590 
Journal of Agricultural Research 
Vo!. XIV, No. 13 
opening. The galls at this date appeared to be fully grown. Besides 
the stem mother, there were, in each gall, a few winged "lice” quite 
dark in color, a good number of pupae of varying sizes, the small ones 
being quite pale in color, and numerous small larvae which were very 
light colored and heavily tufted with white waxy threads. The old gall 
mother seemed to be the sole parent of the gall colony, all of which 
normally acquire wings. 
The stem mothers were a yellowish sordid green in color, very plump, covered with 
a fine white powder; head, the entire legs, including coxae, and tips of the antennae 
dusky to blackish; antenna 4-jointed and very short, not as long as hind tibia, in 
length approximately 0.40 mm.; length of body 2.50 to 3 mm.; joint 3 distinctly 
longer than joint 4 with spur, the proportion being about as 3 to 2; length of hind 
tibia 0.50 mm.; eyes very small. There are upon the dorsum six longitudinal rows 
of rather large wax plates beginning upon the mesothorax and extending to the seventh 
abdominal segment. Upon the prothorax and the eighth abdominal segment the 
number of plates is reduced to four (Pi. 81, C, H). 
The writer also examined, in connection with this description, numerous 
specimens taken in Louisiana by Mr. T. H. Jones, in California by Messrs. 
E. Bethel and George P. Weldon, in Arizona by Mr. Bethel, and on the 
eastern and western slopes of the mountains in Colorado by Messrs. L. C. 
Bragg and C. P. Gillette. 
It seems certain that the wingless stem mother that starts the gall of 
this species early in the season normally continues to feed and reproduce 
until the leaves mature in the fall, all of her young acquiring wings and 
going in search of the alternate food plants of the family Cruciferae. 
FundaTrigenia migrant prom the gales. —In color and general appearance like 
the winged sexupara from turnips and Brussels sprouts. The specimens examined 
average about 0.25 mm. shorter in body length. The differences in the antennal 
segments are quite marked. Joint 3 has from two to six transverse sensoria, the usual 
number being three or four. Joint 4 is the shortest and weakest and rarely has a 
small sensorium. Joint 4 being somewhat smaller, and joint 5 slightly larger than 
in the sexupara, the contrast in size of these segments is very noticeable. The per¬ 
manent sensoria on joints 5 and 6 are very large and irregular, and even may be cut 
into two by projecting chitinous margins. They always have upon their surfaces 
small chitinous pieces, one or two on joint 5 and two to four on joint 6, each bearing 
one or more short hairs. Upon joint 6 this large irregular sensorium may extend 
from the base of the spur to the middle of the segment and is nearly always very 
irregular in outline. The proportions of the segments are about as follows: 1, 21; 
2, 30; 3, 66; 4, 31; 5, 39; 6 with spur, 68. There are many irregularities in the antennae 
of this species, one of which is the frequent union of segments 3 and 4 into one (PI. 
81, J). 
Wingless viviparous female. —Described from specimens taken by 
Mr. T. H. Jones at Baton Rouge, La., from the roots of Brussels sprouts, 
on April 2, 1917. 
General color sordid pale yellow, with head, antennae, and legs dusky brown to 
blackish; tarsi and eyes black; length 2.50 mm.; width 1.60 mm.; antenna 0.45 mm., 
joints 3, and 5 plus spur, subequal; joint 4 much the shortest, being less than one- 
half as long as joint 3; beak barely attaining second coxae; hind femora and tibiae 
