David Sharp

“ When it discovers a tarantula it flies "in circles in the air, around its victim. The spider, as if knowing its fate, stands up and makes a show of fighting, but the resistance is very feeble and of no avail. The spider's foe soon discovers a favourable moment and darts upon the tarantula, whom it wounds with its sting, and again commences flying in circles." The natural retreat of this huge spider, Mygale hentzii, is in holes in the ground, and this account does not inform us whether the spider allows itself to be overcome when in its nest, or is only attacked when out of its retreat. ”

“ There is not only usually a difference between the sexes in this respect, but also extreme variation within the limits of the same sex, more especially in the case of the males and workers; there is also an astonishing difference in the size of individuals. These variations are carried to such an extent that it is almost impossible to discriminate all the varieties of a species by inspection of the superficial characters. The structures peculiar to the male, as well as the sting of the female, enable the species to be determined with tolerable certainty. ”

“ But having dubbed ourselves the higher animals, we ascribe the eagerness of the solitary wasp to impulse or instinct, and we exterminate their numerous species from the face of the earth for ever, without even seeking to make a prior acquaintance with them. ”

“ We think it possible, however, that a knowledge of the mode of feeding of this larva may show that a more perfect nutrition is obtained from a well-constructed cylinder, and if so this would to a slight extent satisfy our longing for explanation, though throwing no light whatever on the physiology or psychology of the artificer, and leaving us hopelessly perplexed as to why a beetle in ages long gone by should or could adopt a mode of life that by long processes of evolution should, after enormous difficulties have been overcome, attain the perfection we admire. ”

“ Why then should they attack the creatures? Provided the parasites do not interfere in any unmannerly way with the hosts and their work, there is no reason why the latter should resent their presence. The wild bee that seals up its cell when it has laid an egg therein, and then leaves it for ever, has no conception of the form of its progeny; never in the history of the race of the Andrena has a larva seen a perfect insect and survived thereafter, never has a perfect Insect seen a larva. ”

“ In ants the phenomena of the kind we are alluding to are very much more complex. There are no solitary ants; associations are the rule (we shall see there are one or two cases in which the association is with individuals of other species) . In correlation with great proclivity to socialism we find an extraordinary increase in the variety of the forms of which species are made up. In addition to the male and female individuals of which the species of Insects usually consist, there are in ants workers of various kinds, and soldiers, all of which are modified infertile females. ”

“ The males of some species fight; they do not, however, wound their opponent, but merely frighten him away. In Eupsalis it appears that the rostrum of the female is apt to become fixed in the wood during her boring operations; and the male then extricates her by pressing his heavy prosternum against the tip of her abdomen; the stout forelegs of the female serve as a fulcrum and her long body as a lever, so that the effort of the male, exerted at one extremity of the body of the female, produces the required result at the other end of her body. ”

“ It is therefore no wonder that flies are not popular, and that few are willing to study them, or to collect them for observation. Nevertheless, Diptera have considerable claims to be classed as actually the highest of Insects physiologically, for it is certainly in them that the processes of a complete life-history are carried on with the greatest rapidity and that the phenomena of metamorphosis have been most perfected. A maggot, hatching from an egg, is able to grow with such rapidity that the work of its life in this respect is completed in a few days ”

“ A very large number of bees are parasitic in their habits, laying an egg, or sometimes more than one, in the cell of a working bee of some species other than their own; in such cases the resulting larvae eat and grow more quickly than the progeny of the host bee, and so cause it to die of starvation. It has been observed that some of these parasitic larvae, after eating all the store of food, then devour the larva they have robbed. In other cases it is possible that the first care of the parasitic larva, after hatching, is to eat the rival egg. ”

“ The male is an ordinary winged ant, and is so like that sex of the Leptothorax, that Adlerz had failed to distinguish the two before he reared them. The females are apterous, and in fact like the workers. It would perhaps be more correct to say that the workers of this species vary greatly but never become winged; some of them have ocelli and a structure of the thorax more or less similar to that of winged females, though none have been found with wings. Certain of these females possess a receptaculum seminis, and Adlerz treats this as the true distinction between female and worker. ”

