HAWK-MOTHS.
About sixty species belonging to this family, scientifically known as the Sphingidæ, are recorded from the Palæarctic region, and of these twenty-seven are found in Europe. About ten only can be considered as true natives of the British Isles; seven others, though found here, are distinctly aliens, and their visits, at least as regards some of them, to our islands, exceedingly irregular.
Most of the moths are of large size, many of the caterpillars are of noble proportions, and in both stages they are not difficult to find, if looked for in suitable places and in their proper season. The caterpillars of several kinds, owing to the exposed way in which they feed or rest, are especially noticeable on bush and hedgerow; the chrysalids, although subterranean, are often freely obtained by turning up the soil around trunks of trees, or under plants, upon which the caterpillars feed.
The Lime Hawk-moth (Dilina (Mimas) tiliæ).
The four specimens shown on Plate [3] represent the more or less ordinary form of this moth. The pale pinkish grey, or reddish brown, fore wings are sometimes tinged with greenish in the paler forms; the irregular shaped band crossing the
central area of the wings is olive green, usually dark, and generally edged with whitish. This band is sometimes entire (typical), but more frequently it is broken about the middle. The outer third of these wings is more or less greenish or mottled with green, and a mark near the tip is whitish.
Variation is chiefly connected with the modifications that occur in the upper or lower, sometimes both, portions of the central band; the lower seems to be the first to disappear, then the upper passes through various stages of reduction until it becomes simply a spot or dot about the centre of the wing. Specimens are occasionally found or reared, in which every trace of the band has departed from one or both fore wings. The greenish outer border of the wings is inwardly margined with darker, well defined and band-like in some examples, but less clearly marked, or even absent, in others. Near the base of the fore wings are often two dusky greenish cross lines. The hind wings, generally pretty much of the same ground colour as the fore wings, have a dusky band-like shade of variable width on the outer third; sometimes these wings are entirely dusky, approaching blackish. Very rarely specimens are bred in which there is no trace of green colour. Such an example was reared by Mr. Frohawk in April, 1882, from a caterpillar he found in Surrey. In this aberration all the markings (normally green) are light burnt-sienna red, the usual whitish blotch at the tip of the fore wings is pink; ground colour also pink, slightly tinged with grey in places. So variable is this moth in colour and markings, that in some collections at least one cabinet drawer is given to it so that the range of aberration may be adequately shown. Already about eighteen colour modifications have been named, and at least eight band variations have also received names.
The egg is similar in general appearance to that of the next species (see Plate [4]). Dr. Chapman states that it is more densely covered with an indiarubber-like gum, and this may cause it to seem darker than the eggs of the Eyed and the Poplar Hawk-moths. The eggs are laid singly or in pairs on the underside of elm or lime leaves.
| Pl. 2. |
| Lime Hawk-moth. |
| Caterpillar and chrysalis. |