CHAPTER IVNOTICE OF THE MORE CONSPICUOUS FOREIGN GENERA OF BEES.
Seeingthus the wide and almost universal distribution of many of our own genera, we might be induced to ask whether this could not suffice, by the impetus which more genial climates give to the multiplication of individuals, to meet all the exigencies of the most favoured regions of the vegetable kingdom. This is not so. There seems scarcely a limit to the exuberance wherein nature revels in the production of variations of form. The splendour, elegance, and infinite variety which she displays in her floral beauties in the most luxuriant climates, find rivalry as well in the multitude as in the magnificence of the insects which she has allied with them as the indispensable promoters of their perpetuation. How otherwise than through some of the insects we shall mention could tropicalLabiatæand the tubulated flowers of theRubiaceæ, etc. be fertilized? The reader will therefore, I trust, welcome an acquaintance with some of the most conspicuous of the group of bees produced by tropical countries, although the main object of this treatise is to exhibit the attractions of “our native bees.”
I will but superficially and rapidly glance at themore distinguished exotic genera and species, as supplementary to the preceding notice of the geographical range of those which are indigenous with us.
How our own species reached us is a subject which has at present eluded all satisfactory determination. For its solution we must await the further discoveries of geology; at present we can only attribute their advent here to the same causes which are common to the production of all our groups of both the animal and the vegetable kingdoms.
Knowing how affluent tropical and sub-tropical countries are in the variety, size, and number of the forms, as well as in the splendour of their plants and vertebrated animals, we may fairly expect as gorgeous a richness in the insects they produce. Nor shall we be disappointed, for the imperial magnificence of theirLepidopteraandColeopteraguarantees an equivalent brilliancy in the other orders of insects, and which is fully confirmed by the harmonious splendour of their bees.
They thus put forward claims to attention and must excite curiosity by their beauty and size, which the comparative smallness of our own, and the usual dulness of their colours do not possess. The latter only repay notice upon close investigation, but they then as amply reward all labour bestowed upon them by the mental recreation they yield, as their more gaudy exotic rivals. The former present themselves obtrusively and exact notice, whereas ours meekly solicit it by their humble but solid allurements. Here, as well as there, we behold the works of a mighty hand and of an immeasurable intelligence.
The bees throughout the world, as known collectively to the richest cabinets, number about two thousand species. This host, in itself numerically so large, solicitsattention, for it is opposed to the economy of nature that there should exist any without functions of essential usefulness, making them important elements in her harmonious order and necessary to her due course, irrespective of the instruction to be derived from the study of the manifold varieties of structure, which unquestionably point to distinguishing peculiarities of habits.
In the true bees the division of theDasygasterspresents the fewest differing generic forms: theNudipedesandScopulipedesexhibit more numerous varieties, the preponderance being in favour of the pollen-collecting bees (the latter), although the cuckoo-bees (theNudipedes) are very abundant, and takenen masse, are certainly the handsomest. If it be absolutely the case that there are no parasites amongst theAndrenidæ, this subfamily will add very largely to the exotic pollinigerous majority, which thereby becomes extensively subservient to the fruition of the vegetable kingdom.
Those bees which are exclusively inter- or sub-tropical, seem furnished with larger capacities for fulfilling the special mission to which the family is appointed. Their pollinigerous and honey-collecting organs are peculiarly adapted both to the structure and luxuriance of the superb vegetation of those regions, and to which they seem distinctly limited. But that they are not considered equivalent to the entire demand of the profuse bloom everywhere abounding, may be concluded from the tropical range and distribution of many of our northern forms. Thus, whilst the flora of those climates is strictly circumscribed in its diffusion, its fauna, distinctly in the class of insects, and especially in the family of bees, is very considerably less limited, in extension.
