INSECT LIFE UNDERGROUND.

L. O. HOWARD, PH. D.,
Entomologist U. S. Department of Agriculture, and Curator Department of Insects, U. S. National Museum.

THERE is an old German child's story of a little girl who being told that if she could find a place to hide her first silver piece where no eye could see her, and then dance round it three times, she would have her wish. She sought everywhere for such a place, but always some bird or squirrel or mouse or insect was near by, and even when she dug beneath the ground, there too were little crawling creatures watching her.

It may be said that this story was meant to show that animal life is found almost everywhere, and certainly beneath the surface of the ground there are hundreds of kinds of insects working steadily away at their different occupations; for whatever disagreeable things you may find to say about insects, you can never justly call them lazy. The scriptures recognized this fact in the well-known command to the sluggard, and the old nursery rhyme about the "busy bee" emphasizes the same characteristic.

The truest underground insects are those which pass their entire lives beneath the surface of the earth; which are born there, live and grow and die without seeing the light of day. Such, for example, are the true cave insects, a number of forms of which are found in the great caverns in different parts of the world. Some of these insects feed upon the vegetable molds and low forms of plant life found in caves; others feed on dead animal matter and still others upon living insects. Nearly all are of pale colors and are blind or nearly so, for they have no use for eyes in the darkness. All are supposed to be descendants of above-ground forms, which through many generations of life in the darkness have lost their color and their power of sight. The genealogy of these true cave forms may be guessed at with some certainty, for we know insects which are only partly transformed in structure from above-ground forms to true cave species. Such are certain beetles which live in the catacombs of Paris, and certain other insects which have been found in the old and deep burrows of the land tortoise in Florida.

But we do not have to go to caves to find many other true underground insects. Rich, loose soil abounds in such creatures which live upon the decaying vegetation (soil humus or vegetable mold) or upon one another. The most abundant in numbers of individuals are the little spring-tails or bristle-tails, minute creatures seldom more than a sixteenth of an inch in length and which frequently swarm in the ground in such numbers that the earth seems fairly alive. These little creatures are by no means confined to the surface soil, but have been found in great armies at a depth of six feet or more in stiff clay, which they have penetrated by following the deeper rootlets of trees. Certain of these little insects have also become so accustomed to this lightless life that they have lost their eyes.

Other true underground insects are found in the nests of ants, where they fill many different functions. They may be grouped, however as follows: 1. Species which are fed by the ants and from which the ants derive a benefit by eating a certain secretion of the insect. 2. Species which are treated with indifference by the ants and which feed upon the bodies of dead ants and other animal and vegetable debris to be found in ants' nests. The ants are certainly not hostile to these insects and evidently gain some unknown benefit from their presence. 3. Species which live among the ants for the purpose of killing and feeding upon them. The first true ants' nest insect was only discovered and studied at the beginning of this century, but since that time hundreds of other species have been found, and a mere catalogue of their names fills a book of over 200 pages.

BEETLES.
272.CHICAGO:
A. W. MUMFORD, PUBLISHER.
(CHLAENIUS
SERICEUS.)		(LIBIA
GRANDIS.)		(CICINDELLA
REPANDA.)		(CICINDELLA
GUTTETA.)		(CICINDELLA
LECONTEI.)		(BRENTHOS
MANTIS.)
(ALAUS
GARGOPS.)		(PASMACHUS
MARGINATUS.)		(NECROPHORUS
ORBICOLLIS.)		(DICAELUS
PURPURATUS.)
(CALOSOMA
SCRUTATOR.)		(COTALPA
LANIGERA.)		(CYCHRUS
ANGUSTICOLLIE.)		(CALOSOMA
CALIDUM.)
LUCANUS ELEPHAS (Male).
CYNASTES TITYUS.
PASSALUS CORNUTUS.