CHAPTER XVII
SPHINGES
We have already observed the chief features by which we are able to distinguish between butterflies and moths ([page 56]), so we shall devote the present division to a description of the characteristics and life histories of some of the latter insects.
The number of British butterflies is so limited that space could be found for a brief description of every species, but with moths the case is very different. There are about two thousand known British species of this division of the Lepidoptera, and every year adds some newly discovered insects to this long list; we shall therefore have to content ourselves with making a selection of these for individual mention.
In doing this I shall endeavour to provide the young entomologist with a fairly representative list—one that will enable him to become more or less intimately acquainted with all the principal divisions of the Heterocera; and his attention will be drawn especially to many which may be described as 'common' or 'generally distributed,' so that during his first few seasons at collecting he may be enabled to identify and study a fair proportion of his captures. Occasionally, however, one of the rarer species will be described in order to illustrate some striking characteristic.
We shall commence with the tribe of Sphinges or Hawk Moths.
This group consists of three families—the Sphingidæ, including the largest of the 'Hawks,' and the 'Bee Hawks,' the Sesiidæ or 'Clearwings,' and the Zygænidæ, including the 'Foresters' and the 'Burnets'—numbering in all about forty species.
Family—Sphingidæ
This family is named from a fancied resemblance of the larvæ to the celebrated Egyptian sphinx. The perfect insects have very thick bodies, generally tapering toward the tail, and their wings are rather narrow in proportion to the length, but are exceedingly powerful, and the flight is, with one or two exceptions, very rapid. The antennæ terminate in a small and thin hook.
Most of these insects fly at dusk, but a few delight in the brightness and heat of the midday sun. In either case the velocity of their flight is generally so great that it is a difficult matter to follow them with the eye, and a still more difficult matter to secure the insects in the net; consequently, the best way to study them is to search out the larvæ on their food plants, and rear them till they attain their perfect form.