81 



shining, yellowish; later on it becomes dark cinnamon (fig. 3), and on 

 it the white down with which the female covers its egg becomes more 

 marked. The length of the egg is 0.5 to 0.7 mm., the width, 0.2 mm. 1 



The first egg was laid, in confinement, by one of the females on the 

 8th of October, at the lower side of a leaf in an angle of the fibers of 

 the latter. The other females laid their eggs in the hollows of leaves. 



In the orchard I investigated the apple trees infested by the blood 

 lice, and on one of the trees found on October 10, among wingless 

 nurses after they have been carefully removed from the twig, two eggs 

 of the blood louse as described above; in other places, i. e., on the 

 leaves or in the bosoms of the latter, or in the depressions of the bark, 

 etc., I did not succeed in finding eggs. 



From the eggs laid by the sexual females in a heated room young 

 nurses hatched two months later. It is possible that in nature, in long 

 continued warm weather, nurses are hatched still in the autumn, but 

 the other eggs hibernate until the spring. 



Thus, the egg of the blood louse may, with equal accuracy, be char- 

 acterized as a fall one, as Kessler and Keller do, or as a winter one, as 

 is done by E. Goethe. 



A CECIDOMYIID INJURIOUS TO SEEDS OF SORGHUM. 



By D. W.. COQUILLETT. 



In many portions of the Mississippi Valley the growing of sorghum 

 is quite an important industry; and even when not grown for commer- 

 cial purposes many farmers raise a sufficient quantity for the require- 

 ments of their several households. The plants are raised from seed, 

 and are treated like indian corn, and, although commonly known by the 

 name of sugar cane, are very different from the true sugar cane, the cul- 

 ture of which is confined to the more Southern portion of this country, 

 where the plants are commonly obtained by layering. 



On the 2d of October, 1895, two seed-heads of sorghum were received 

 at this office from Mr. 0. C. L. Dill, of Dillburg, Ala., and one from 

 Thomas J. Key, of Montgomery, Ala. An examination of these revealed 

 the fact that many of the seeds had been destroyed by the larvae of 

 some species of Cecidoinyiidoe, which had already completed their 



x Dr. H. F. Kessler, in his extensive work on the biology of the blood louse, "Die 

 Entwickelung und Lebensgeschichte der Blutlaus," 1885, gives, in an appended table 

 of drawings of the various stages of its development, some drawings which do not 

 at all conform with the reality. Thus, in fig. 6 of the table, is represented a nurse 

 giving birth to a young louse, which makes its exit with the head forward, while the 

 young lice produced by the wingless, as well as by the winged insects, come into the 

 world always with the posterior end of the body forward. Further, the drawings 

 of the sexual individuals (of the male and female, figs. 12-13) are entirely incorrect. 

 The egg is represented only diagrammatically (schematisch). In view of what has 

 just been said, we give as accurate a drawing as possible of the egg — female and 

 male — of this plant louse. — S. M. 

 8193— No. 18 6 