“ The home must be, for the bee, in the proper situation, or it is not recognised as the desired object. Thus we are confronted with the strange fact that the very bee that is able to return to its nest from a distance of four kilometres can no longer recognise it when removed only a yard from the original position. This extraordinary condition of the memory of the Insect is almost inconceivable by us. That the bee should accurately recognise the spot, but that it should not recognise the cell it had itself just formed and half-filled with honey-paste, seems to us almost incredible ”

“ It was found by transferring ants from one hill to another that no hostility whatever existed between the denizens of different hills; the specimens placed on a strange hill entered it without the least hesitation. Its habits differ in some particulars from those of its European congener; the North American Insect does not close the formicary at night, and the inquilines found in its nest are very different from those that live with F. rufa in Europe. Whether the typical wood-ant occurs in North America is doubtful, but there are races there that doubtless belong to the species. ”

“ No Insects are more familiar to us than ants; in warm countries some of them even invade the habitations of man, or establish their communities in immediate proximity to his dwellings. Their industry and pertinacity have, even in remote ages, attracted the attention and admiration of serious men; some of whom—we need scarcely mention Solomon as amongst them—have not hesitated to point out these little creatures as worthy of imitation by that most self-complacent of all the species of animals, Homo sapiens. ”

“ In many cases the shape of the body is so very different from the normal that the disposition of the organs of life in the interior of the body must be materially affected. In some genera, such as Andrenimorpha, the form, colour and attitude of the body and some of the limbs are plainly similar to Hymenoptera. These Insects have a highly-developed frenulum, retinaculum, and proboscis; bipectinate antennae in the male, a complex organ at the base of the abdomen on each side, and are in fact highly-developed forms, except perhaps as regards the structures in connexion with flight. ”

“ The killing of superfluous queens is also probably a phenomenon of captivity, for it varies even now in accordance with the numbers of the colony. It is interesting to notice that in confinement when a swarm goes from the hive it is the old queen that accompanies it, and this swarm as a rule settles down near the old hive, so that the queen-bee being already fertilised, the new swarm and its subsequent increase are nothing but a division of the old hive, the total products of the two having but a single father and mother. ”

“ The social habits are in many species only inferred, and with greater knowledge will probably prove fallacious as a guide to classification; indeed we have already said that in the genus Vespa—perhaps the most perfectly social of all the wasps—there is one species that has no worker, and that lives, it is supposed, as a parasite, in the nests of its congeners. ”

“ The smaller, grey Haematopota, is known to every one who has walked in woods or meadows in the summer, as it alights quietly on the hands or neck and bites one without his having previously been made aware of its presence. ”

“ The females in many groups of Dytiscidae bear on the upper surface of the body a peculiar sculpture of various kinds, the exact use of which is unknown; in many species there are two forms of the female, one possessing this peculiar sculpture, the other nearly, or quite, without it. The larvae of Dytiscidae differ from those of Carabidae chiefly by the structure of the mouth and of the abdomen. They are excessively rapacious, and are indeed almost constantly engaged in sucking the juices of soft and small aquatic animals, by no means excluding their own kind. ”

“ The difference in colour of the sexes is very remarkable, red or yellow predominating in the female, intense black in the male; and it is a curious fact that the same sexual distinction of colour reappears in various parts of the world—England, America, India, and New Zealand; moreover, this occurs in genera that are by no means closely allied, although allied species frequently have concolorous sexes. The eyes of the males are well worth study, there being a very large upper portion, and, abruptly separated from this, a smaller, differently faceted lower portion, practically a separate eye ”

“ In America numerous cases are known of Oestrid larvae being taken from the body of man, but information about them is very scanty. It appears, however, that there are at least four species, one of which, Dermatobia noxialis, is known as a fly as well as a larva. Whether any of these are peculiar to man is uncertain. [442] There are several larvae of Muscidae that have similar habits to the Oestridae; hence the statements that exist as to larvae being found in birds and reptiles cannot be considered to apply to members of the latter family until the larvae have been studied by an expert. ”

