Wooden canisters, such as tobacco is often stored in, make very good substitutes if small holes are bored in the side. Tin canisters, or, indeed, anything made entirely of metal, unless plenty of ventilation is afforded, as in Fig. 56, have a tendency to cause the enclosed larvae to sweat.
Some few hints as to collecting larvae may not be unacceptable. In the spring, just as the buds of various low plants and bushes break forth, they should be searched by night, by the aid of a lantern, for the larvae of various noctuae and geometrae then feeding. The best plants to search will be the mountain ash, bilberry, honeysuckle, and bramble, given in their order of merit. Many other plants may be advantageously searched, in fact, all low plants and bushes ought to be well looked over by the persevering collector.
Later on, sweeping, i.e., pushing a strong ring net through the grass, may be resorted to. The net for this should be made of strong wire in the shape of the net at Fig. 46, or 43, if without the joints, a bag of strong dowlas and a stick are attached, and the front square-ended part is pushed by the collector through the grass, in order to trap any low feeding or invisible insects. When the leaves are fully out on the trees, beating will shake many larvae, pupae, certain moths, beetles, etc.., into the net or sheet spread to receive them, Both sweeping and beating may be practised by night as by day.
The situations in which larvae are found are many, some rolling themselves in nettle, oak, or other leaves; others boring into the substance of the wood itself, and some feeding in the stems of various bushes, plants, reeds, etc.. For life histories of such consult the pages of the Entomologist's Monthly Magazine, or Entomologist, both published every month at 6d. each; or Newman's "British Butterflies" and "British Moths," published as complete volumes at. 7s. 6d. and 20s. respectively. These latter are the finest works at the price in any language whatever, giving figures — perfect specimens of the wood engraver's art — of the whole of the Macro-Lepidoptera, backed up by exhaustive descriptions.
Fig. 56 — Cage for collecting larvae.
"Digging" in the dead months of the year, when the weather is mild, for pupae, is another method of getting insects. Corners where roots meet or spring from the trunks of trees, are good "harbours of refuge" for pupae; so are inner angles of walls, underneath sheltered hedgerows, or under isolated trees in parks or meadows, and a host of other spots.
The best places for "digging" are not always, as you would suppose, in the thickest parts of woods or shrubberies, but under skirting trees or in avenues. The best times for pupae are from October to January. Many people attain great proficiency in finding — the Rev. Joseph Greene, to wit. For my own part I must confess that I have never "earned my salt" at it, but that is possibly due to want of skill or perseverance.
The tools required are simply a trowel, a curved piece of steel fitted in a handle, or a three-cornered instrument similar to, but smaller than, the scraper used by shipwrights; anything, in fact, handy to carry, and efficacious in scratching up the sod at the roots of trees, or tearing off the pseudo-knots of bark which veil the pupae of various moths.
When larvae or pupae are brought home, it will be necessary to place them in something which, though retaining them in captivity, yet allows them as natural conditions of living as is possible in a circumscribed space. Pupae, may be kept in a flower pot covered with earth, or in moss damped from time to time with water of not too cold a temperature. Over the flower pot may be strained two pieces of wire or cane, crossing each other in the form of arches, the whole covered with muslin; or a handier plan to get to the insects quickly when emerged, or to damp the pupae, is to procure from the glass merchant the waste cylinders of glass cut from shades, pasting over one end with "leno" or muslin, and placing the other in the flower pot on top of the earth or moss.