754 



REPORT UNITED STATES GEOLOGICAL SURVEY. 



Fig. 26. — Painted Mamestro. rt,huva. After Riley. 



DescripUon. — I have observed this caterpillar in different stages at Aniberst, Mass., 

 in September, 1876, when it \>as ravaging the ruta-bagas. In the yoiDuj, before the first 

 molt, the head is as wide as the bodj', pale greenish, while the body is pale greenish, 



with a double, dark, livid, dorsal 

 stripe divided by a pale median 

 line and three lateral dark stripes, 

 the uppermost of which is the nar- 

 rower ; live pairs of abdominal feet, 

 the first pair one-half as hxrge as 

 the fourth pair. The body is tuber- 

 culated, being much smoother in 

 the fully-grown larva. Length, a 

 little over a line. After the first 

 molt, when the worm is a little 

 over three lines in length, the colors 

 are much as in the fully-fed larva, 

 being deep yellow, with a broad, 

 black, dorsal band, sometimes 

 entire and sometimes divided by a 

 median pale line. A lateral area 

 is marbled with transverse, short, 

 black and white lines, and with a 

 row of conspicuous black spots. A 

 row of dark spots down on the sides. 

 Head reddish testaceous; abdomi- 

 nal feet reddish. After the third 

 molt, when the caterpillar is one inch long (observed September 16,) "the markings 

 are nearly the same as the mature caterpillar. The fully-fed larva is unusually long, 

 cylindrical, about two inches in length, the body tapering slightly toward the head, 

 which is orang'!-red. A broad, dorsal, dark line, edged with yellow, with two white 

 dots in the middle of each ring. A broad, lateral, white band, traversed by rune- 

 like black lines, inclosing a line of large black dots, one in the lower edge of each ring. 

 A lateral line of yellow, below which is a marbled line of white and black dots. Legs, 

 both thoracic and abdominal, and under side of the body, tiuged withorang'. The 

 moth is clear reddish-brown, with a purplish tint, on the head, thorax, and fore wings, 

 while the hind wiugs are whitish, contrasting strongly with the rest of the body. The 

 hind body, or abdomen, is dull ash-gray. Fore wings with a conspicuous, light, round 

 spot in the middle of the ring, beyond which is a kidney-shaped light spot, containing 

 a dark ring. The veins are darker than the rest of the wing, and firmly spotted with 

 light scales. It expands a little over an inch and a half. 



The Cabbage-Plant Louse, Aphis hrassicce Linn. — Sometimes gathering in immense 

 numbers on the outer leaves ; a woolly, greenish louse, the winged ones spotted with 

 black, disfiguring the heads. 



This insect is Ccalled by Curtis, in his '' Farm Insects," the cabbage and 

 Swedish turnip-leaf plant louse; the species that I have observed in 

 Maine and Massachusetts is without much doubt the same as the Euro- 

 pean. 



It has not yet been known to be specially injurious in the JS'ew England 

 States, though liable at any year to be so. In New York, however, in 

 one case it has proved very destructive, as in the following case cited 

 by Dr. Fitch : " J. L. Edgerton, of Waverly, N. Y., "states (Country 

 Gentleman, July, 1857, p. SO) that his patch of cabbages the year before, 

 comprising three hundred and fifty large, thrifty plants, were attacked by 

 licejustas they were beginning to head, and in three weeks every plant was 

 covered by these vermin and he lost the whole, neither ashes nor salt hav- 

 ing any eiiect upon them." From July, says Fitch, to the close of the 

 season it may be found on the plants, either solitary or in clusters, inhab- 

 iting for the most part the upper sides of the inner leaves and the under 

 sides of the outer ones. It is in the former case that it is most pernicious 

 by sucking the juices from and weakening this part, whereby it heads tar- 

 dily and imperfectly, or, if thel ice are numerous, no head is formed and 

 the plant is worthless. The ruta-baga, er Swedish turnip, is also in 

 this country, says Dr. Fitch, subject to its attacks, " the under side of the 



