. In Eucera and Sphecodes, each joint of the flagellum is slightly curved, and in the former the surface of those joints appears compounded of hexagons. In Chelostoma the antennæ, besides being longer than in the female, are also very much slighter and slightly compressed, and have a structure capable of curling upon itself; in the female of this genus the organ is clavate; and in Osmia, besides their length, in one species the male has a fringe of hair attached to one side along the whole of the organ. In other cases, where the antennæ are not remarkably longer in the male they have extra development by becoming thicker, as in Melecta; and in Megachile the terminal joint of their antennæ is laterally dilated and compressed. In scarcely any case are they geniculated at the scape in the male, as they are in the female. The other genera with clavate antennæ have the same structure in both sexes, as in Panurgus and Ceratina. Remarkable peculiarities in the terminal ventral segment or segments of the male may be found most conspicuously developed in Halictus, Cœlioxys, Anthidium, Chelostoma, Heriades, Osmia, Apathus, Bombus, and Apis. In Cœlioxys and Anthidium, and some of the Osmiæ, this sex is further furnished with a series of projecting spines, processes, or serrations at the apex of the terminal dorsal segment. In Chelostoma, the ventral structure of the male is very singular, the apex being adapted to a mucro at the base which permits the insect to curl up this portion of the body similarly to its antennæ, the furcated extremity of the abdomen fitting, when thus folded, upon the mucro. It is as well to draw observation to these peculiarities, which give additional interest to the study of the group.
The genus Eucera appears in May and June. In some parts they are found in large colonies; although I have seen them abundant I never found them in this gregarious condition, and I have usually discovered them frequenting loamy and sandy soils; they burrow a cell six or eight inches deep, form an oval chamber at its extremity, which as well as the sides of the cylinder leading to it they make extremely smooth, and by some process prevent its absorbing the mixture of honey and pollen which they store for the supply of the larva, and each contains but one young one. These, having full fed, lie in a dormant state throughout the winter and do not change into pupæ until mid-spring, and speedily transform into the imago, which, until fully matured, is closely in every part and limb covered with a thin silky pellicle, wherein it lies as in a shroud, but at its appointed time, regulated by some influence of which we have no cognizance, active life becomes developed, it then casts off its envelope and comes forth to revel in the sunshine, in close companionship with a partner which its instinct promptly teaches it to find. The largest of our native Nomadæ is its parasite the N. sexcincta, and which seems wholly restricted to it, but which is often even rare in places where the Eucera abounds. The female, like those of the rest of the bees, is no time-waster, but flies steadily to and fro in her occupation of provisioning her nest, and the male often accompanies her in these expeditions, gallantly winging about with extreme velocity as if to divert his sedulous companion in the fatigue of her toil, by his evolutions and his music, which is very sonorous. And on a fine May day it is extremely pleasant in a picturesque situation to sit and watch the operations of these very active insects. In their recent state, when just evolved from the nidus, they are very elegant, being covered with a close silky down, which labour and exposure soon abrades. It is said that this bee deserts her nest when she finds the stranger’s egg deposited on the provender laid up in store, or when she meets with the Nomada within, which sometimes lays two eggs in one cell. To this she does not deliver battle, as does the Anthophora to Melecta, but patiently vacates the nest, leaving it to the service of the parasite, which is also supposed to close it herself, having been caught with clay encrusted upon her posterior legs. For the accuracy of this supposition I cannot vouch, never having observed the circumstance, nor have I seen reason to abandon the idea that the parasite has no instinct for labour of any kind,—the presence of the clay being, I expect, merely accidental, for it is notorious that these insects have an overruling predilection for keeping themselves extremely clean.
†† With three submarginal cells to the wings.
Genus 11. Anthophora, Latreille.