Directions for Collecting and Preserving Insects

by Charles V. Riley

[Collecting the Adult.]—The implements for the general collecting of butterflies comprise the collecting net, and in some cases the beating net, although the use of the latter will not often be called for. The Rhopalocera or Diurnals may be taken about flowers, and the best season is in the early spring. Most of them are double-brooded, and the second brood will be in the greatest abundance during July and August. They are, however, to be found throughout the summer. They are also to be looked for in the neighborhood of the food-plants of their larvæ, and in the case of many species, examination of such plants affords the most satisfactory means of collecting. The food of butterflies is almost exclusively the nectar of flowers, but strangely enough they are also attracted to decaying animal matter, and many species, including rare forms, may be taken about decaying animal matter or resting on spots where dead animals have lain, or beneath which they have been buried. Moist spots of earth are also frequented by them, especially in dry seasons. Many of the larger butterflies, whose larvæ feed on the taller shrubs and the foliage of trees, will be found fluttering about the open spaces in forests, but by far the larger number, as the Browns, the Blues, the Yellows, and the Whites, which develop on the lower herbaceous and succulent plants, will be found flying over fields, prairies, and gardens. Crepuscular and nocturnal Lepidoptera, comprising most of the Heterocera, the Sphingidæ, Bombycids, Noctuids, etc., have different habits. The Sphingidæ or Hawk Moths fly in early evening, and may be collected in quantity about such plants as the Honeysuckle, Thistle, Verbena, Petunia, etc. The Bombycids and many Noctuids also fly in the early evening, but mostly at night. The former, however, do not frequent flowers, except such as are the food-plants of their larvæ, as their mouth-parts are rudimentary, and they take no nourishment.

Fig. 71.—Collecting Pill-box.
a, glass bottom (original).

Collecting by the aid of strong light is a favorite means for moths as well as other insects, and nowadays the electric lights in all large cities furnish the best collecting places, and hundreds of species may be taken in almost any desired quantity. In woods or in other situations they may be attracted to a lantern or to a light placed in an open window. Various traps have been devised, which comprise a lamp with apparatus for retaining and stupefying the insects attracted to the light. The common form is made by providing a lantern with a strong reflector. Under the light a funnel several inches larger than the lantern reaches down into a box or bottle containing the fumes of chloroform, ether, or benzine.

Fig. 72.—Method of holding and manipulating
collecting pill-box in capturing (original).

Mr. Jerome McNeill describes at length and figures in the American Naturalist, Vol. xxiii, p. 268–270, an insect trap to be used in connection with electric lights. It consists of a tin pail or can charged with cyanide after the manner of a collecting bottle, which is attached beneath the globe of the electric light.

The insects attracted by the light strike against a vertical tin screen fixed above the can and fall into a tin funnel the small end of which enters and closes the mouth of the can, and they are thus conducted into the last. A support or post in the center of the can bears a hollow tin cone, the apex of which is pierced with a number of small holes to admit light, and enters and partly closes the lower end of the funnel. The entire interior of the can is painted black and the chief light comes through the holes in the apex of the interior cone. The entrapped insects endeavor to escape by crawling up the central post towards the light coming through the small holes in the end of the cone rather than by the entrance slit about the latter and fall back repeatedly until overcome by the cyanide.

Many of the Lepidoptera will be ruined by the beetles and other insects or by their own ineffectual attempts to escape, but Coleoptera, Hymenoptera, Neuroptera, and Hemiptera are secured in satisfactory condition.

Many of the devices are very complicated and can not be described in this connection. The nocturnal species, also, fly into our houses, and this is especially the case in the country, and an open window, with a strong light reflected onto a table covered with either a white paper or a white cloth will keep one busy, on favorable nights, in properly taking care of the specimens thus attracted.