Continuing the search, we meet with leaves that are rolled up and bound with silk threads, and others that are drawn together and similarly bound. These are carefully uncurled and pulled asunder with the result that active little larvæ are exposed to view, or, it may be, pupæ are discovered. In some cases flowers are drawn together in just the same way, and an examination reveals one or more of the species that prefer petals and other parts of flowers to the green leaves.
Silken threads always arouse our suspicions. These may be seen lying on the surfaces of leaves, and passing from one leaf to another, or they may be hanging perpendicularly from the branches of trees above. In the latter case a larva may be frequently seen on the lower extremity of the fibre, swinging gently in the breeze, and, should we require it, we have only to place the open box below for its reception.
Hawthorn and other trees are sometimes seen almost devoid of leaves, nearly every bit of green having been greedily devoured by a host of small larvæ. In such cases we often meet with dense clusters of silk fibres that may easily be mistaken for spiders' nests. But when we look more closely into the structure we observe that we have discovered instead nests of gregarious larvæ, such a large number being in each little community that the deplorable appearance of the tree is at once explained.
A little farther on we meet with a sickly-looking plant in the midst of a number of flourishing individuals of the same species, and stop to make inquiries into the cause of this strange occurrence. Is it due to a poorness of the soil? No, this cannot be the case; for intermingled with its roots are those of its flourishing companions. We pluck a stunted and half-shrivelled leaf and examine it. At first we do not notice the cause of its peculiar condition; but, holding it up to the light, and looking through it, we see a number of little galleries that have been eaten out of its internal soft substance, leaving the thin skin (epidermis) almost entirely intact. But nothing more is to be seen. Another leaf is examined in exactly the same way; and here we see the little destroyer, lying motionless in its burrow till a gentle pressure applied against it from outside causes it to wriggle along its narrow passage. This is the larva of one of the little leaf miners mentioned again on [page 303].
Reaching a little marshy spot we see a number of water-loving reeds, most of them beautifully green and in a flourishing condition, but here and there in their midst is a poor stunted specimen—another result of the ravages of the larvæ of one or more moths. An examination of the blades reveals nothing; but on splitting open the stalk we discover some larvæ that have already devoured a quantity of the internal pith, and thus endangered the life of the plant. On inspecting other similar reeds we are at first puzzled as to how the larvæ could get inside the stems without damaging the outer portion; but at last we see in each one a little discoloured
hole that was eaten out by the young caterpillar just after its escape from the egg. Once within the reed, it found a plentiful supply of food, and there grew at the expense of the plant without doing any further external damage save by causing a stunted growth.
It may be that the stem eaters we have found are just about full grown. If so we examine a number of the stems with a hope that we may find one or two that are just about to change to the chrysalis state, or even a pupa already formed. By this means we may secure one of the perfect insects without the necessity of feeding larvæ at home. Such a consideration becomes a most important one when it happens that the required food plant is one that cannot be easily obtained.
Close by the reeds is another water-loving plant in the form of an old willow tree. This is always an attractive object to the entomologist, so it comes in for a share of our inspection. On its leaves we may find several species of the larvæ of Lepidoptera, including those of some of our largest insects. But a strange feature catches our eyes as we happen to glance at the bark of the tree. Here we see a few holes of different sizes, about which are a number of little fragments of wood that remind us of 'sawdust;' and, examining the ground below, we see quite a little heap of this dust, looking just as if a carpenter had been at work on the spot.
This is not the effect of a saw, however; it is a sure sign of the ravages of wood-eating larvæ ([p. 224]), whose powerful jaws gain them admittance into the very hearts of trees, and the application of the nose to one of the larger holes leaves no doubt of the presence of the large and beautiful caterpillar of the Goat Moth ([p. 224]).