Rose Bug, a diurnal beetle of the melolon-thian group, the melolontha subspinosa (Fab.) or macrodactylus subspinosus (Lat.). It is about 7/20 of an inch long, buff yellow above and white below, with a slender body tapering before and behind, entirely covered with very short ashy yellow down; thorax angularly widened in the middle of each side, which suggested the specific name; the legs slender, yellow or pale red, with the joints of the feet very long and tipped with black. This insect, one of the greatest pests in gardens and nurseries, was unknown in northern New England until within 50 years; its annual appearance coincides with the blossoming of the rose, whence the common name; it attacks also grape vines, young apples and other fruits, garden vegetables, corn, forest trees, and even grass, devouring flowers, leaves, and fruit. They arrive in swarms unexpectedly, and disappear as suddenly; they emerge from the ground about the second week in June, and remain 30 or 40 days, when the males die, and the females enter the earth, lay their eggs, and return to the surface to perish; the eggs are about 30, nearly globular, whitish, 1/30 of an inch in diameter, placed from 1 to 4 in. below the surface, and hatched in 20 days.
The larvae begin at once to feed on tender roots, and by the autumn are nearly three fourths of an inch long and one eighth of an inch in diameter; they are yellowish white, bluish toward the posterior end, with a few short hairs; there are six short legs, a pair to each of the first three rings behind the head, the last part covered with a horny shell of a pale rust color; in October they descend below the reach of frost, and pass the winter in a torpid state; in the spring they come toward the surface and form little shells of earth, within which they are transformed during May into pupae; these are yellowish white, with stump-like wings, legs, and antennae folded on the breast, and the whole enclosed in a filmy skin which is rent in June, and the perfect beetle digs its way to the surface. As they are beyond reach during the egg, larva, and pupa states, they can only be exterminated as perfect insects; they are destroyed by crushing, scalding, and burning, after being shaken daily from the infested plants. They are occasionally found in immense numbers on the flowers of the worthless whiteweed (chrysanthemum leucanthe-mum); in this case it is expedient to mow it, and consume it with them on the spot. It is said that they never infest the cinnamon rose.
This is one of the most destructive of insects, in some places in the west having consumed year after year the crop of young apples; choice fruits in such cases can only be preserved by covering them with netting. Insectivorous birds devour these beetles; moles and various predaceous animals and insects also eat them; young chickens are said sometimes to be killed by the irritation produced by the prickly feet and sharp claws of these insects which they have swallowed. - The European rose chafer is another allied lamelli-corn beetle, the cetonia aurata (Fab.).