“ Observation has revealed most remarkable phenomena in the lives of these Insects. Indeed, we can scarcely avoid the conclusion that they have acquired in many respects the art of living together in societies more perfectly than our own species has, and that they have anticipated us in the acquisition of some of the industries and arts that greatly facilitate social life. The lives of individual ants extend over a considerable number of years—in the case of certain species at any rate—so that the competence of the individual may be developed to a considerable extent by exercise ”

“ The cells in which the young of the Psithyrus are hatched are very much larger than those of the Bombus, and, it may therefore be presumed, are formed by the Psithyrus itself, for it can scarcely be supposed that the Bombus carries its complaisance so far as to construct a cell specially adapted to the superior stature of its uninvited boarder. When a Psithyrus has been for some time a regular inhabitant of a nest, the Bombus take its return home from time to time as a matter of course, displaying no emotion whatever at its entry. ”

“ The mode of hunting has been described by Ferton; the wasp hovers over one of the ant-paths at a distance of a few millimetres only above the surface, and when an ant that is considered suitable passes, the Fertonius pounces on it, stings it, and carries it off to the burrow; forty or fifty ants are accumulated in a cell, the egg is laid in the heap of victims about one-third of the depth from the bottom; the resulting larva sucks the ants one by one, by attaching itself to the thorax behind the first pair of legs. ”

“ We all know that the Flea is so flat, or compressed sideways, that it does not mind the most severe squeeze. This condition is almost peculiar to it; a great flattening of the body is common in Insects—as is seen in another annoying Insect, the bed-bug—but the compression, in the flea, is in the reverse direction. In other respects the external anatomy of the flea shows several peculiarities, the morphological import of which has not yet been elucidated. ”

“ The species of the genus Atta (usually styled Oecodoma) are the formidable leaf-cutting ants of America. They occur in enormous colonies in certain places, and will in a short time completely strip a tree of its leaves. As they appear to prefer trees of a useful kind, especially those planted by man, their ravages are often of the most serious nature. The natives, feeling it hopeless to contend with these Insect hordes, only too frequently abandon all attempts to cultivate the trees and vegetables the Insects are fond of. ”

“ Wasmann has pointed out that the ants'-nest beetle, Lomechusa, takes much food from the ants, and itself destroys their young, and that in nests where Lomechusa is abundant a large percentage of ergatogynous forms of the ants are produced. He attributes this to the fact that the destruction of the larvae of the ant by the beetle brings into play the instinct of the ants, which seek to atone for the destruction by endeavouring to produce an increased number of fertile forms; many ergatogynous individuals being the result. ”

“ Thus we have seen that in Aphidae generations of imperfect individuals are produced with rapidity, while the individual is not directly very prolific. In Coccidae the reverse is the case—the generations are usually similar to one another; they do not, as a rule, follow with rapidity, and the female is usually very prolific, thousands of young being sometimes produced by a single individual. The extraordinary polymorphism of the species of Aphidae is not exhibited by Coccidae, though, contrary to what we find in Aphidae, the males and females are usually excessively different. ”

“ The metamorphosis is also peculiar; the larva does not differ greatly in appearance from the adult, and has similar mouth-organs and food-habits. The wings are developed outside the body at the sides, and appear first, according to Heeger, after the third moult. The nymph-condition is like that of a pupa inasmuch as no nourishment is taken, and the parts of the body are enclosed in a skin: in some species there is power of movement to a slight degree, but other species are quite motionless. In some cases the body is entirely bright red, though subsequently there is no trace of this colour. ”

“ How necessary it is to these Insects to possess this faculty of finding their nests will be understood when we recall that the Bembex does not provision its nest once and for all, but supplies the young at first with only insufficient food, and has therefore to return at daily, or other intervals, with a fresh store of provisions. The burrow is made in the sand by means of the fore-legs; these work with such rapidity and skill that a constant stream of sand flows out behind the Insect while it is engaged in the act of excavation. ”

“ Though much neglected by collectors and naturalists, some 1500 species of the family Malacodermidae have been detected. We have about 50 in Britain, and many of them are amongst the most widely distributed and abundant of our native Insects. Thus, however near they may be to the primitive condition of Coleoptera, it is highly probable that they will continue to exist alongside of the primitive Cockroaches and Aptera, long after the more highly endowed forms of Insect-life have been extinguished wholesale by the operations of mankind on the face of the earth. ”