The larvæ of the Ant-lions live on the land, and are carnivorous. When about to undergo their transformation into pupæ, they spin for themselves a silky cocoon. The larvæ of the Phryganeas, on the contrary, live in the water. They surround themselves with a sort of protecting case, composed of a silky shell and incrustations of all sorts. The pupæ, as well as the larvæ of these insects, breathe by means of gills.
| Fig. 402.—Ant-lion's funnel. | Fig. 403.—Larva, cocoon, and pupa of the Ant-lion. |
The Ant-lion (Myrmeleo formicarius, [Fig. 401]) is found in the environs of Paris. It is an elegant insect, resembling the dragon-fly, but is distinguished from it by its antennæ. Its larva is of a rosy, rather dirty grey, with little tufts of blackish hair on its very voluminous abdomen. Its legs are rather long and slender; the two anterior pair of legs are directed forwards, whilst the hind legs are fixed against the body, and only permit the animal to walk backwards. These larvæ are met with in great abundance in sandy places very much exposed to the heat of the sun. There they construct for themselves a sort of funnel in the sand ([Fig. 402]), by describing, backwards, the turns of a spiral whose diameter gradually diminishes. Their strong square head serves them as a spade with which to throw the sand far away: they then hide themselves at the bottom of the hole, their head alone being out, and wait with patience for some insect to come near. Scarcely has the ant-lion perceived its victim on the borders of its funnel, when it throws at it a shower of dust to alarm it, and make it fall to the bottom of the precipice, which does not fail to happen. Then it seizes it with its sharp mandibles, and sucks its blood; after which it throws its empty skin out of the hole and resumes the look-out. Ants especially become its prey, whence its name of Ant-lion. Towards the month of July, the larvæ make themselves a spherical cocoon, mixed with grains of sand, in which they are transformed into pupæ which are hatched towards the end of August. The perfect ant-lions diffuse an odour of roses; their flight, which is weak, distinguishes them from the dragon-flies. We meet in the south of France with a very beautiful species of Ant-lion, the Myrmeleo libelluloides ([Fig. 404]); its larva can move forwards, and does not dig itself a funnel.
Fig. 404.—Myrmeleo libelluloides.
The genus Ascalaphus ([Fig. 407]) is remarkable for the long clubbed antennæ of its members, and for their rapid flight. They like the sun, and live especially in hot countries; however, one meets with the Ascalaphus, in the month of July, near Paris, on the dry declivities of Lardy and of Poquency. Their larvæ ([Fig. 406]) have mandibles adapted for suction. They watch for insects under heaps of stones, and spring upon their prey.
| Fig. 405.—Larva of Myrmeleo libelluloides. | Fig. 406.—Larva of Ascalaphus. | Fig. 407.—Ascalaphus meridionalis. |
The first states of the Nemoptera [119] ([Fig. 408]) are as yet little known. They are insects with wings spotted with yellow and black, the lower ones almost linear, and are met with in southern countries, and but very rarely in the south of France.