[Myrmecophilous and Termitophilous species.]—The early spring is also the best time for collecting the Myrmecophilous and Termitophilous Coleoptera. Termitophilous species have in North America hitherto been found only in connection with the White-ants (Termes flavipes), and the inquilinous beetles are found running among the White-ants in the colonies under stones, loose bark of trees, and more numerously in the interior of old infested trees. Myrmecophilous Coleoptera are by far more numerous in species than the Termitophilous species and are found among many species of ants which have their nests either under stones or loose bark of trees, in stumps or logs, or which construct larger or smaller hills. Upon uncovering a colony of ants under a stone, the underside of the latter as well as the galleries of the ants in the ground should be carefully examined for inquilines, which from their greater or slighter resemblance to the ants are liable to be overlooked by an inexperienced collector. If such colony of ants harbors a rare beetle the subterranean part of the colony itself should be dug out and sifted, but since from the stony nature of the ground this is not always practicable it is to be recommended to carefully replace the stone under which the colony has been found. Upon revisiting the spot again the next day or even a few hours after the first visit additional specimens of the inquilines are usually to be obtained on the stone or in the superficial galleries of the ants. Ant colonies in hollow trees and in rotten logs should be sifted and there is no particular difficulty connected with this operation. Owing to the pugnacious character of the hill-constructing ants it would seem to be a rather unpleasant task to examine a strong and vigorous colony for inquilinous beetles, but the collector must not mind being bitten and stung by the infuriated ants, and after a little experience he will find that it is not such a difficult thing after all to attack even the largest ant-hill. The only thorough way of investigating such ant-hills is to sieve the same, which can be easily done if the hill is composed of sticks and other vegetable débris. If it is built of earth or sand the process of sifting is more difficult and tedious. Another method of securing specimens of these inquilinous beetles is to place flat stones or similar objects on the surface of the ant-hill and to examine them occasionally, when the beetles will be found on the underside of the traps.
[Spring Flights of Coleoptera.]—On the first really warm days of spring commences the “swarming” season of Coleoptera, when all winged species are flying about, especially toward evening. On favorable days the number of specimens and species that can thus be found is astonishingly great, and this is one of the few occasions when the Coleopterist can advantageously use a light butterfly net. The flying beetles preferably alight and rest on the top of wooden fences (especially newly made ones), on the railings of bridges, etc., where they can be easily seen and secured, or they are attracted in great numbers by the white-painted surface of buildings. This flying season lasts in the latitude of Washington from the end of April to the middle of June, but favorable days are not of frequent occurrence, since a peculiar combination of atmospheric conditions appears to be necessary to induce the Coleoptera to fly about in great numbers.
[Beach collecting.]—Along the shores of the ocean and the Great Lakes untold numbers of Coleoptera and other insects fall at this season into the water, and, if the tides, the currents, and the winds be favorable, they are washed ashore by the waves on the sandy beaches, where they often form windrows several inches in height and width. If the collector is happy enough to be at the right place on the right day he has then the opportunity to pick up hundreds of rare species within a very short time and without any trouble. Many of the specimens thus washed ashore are dead and decayed, but the majority are alive and in excellent condition. This “beach collecting” affords also an excellent opportunity for the Hymenopterist and Hemipterist to secure large numbers of rare species, but favorable days are also here of rare occurrence.
[Attracting by Lights.]—On the beaches, day and night flying insects can thus be captured. Away from the beach night-flying Coleoptera can best be collected at the electric lights of our cities; but, as in the Lepidoptera, not all night-flying species are attracted by the light. Gas and other lights also attract Coleoptera, and the various “light traps” that have been devised and described can advantageously be used for collecting these insects.
Fig. 65.—An Elaterid
(Pyrophorus noctilucus).
(From Packard.)
[Traps.]—The method of “sugaring,” so important to the Lepidopterist, is by far less favorable for collecting Coleoptera. Still, certain rare Carabidæ, Elateridæ, and Cerambycidæ are attracted by this bait, and the Coleopterist should not entirely ignore this mode of collecting. There are a few other methods of trapping certain Coleoptera. By laying out dead mammals, birds, fishes, snakes, etc., on suitable places and so that they are protected from dogs, rats, etc., the carrion-feeding Coleoptera can be found in great abundance, but a cleaner and less disagreeable method of obtaining them is to bury in the ground tin cans or glass jars so that the top is even with the surrounding ground and to bait them with pieces of meat, fried fish, boiled eggs, etc. Many Curculionidæ, Scolytidæ, and numerous other wood-inhabiting species can be successfully trapped in the following way: A number of branches, preferably of only one kind of tree, are cut and tied up into bundles of convenient size. The bundles are then laid on the ground in a shady place or firmly fastened on trunks of trees. When the cut branches begin to get dry they will attract many of these Coleoptera, which can then be readily collected by shaking the bundles out over the collecting cloth.
[Freshets.]—Freshets usually take place in springtime in most of our rivers and creeks, and furnish the means of obtaining a multitude of Coleoptera, among which there will be many species which can not, or only accidentally, be found otherwise. These freshets, sweeping over the low banks or inundating wide stretches of low land, carry with them all insects that have been caught by the inundation. Intermingled with, and usually clinging to, the various floating débris, these insects are eventually washed ashore by the current at various points and the Coleopterist should not miss this rare opportunity, but go out to the river bank at a time when the water is still rising, or at least when it has attained its highest point. Among, or on the washed up débris, a multitude of Coleoptera of various families can be found, and the specimens can either be gathered up on the spot or a quantity of the débris be put in sacks and taken home, where it can be examined more thoroughly and with greater leisure than out of doors. A day or so after the floods have receded the washed up specimens will have dispersed and only a few will remain in the débris for a longer period. Still more profitable than the spring floods are the summer freshets, because a larger and more diversified lot of Coleoptera is then brought down by the water. A similar opportunity for collecting is offered near the seashore if unusually high tides inundate the low marshes along the bayous and inlets.
Fig. 66.—A Longicorn
(Prionus laticollis).