The exotic genera of bees which are peculiarly noticeable,either from splendour, size, or remarkable eccentricities of structure, are numerous. Tropical and sub-tropical regions of course abound with them, in individuals, in species, and in genera; and when we reflect upon the riches of the flora of those countries, which is perpetuated mainly by the agency of insects, amongst which, in fulfilling this indispensable demand, bees, as I have reiterated, are pre-eminently conspicuous, we shall not even wonder that their number, although excessive in the extreme, is considerably aided, in many cases, in the performance of this task, by peculiarities of structure. Thus, the splendid Brazilian genusEuglossa, although not conspicuous for size, is remarkably so for the enormous development of its posterior tibiæ, which form very large triangles, compared with the size of the insect, deeply hollowed for the conveyance of pollen. Its tongue also, from the length of which the genus derives its name, is, when extended, more than twice the length of the body, and with which it is enabled to reach the nectarium, seated within the depths of the longest tubes of flowers. Other exotic bees, further to aid them in collecting pollen, in addition to the dense brushes with which their posterior legs are variously covered, have each individual hair of these thick brushes considerably thickened by hairs given off laterally, and in some cases these again ramify. Sometimes, in variation, the simple, single hairs have a spiral curve, which almost equally enlarges the activity of their operation. This is also the case with two very hairy-legged genera of our native bees, proximately allied to each other in the methodical arrangement,DasypodaandPanurgus, the hair of whose posterior legs have this spiral twist. The most hairy-legged exotic bees are essentially the generaCentrisandXylocopa. Of the habits of the former we know nothing, but those of the latter we are intimately acquainted with, through the elaborate descriptions given by Réaumur and the Rev. L. Guilding, the latter of whom made his observations upon a species found in the island of St. Vincent’s, in the West Indies. This last genus exhibits in some of its species the giants among the bees, and one is especially so, a native of India, theXylocopa latipes, which is an inch and a quarter long, and more than three inches in the expansion of its black, acute wings; and it is also noticeable from the anterior tarsus in the male being greatly dilated and white, the bee itself being intensely black, and which in this same sex has enormous eyes united at the vertex, as in the maleApis, or drone. In this genus, as in many other genera of bees, there is often a great discrepancy in the appearance of the sexes, they being so totally dissimilar that no scientific skill has hitherto been able to discover a clue for uniting together correctly, by scientific process merely, the sexes of a species; thence the numbers of the species in such genera are unduly augmented beyond their natural limits, from the fact of observation having neglected to associate the legitimate partners.
In some of our native genera this same difficulty existed, which, however, is gradually diminishing as the authentic sexes are slowly discovered.
Exotic bees exhibit also a peculiarity I had occasion to observe before, in reference to our own bees, amounting perhaps to a law, viz the more highly-coloured condition of the parasite, for we find all the parasitical bees of those latitudes, usually gorgeously arrayed in metallic splendour, as instanced inAglaë,Mesonychia,Mesocheira, etc., andMelissoda(myIschnocera, in Lardner), is remarkablyconspicuous for its long and delicately slender antennæ in the male, each joint of which is nodose at its extremity.
The widely-distributedNomiaseems to abound chiefly in India. It, although neither gay nor large, has, in its males, a distinguishing form of the posterior tibiæ, which is greatly incrassated or thickened; a peculiarity of structure found also in some other genera ofHymenoptera, and in several genera of theDiptera, giving the insects which have it a remarkable gait.
The singularly anomalous distortion of these posterior legs is conspicuous also in the genusAncylosceles, which is named in allusion to it.
Another remarkable peculiarity is to be observed in the above genus,Mesocheira, as likewise in the superbAcanthopus, both of which genera have the spur of the intermediate leg palmated at the extremity, and the latter genus is further distinguished by its large size and splendid development, and by having the fifth joint of the tarsus of the posterior legs longer than the three preceding united, and covered with a pollinigerous brush as dense as that of the elongate first joint of the same limb.
But the foreign genera which will be most interesting to the reader will, I expect, be those ofTrigonaandMellipona, which, in many peculiarities, seem abortiveApes. They seem nature’s first endeavour to constructApis, for they have an apparently imperfect neuration of the wing, in which the external submarginal cell is unfinished. Their only separating distinction from each other is the difference in their mandibles, which inMelliponaare broad and edentate, whereas inTrigonathey are also broad but denticulated. InApisthese organs are merely irregularly enlarged at the extremity, andhollowed within, rather like a spoon, which structure would of course imply a difference of economy.
A further characteristic of these genera, and in which they participate withApis, is the deficiency of spurs to the posterior tibiæ, which separates them from all other genera of bees, as also fromBombus, which has two, yet with which, in point of their economy, they more closely assimilate than withApis. They are the South American and Australian indigenous representatives of the genusApis, and are found likewise in Java and Sumatra, and in some of the larger and extreme islands of the Indian Archipelago, thus also similarly in countries where marsupial animals occur. LikeApis, they are social in their habits; but their neuters only are as yet known, neither males nor females having been described. They are reputed to be stingless, and to make honey and wax in enormous quantities. The combs inMelliponaare attached either to the branches of trees or are suspended from them, but how they are enveloped for security is not reported, but sometimes, likeApis, they construct them within hollow trees and in the cavities of rocks, as inTrigona, in like manner asApisdoes in its natural state. Their communities are not so large as those of the hive bee, and the cells of their combs are less perfectly hexagonal, the wax being expended upon them in denser quantities, whereas the hive bee is exceedingly parsimonious in the use of this material, a circumstance arising possibly from the different and more difficult mode the latter have of obtaining it. In the latter it is a secretion; but these exotic genera possibly collect their wax ready-made by the exudation of plants, and, thus, having more readily obtained it, they are more lavish in its use.
Early travellers and historians describe many kinds of honey made by these bees, native to the South American continent, but they report nothing of the peculiarities of the social economy of these insects, nor whether they are as closely allied in this respect toApis, as they are in the collection of honey and wax.
To enter into further detail relative to them would be beyond the province of this work, and I have only given this extremely superficial and brief notice of foreign genera, to show what multitudes of others of this interesting family await admiration and study, when some proficiency has been acquired in the knowledge of our own.