The Intellectual Observer: Review of Natural History, Microscopic Research ...

Ir these summer months are favourable for the study of leafmining caterpillars, and the abundance and variety of their hieroglyphics arrest our eye in every walk, and give new specimens for our cabinet, not less so are these months, from June to October, for collection of the curious and interesting Coleophorum. The moths themselves are not nearly so beautiful as the Nepticulae and Lithocolletis; the wings are lanceolate, unicoloured, or striped with silken-gray under-wings, and they sit with bodies closely pressed to the substance on which they rest, with antennæ thrown forward, much like the Tischeria.

The larvæ of this genus are the objects of our present research and interest, because their habits manifest an instinct and design which open for us a delightful field of observation. They feed upon the parenchyma of leaves, and mine irregular blotches as they feed; but with the cuticle, or leaf itself, or husk of seed, it fashions a tent, under which it walks about, and within which it retires when the time of its pupa rest has come, and the resurrection into perfect life is at hand.

As a general rule for the guidance of young naturalists, when we find a blotched or mined leaf with a round hole, as truly outlined as if drilled with a centre-bit, we may be sure that a Coleophora has been feeding there, and this little hole was the entrance into his pasture-ground, covered closely by its tent, whilst the owner penetrated into the soft, juicy parenchyma, and stretched away, as far as its body would reach, on all sides, careful only to keep its anal hooks at the tent door to secure a retreat on the least alarm.

VOL. IV.NO. I.

I have at this moment about twenty specimens of the Coleophora (Limosipennella) feeding on a branch of elm, in water, on my table, and one is under the binocular mining for its daily food; another I turned out of its pretty case that it might make a new one for my edification, and the verification of a former statement. Whilst it is uneasily walking about, wriggling its unhoused tail, and apparently measuring those serrated edges of the elm-leaf, I will give some particulars of the Coleophora as a genus of the Micro-Lepidoptera.

There are forty-one British species described by Stainton,* and many of them have been mentioned and figured by various naturalists, Reaumur, Curtis, Haworth, Duponchel, and our own Westwood, under the synonymes of Porrectaria, Ornix, Gracillaria, Astyages. At present they bear the very appropriate name of Coleophora, from Koleon (a sheath), Phoros from Phero (to bear).

The larva of a Coleophora has sixteen legs; the prolegs are very undeveloped; the six true legs are pointed and scaly as those of large caterpillars. They have invariably dark spots on the anterior and anal segment, and a horny plate on the second segment, which I imagine to be used by the insect to smooth the asperities of the leaf, as it is observed to turn about and rub its head over every part of its case previous to lining it with silk. There is also a plate on the anal segment to protect that part from the friction to which it is exposed by the protrusion of the anal segment in voiding its excrement.

These tiny caterpillars, scarcely noticed by the unassisted eye, are wonderful in their instinct, as the Lithocolletis are marvellous in their beauty. Here is a mere speck, a little brown, naked worm, busy on the leaf before me; nothing can be more insignificant in appearance, or more unworthy of minute attention; hardly does the careless eye perceive it, and yet how the detail of its structure reveals the mind of its Great Creator; the same wisdom planning, and the same goodness adapting each organ for the tiny workman that has given to man his more perfect body.

Look closely at the larva itself before we describe its proceedings. Externally we observe a small black head, with six simple eyes in a circle on each side, a pair of sharp-toothed jaws, four little palps or feelers, and a spinnaret immediately under the jaws; six true legs and ten membranous appendages, thirteen joints or segments, and on each segment a spiracle dilating and contracting as the larva breathes and moves. the anal segment there is a protuberance, armed with hooks. which it uses as a claw to attach itself to the leaf whilst making its case, and afterwards as a grappling-iron to retain possession * Vol. iv. and v. of Natural History of the Tineina, by Stainton and Zeller.

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The Intellectual Observer: Review of Natural History, Microscopic ..., 4. kötet