Beetle, or Scaralecus, L. a well-known insect, of which there are eighty-seven species, of one common formation, having cases to their wings, which are the more necessary, as they mostly live beneath the surface of the earth. Besides their diversity of shape and colour, the difference in the size of the various species is also considerable, some not being larger than the head of a pin, while others, as the elephant beetle, are as big as a closed hand.
The May-bug, or cock-chaffer, is the Species most deserving of our notice, on account of the formidable ravages it commits on the territory of the husbandman. In some seasons, it has been found to swarm in such numbers, as to devour every vegetable production; our principal object, therefore, will be to point out the best means for its destruction. It is necessary to observe, that the insect is first generated in the earth, from the eggs deposited by the fly, in its perfect state. About three months afterwards, the insects contained in those c break the shell, and crawl forth in the form a small grub or maggot, which feeds upon the roots of vegetables; and continues in this concealed and destructive state for more than three years, gradually growing to the size of a walnut. it is the thick white maggot with a red head, so frequently found on turning up the earth. At the end of the fourth year, these extraordinary insects emerge from their subterraneous abode ; when, in the mild evenings of May, an attentive observer may perceive them rising from the earth in numbers before him.
The willow seems to be their favourite food; on this tree they hang in clusters, and seldom quit it till they have completely devoured its foliage. Rooks are particularly fond of them, when in their state of grubs ; and hence the prejudice of fanners against these birds is ill-founded. In Ireland, the damage done by the beetle was at one time so great, in a particular district, that the inhabitants came to the resolution of setting fire to a wood of some extent, in order to prevent their propagation.
As these insects cannot support the heat of the mid-day sun, and therefore conceal themselves till evening under the leaves of trees, the most effectual way of destroying them is to beat them off with long poles, and then to collect and. burn them : or, according to Dr. T. Molynkux, they are very beneficial for fattening poultry. Smoke is extremely offensive to them, consequen'ly, the burning of heath, fern, or other weeds, will prevent their incursions in gardens or ex pel them if they have entered. The leaves of the young turnip are sup-posed to be devoured by this fly, which Dr. Darwin conceives may be destroyed by rolling.
Another simple method, which is so well known, that it scarcely deserves to be mentioned, is, to place a vessel with any liquid, with pieces of board in an oblique direction, to facilitate their ascent to the edge of the vessel, over which they will fall into the liquid.