15 



are rapidly increasing, although it continues to liv^e b}^ preference on 

 weeds and wild plants. The crops most injured are beets, spinach, 

 and saltbush; and natural food plants are chickweed and lanibsquar- 

 ters. The leaves of these plants arc riddled with holes, chiefly the 

 work of the larvae, but also of the beetles, and gardeners complain 

 that spinach may ))e so badly worm-eaten that it is impossible to offer 

 it for sale. Considerable injury to beets was observ^ed by the writer 

 in 1900, and during 1902 and 1903 the insect has been the most con- 

 spicuous species on sugar beet in and near the District of Columbia. 



The larvae, as well as beetles, drop quickl}^ upon being disturbed, 

 and as the former are inconspicuous in appearance, and the latter feign 

 death, the miscreants are apt 

 to elude recognition, the 

 earl}^ injury produced being 

 frequently ascribed to cut- 

 worms and the later damage 

 to other insects. Frequently 

 from 15 to 20 larva? live 

 on a single leaf. They feed 

 mostly on the under surface. 



The beetle (tig. T, a) is shin- 

 ing black, sometimes with a 

 greenish or bluish luster. 

 The prothorax and abdomen 

 are red or reddish yellow, 

 and the legs and antenna) pale 

 yellowish. It measures less 

 than one-fourth of an inch. 

 The buff or orange eggs {7j, Ih) 

 are deposited in masses. The 

 mature larva (c) as it occurs 

 on sugar beet is dull leaden gray, with darker head and still darker 

 brown mouth parts, but on red and purple beets it takes on the color 

 of the plant attacked. This is a native species and of exceptionally 

 wide distribution, its habitat extending from New England to Mon- 

 tana, and from British America to Florida and Texas. It is one of our 

 earliest spring visitors, appearing in the lirst warm days of March in 

 the Atlantic States, and continuing a])road some vears through Novem- 

 ber. Two generations occur in the District of Columbia, the first 

 usually produced on chickweed, and later ones on beets, spinach, and 

 other plants. It is a prolific insect, as many as 180 eggs having been 

 observed to be deposited by a single female." 



5-e« 

 bb 



Fig. I.—Disduycliii, Mintlimnclucnu: a, beetle; h, egg- mass, 

 showing mode of escape of larva at right; hh, sculpture 

 of egg; c, full-grown larva; d, pupa; c, newly hatched 

 larva; /, abdominal segment of same — o, e, d, five 

 times natural size; h, c, more enlarged; bb,/, still more 

 enlarged (author's illustration, Division of Ento- 

 mology). 



«A more complete account of this flea-beetle is given in Bui. 19, n. s., pp. 80-85. 



