True Tales of the Insects

• Or only the very slightest rudiments of these.

are minute, unjointed, scarcely visible to the naked eye; but the feet, though very short and thick, are well articulated. It is this structure of the legs which at once distinguishes this imago from the larva; in this respect also it differs from the female of Oikefiats kirbii (see Fig. 40). Having filled the bottom of their puparium with their ova, packed in the down rubbed from their own body, these females do not long survive. The moth is then literally nothing but thin skin. Reduced to a shrivelled, dried, and scarcely animated morsel of this matter, she either presses herself through the opening of the case, or, exhausted, the last feeble flicker of life burnt out, expires within.

CHAPTER XI.

THE HAWK MOTHS (SPHINGID^.).

Few moths are so attractive to lepidopterists, indeed, to all lovers of Nature, as the Sphingidce, or Hawk Moths, partly from the beauty of the specimens. This is an extensive group, and its members, if not surpassing every other family of Heterocera in size, in their speed and indefatigable flight are unequalled.

Leading Characteristics of this Favourite Grotip.

They are a highly organized and specialized assemblage. A plump, robust, yet, as a rule, a graceful body, an usually long, conic, cylindrical abdomen, and pris-said to be their leadingmatic antennse—these may be characteristics; and generally the wings are comparatively small and narrow, the forewings extending far beyond the hind pair, and rather pointed; the tongue, though variable, is often strong and long, much exceeding the length of the insect itself, but is sometimes obsolete. In habits they are diurnal or crepuscular, some flying in

in the earlybrilliant sunshine, and others—the majority-evening, in the twilight and just at dusk; and certain species are nocturnal and fly to light.

The larvse are as readilv distino-uished as the imaoros. Conspicuous, green in colour, hairless, and smooth, many are furnished with a prominent rigid spine near the tail called the caudal horn, which is sometimes lost in the later stages and then replaced by a shining lenticular tubercle. At rest, they have a remarkable fashion of elevating- the head and thoracic seofments, and curving them somewhat in sigmoidal shape, while they support themselves by their four or six hind legs, in which posture they remain for hours together, immovably fixed; and it is supposed that this attitude, giving them a fancied resemblance to the Egyptian Sphinx, prompted the name that Linnaeus bestowed. They pass a solitary existence on trees, shrubs, or low plants, and suffer much from Ichneumonidae, the check that alone prevents some species from becoming very injurious. When full-grown they transform above ground in an imperfect cocoon among leaves, or go underground and pupate in a cell.

MacroglossincE.

Within this family six sub-families are included, and the marvellously specialized condition of some of their

Structural characters is brimful of interest. Most of the ?kIacroglossince bear a complete resemblance to humming-

Fu;. 41.^A loni^ proboscis [Cocytius cluciilius).

birds, due to their large, expansile tuft of hair-scales at the extremity of the abdomen, and their custom of

hovering over flowers while sucking the nectar with their long probosces. That these insects really are birds the uninitiated determinedly believe. The natives of the Amazons, as Bates relates, think that the moth changes into the bird, just as the caterpillar changes to the moth; Bates himself several times shot Acllopos titan in mistake for a humming-bird, so close is the resemblance between them on the wing. The Bee Hawks (Hemaris) have transparent wings, the clear spaces on emergence from the pupa being thinly spread with glittering scales, which fall on the first occasion of lliorht. Durinor the hottest hours of bright sunny days they make their appearance among the blossoms and regale on their sweets, probably like all the Macroglossinse with entire wings, such as Lepisesia; but those with angulated wings fly also in the dusk of evenincr. Genera of the followinor tribe are likewise taken in the day. Because of this diurnal habit, and the general idea that it is the most specialized group, entomologists usually place the Macroglossinae at the head of the great series Sphingidae.

CheerocampiiKS and AmbtUicincE.

To the peculiar tapering, often retractile, form of the larva, the Choerocampinse, the so-called Elephant Hawks,

owe both their English and Greek appellations; Choerocampa, the name of the typical genus, means Hog caterpillar. These moths are chiefly remarkable for their power of swift and long-sustained flight. The whole sub-family throughout shows a tendency to bright colours and distinct shades and bands in wing maculation. The abdomen is rarely banded, and there are few sober grey forms represented; on the contrary, particularly in America, some are of a most beautiful and graceful description. Certain genera, as in the Ambulicinae, have the anal segment of the abdomen in the males expanded laterally, an aspect approaching that of Macroglossinse in

this respect.

Sphingincr.

