Direction Leaflet Number Three HOW TO COLLECT INSECTS AND SPIDERS FOR SCIENTIFIC STUDY By ALICE GRAY Department of Insects and Spiders The American Museum of Natural History A collection of insects and spiders, like almost any other collection, derives its value from its scope, its condition, and the extent and accuracy of the information which it conveys. A theoretically perfect entomological collection would contain many perfect specimens of both sexes of every existing kind, from every possible locality, and every day of the year, together with a complete account of the life history and habits of each creature. Of course, this ideal has not even been approached by the combined efforts of all the collectors since the beginning of systematic biology; but any student, professional or amateur, if he is a careful workman and an accurate observer, can contribute something toward its achievement. He may, quite possibly, discover one or more new species, although he must be very highly trained to recognize them. He is far more likely to record an old species from a new place, or to observe some familiar creature about its unfamiliar business. That is why the habit of note-taking is so important to the scientific collector. Virtually nothing is known about the private lives of the great majority of insects and spiders. Any one who watches them work in their natural habitats and writes down exactly what he sees, season by season, is certain, over a period of years, to amass a great deal of information hitherto unknown. This kind of work is an important part of the science of Ecology. To do it, you need patience, persistence, and an orderly method of recording your observations. You must keep at least one specimen associated with each item of information, so that no mistake in identity is possible, and bits of an insect's story picked up at various times and places can be assembled with certainty, even though you may not know the creature's name. The species must, however, be identified before you attempt to make your observations known. Many beginners will find it interesting and profitable to establish correspondence with professional or advanced amateur entomologists of kindred tastes. Almost any University, Natural History Museum, Entomological Society, or State Department of Agriculture could put you in touch with some of them. They are happy to guide your choice of technical literature, and to help with difficult identifications. If you happen to make an important discovery, they can tell you what to do about it. In return, they may ask you for duplicate specimens of interesting species and permission to quote you, among other observers, on topics pertinent to their own investigations. This amicable association is one of the pleasant things about a scientific hobby, and a source of satisfaction to both the beginner and the experienced student. WHEN AND WHERE TO LOOK FOR INSECTS Unlike some other animals, most insects stay in one general locality day and night the year round, and may be found at any time by a collector who can recognize them in all stages of development, and who knows their habits well enough to guess what they are doing under the prevailing circumstances. To be sure, you can catch more specimens per hour of collecting in summer than you can in winter; and although many insects are abroad by night you are less apt to see them than the diurnal species; but out-of-season and odd-hour collecting are much more likely to produce unusual results. There are more species of insects in the world than of all other animals together, and probably more individual insects than any other kind of creature large enough to see with the unaided eye. As might be expected of so great a population, they inhabit practically every habitable portion of the globe. With the single apparent exception of the depths of the sea, all imaginable and some unimaginable places have their six-legged residents. Insects abound, for instance, upon and beneath the earth itself. You can find them scuttling over bare rocks, the open sand of beaches and deserts, the loose soil of gardens, the beaten paths of the country, and the pavement of city streets. They creep about under the grass of lawns, the moss of forests, and the lichens of the arctic tundra. They lurk beneath stones, logs, compost piles, fallen leaves, and flood derbis of river and seashore. In arid regions, the roots of plants