THE MEALY PLUM APHIS. 13 
The young were produced within about 12 days (in the cages mostly 
within 7 days) and at a rate of from 2 to 3 a day. The migrants, 
after they had extruded their complement of young, remained settled 
for as long as two weeks. 
MALE AND OVIPAROUS FEMALE. 
MALE. 
DESCRIPTION. 
Pupa.—wNoticeably smaller than that of the fall migrant, light yellow in color; 
eyes dark red; tarsi and distal antennal joint dusky gray. Form elongate. 
Adult.—Light clay yellow ; head, antenns, prothorax, thoracic lobes, scutel- 
lum, legs, cornicles, and Style brownish-black ; eyes dark red; stigma light green- 
ish-gray ; veins of wings brown; abdomen with a dorsomedian longitudinal row 
(segments 1 to 5 inclusive) of subcircular gray spots, similar lateral spots on 
segments 1 to 8 inclusive, and with cross bars of similar color on segments 6, 7, 
and §; genital plate and organs dark gray; beak pale yellow, tip brownish black. 
The male is almost devoid of “ meal.” 
Antennz on gibbous frontal tubercles, three-fourths the length of the body; 
comparative measurements as follows: I, 0.08 mm.; II, 0.07; III, 0.88; IV, 0.25; 
V, 0.23; VI, 0.46 (0.09 plus 0.87). Wings 2.3 mm. long. Cornicles vase-shaped, 
narrowed close to base, faintly imbricated, 0.085 mm. in length. Style conical, 
0.10 mm. long. Beak reaching a little beyond anterior mesosternal border, 0.30 
mm.long. Length of body, 2.05 mm., width, 0.68 mm. 
Circular sensoria are distributed along the antennal joints much as in the 
spring and fall migrants. They are much more numerous, there being from 38 
to 53 on III, 19 to 29 on IV, 9 to 18 on V, and the usual apical group on VI. 
¢ 
OvIPAROUS FEMALE. 
DESCRIPTION, 
Newly hatched.—Light green, appendages hyaline; eyes red. Ferm oval. 
The immature females are bright green with a very scant covering of ‘‘ meal.” 
Adult.—Greenish yellow; eyes dark red; distal half of antenne, cornicles, and 
tarsi gray; beak pale yellow, tip brown. The coating of “meal” is not so 
conspicuous as in the earlier forms, in this respect resembling the stem mother. 
Form elongate oval, rather flat. 
Antennz not quite half as long as body, comparative measurements as fol- 
lows: I, 0.06 mm.; II, 0.035; III, 0.145; IV, 0.06; V, 0.085; VI, 0.245 (0.05 plus 
0.195). Beak reaching second coxe, 0.25 mm. long. Cornicles cylindrical, twice 
as long as wide at base, faintly imbricated, 0.05 mm. long. 
Style conical, 0.08 mm. long. Length of body, 1.18 mm.; width, 0.52 mm. 
The thickened hind tibize bear a large number of small circular sensoria. 
NYMPHAL STAGES. 
For the male the nymphal stages were not observed closely, this 
form having been very rare on the cat-tails in 1916. From such 
observations as took place it appears safe to say that both males and 
fall migrants develop in about three weeks. The development of ovip- 
arous females was observed in 1916 on both Agen (/’rench) prunes and 