When we turn to the Sphinginse, we find these, as a rule, sober grey or brown, the usually moderately narrow and pointed wings of even outer margin, not sinuate or angulated as in the Choerocampinae. For the broad shades or bands of the latter, we have here a maculation consisting either of simple, undulated, transverse lines, or of longitudinal, interspacial dashes. Sometimes we get a mottled surface of grey and black without distinct pattern; the abdomen, too, is almost universally banded or spotted; and by these peculiarities in marking, and

the wing-form, species of this sub-family may be easily recognized. Often their size is extraordinary, for members of Cocytius, a South American genus, which includes the largest known Sphingidse, expand as much as eight and nine inches across the wings. The length of their tongue calls for similar remark, and some represent the extreme of development in this direction (see

Fig. 41). A tongue five or six inches long is nowise uncommon; that of a tropical African attains to seven and a half inches; the proboscis of Cocytius chientitis reaches nearly two inches more! and Dr. Wallace some years ago predicted with confidence the discovery of a Sphinx in Madagascar with a tongue even of eleven or twelve inches, which could reach the nectar in the largest flowers oi AngrcEcuni sesqiiipcdalc, a singular Madagascar orchid, whose immensely deep nectaries vary in length from ten to fourteen inches. At the other end of the scale are forms like Ellcina harrisii oi the United States, where the organ is obsolete, or a mere membraneous rudiment. Another distinguishing feature of a large number of species in this group consists in their tendency to spinose, or armed tibiae and tarsi, which in the Choerocampince is barely indicated in Deilephila.

These insects, as well as the sub-family Smerinthinse, pupate in the earth without silk, an event more dangerous to the individual than in the cocoon-making groups, for the roving larvce, seeking shelter, may find the

THE HAWK MOTHS {SPHINGIDM).

ground unsuitable, and fall ready victims to attack. Their flight in imago is crepuscular and nocturnal without exception. There is thus a correlation between habit and structure; and, as we have seen, the hio^her Ma- Fio. 42. -Hawk moth {Lophostethiis duinolinii), from croglossinse and Port Natal. have a surface pupation andChoerocampince—which may use silken to discard the ordinary habit of threads—tend the Heterocera and become day-fliers.

MandMcince.

The sub-family Manducince has always attracted attention, with its type MandiLca atropos, the well-known Death's Head Moth, which is famed for its peculiar coloration and the squeaking sound that it utters. The pattern and colours, the ringed abdomen, and the contrast between the fore- and hind-wings, ally this Old World group with the typical hawk moths.

SmerinthiiicB.

At the foot of the series stand the Smerinthince, or Eyed Hawks, with dentated wings more or less, small Q

retracted head and thorax short and broad, and antennse shghtly pectinated in the males; insects often exceedingly richly coloured. In their maxillae, or proboscis, they offer a striking contrast to the Sphinginse. It is short or wanting, and of course, minus a tongue, the moths are incapable of feeding. They are heavy and sluggish in motion; the wings are not built for rapid or sustained flight, consequent upon the poorly developed state of the thoracic muscles. But they fly to light, and in this way many are taken. Withal they are truly Sphingiform in larval and imaginal characters, and have the anal horn, but the insects are thoroughly bombici-form in habit and appearance (see Fig. 42).

One of the distinguishing characters of the Sphingidai, the reader is aware, is their smooth, hairless larvae. Strange to say, it is a received opinion that they are an outgrowth of a spinous or bristly haired larval group, the posterior spine, or caudal horn, of Sphingidae being regarded as a remnant of a general spinous covering. Probably the horn is developed from one or more spines or bristles, the skin itself at the base of which has been prolonged, and stiffened by chitine.

In form and structure the Sphingidae seem to be most closely related to the American group of the Ceratocampinae. If we regard the larvae of the latter, we see the anal horn become stouter and more developed through the series Dryocampa, Anisota, Citheronia; the

spines are gradually lost as the caudal horn became variously formed. The Sphingidce have become smooth, and show only a thoracic crest or the anal spine represented by a horn. Probably the Sphingidse were cast off from the Bombyces or Spinners parallel with the Ceratocampinae. That the Sphingidce may have been evolved from the ancestors of the Ceratocampinas we have reason to believe. The sub- family Smerin-thinai would seem to be descendants of the oldest forms of the Sphingidai. The small and sunken head, the shape of the thorax, and the pectinate antennae are probably low characters in the Hawk Moths, and recall the Bombyces; as also the subterranean pupation without silk, together with the nocturnal flight. The mode of flight of the Smerinthinae, which is opposed to the characteristic manner of other hawk moths, and their rudimentary mouth-parts, which prevent them feeding in the perfect state, likewise show affinity to the Bombyces. It is therefore manifest that these two marked features of the hawk moths— that they feed freely and are highly specialized in relation to flowers-were wanting in their Bombyciform ancestors, and are still wanting in Smerinthus.

When we turn to the general distribution of these moths, we find that while the Old World possesses a somewhat fuller and better representation of the higher groups, in America the grey, moth-like Sphinginae exist

in the greater number of forms. The representation in the Old World is the more brilliant of the two, owing to the number of bright-coloured Choerocampinse of the Himalayan region. In respect of colour, America has the advantage, however, as regards the Smerinthinae; both Calasymbolus and Paonias, for example, are extremely beautiful. North America is indeed peculiarly rich in species belonging to the more typical ocellated group; but the less typical unocellated genera are not well represented.

Sphingidir have their Metropolis in the Tropics.

The habits of the Sphingidai, it need hardly be said, render them quite unsuited to cold, rigorous climates. It is in the tropics, where they revel in warm sunshine and a luxuriant flora, that they have their metropolis where they reach the highest development in kinds and numbers. The family is not represented in Iceland, nor in Labrador, in all probability; but they occur in Van-couver and in Newfoundland, and in Upper Canada the majority of those inhabiting the Middle States may be found. Hemaris diffinis extends further north than most other species.