380 
and Watsonville, Cal., was brought to the attention of this Department 
in 1891. Specimens were first sent May 22, 1891, by Mr. W. A. Gaff'y 
to the Assistant Secretary of Agriculture, with the statement that 
1,000 acres of promising sugar beets were all more or less affected 
by the insect. Dr. Eiley sent Mr. Koebele in June to the spot, and 
while his observations did not result in the ascertaining of practical 
remedies, he collected material from which the accompanying figure of 
the different stages of the insect has been dra wn. On June 6 he col- 
lected about 2,000 eggs of the insect, all before mid-day, and nearly all 
on the underside of the leaves. All but about 10 had hatched on June 9, 
and the remaining 10 were mature the following morning, indicating 
that the insect remains in the egg state for from three to four days. 
Fig. B9.—Pegomyia vicina : a. surface of egg, very highly magnified; b, larva; c, last segment of same; 
d, anal spiracles ; e, head ; /, thoracic spiracles; g, cephalic hooks of larva; Ii, puparinm; i, adult fly; 
k, head of adult male; I, head of female— b, h. i, enlarged, other figures still more enlarged (original). 
On June 7 two plants, which Mr. Koebele had brought to his home in 
Alameda, were cleaned of all larvae and stocked with unhatched eggs. 
On June 8 the young larvae began to mine the leaves, and by June 11 
had become nearly full grown. They did not transform to puparia, 
however, until June 16, making the length of the larval state to be 8 
days, which, however, is probably shortened under perfectly natural 
conditions. While in the field he also collected about 300 larvas, most 
of which pupated on June 8. The first flies issued June 28 and the 
remainder the following week. We have, then, as the duration of a 
generation, egg stage, three to four days; larval stage, seven to eight 
days; puparium, twenty days, or about one generation per month. 
As above stated, the attention of the Department was first called 
to the matter in May, when the work of the insect was already 
