Nov. 13,1916 
Rosy Apple Aphis 
339 
MALE 
DESCRIPTION 
As with the fall migrant, the earlier instars of the male are similar 
to those of the wingless viviparous form; only the fourth and fifth instars, 
therefore, are here described. 
Fourth instar (pupa). —Morphological characters. Antennae with the following 
measurements: Segment III, 0.416 mm.; IV, 0.32 mm.; V, 0.216 mm.; VI, (0.092 
plus 0.504 mm.). Segment III with about 58 sensoria, IV with about 27, V with 
about 7. Cornicles about 0.284 mm. 
Color characters: Somewhat similar to those of the spring pupa. 
Firth instar (adult) (PI. 21, B).—Morphological characters. Antennae with the 
following average measurements: Segment III, 0.728 mm.; IV, 0.462 mm.; V, 0.302 
mm.; VI, (0.113 plus 0.657 mm.). Cornicles 0.304 mm., slightly thicker than those 
of the migrants. Head without tubercles above, prothorax with very minute lateral 
tubercles, sometimes with none visible; lateral abdominal tubercles very small; 
last two segments of abdomen without tubercles above as in the spring migrant. 
In this respect the male is like the fall migrant. 
Color characters: Similar to those of the fall migrant. In many cases the large 
central abdominal spot is broken into a number of irregular bands and the crossband 
caudad of the cornicles is often divided, the total forming a series of cross stripes on 
the abdomen. 
production 
As has been noted previously, the males, when produced by a mother 
also bearing fall migrants, were usually the last progeny of the mother. 
The few mothers which produced only males were sisters of fall migrants. 
In this way the production of males commenced at about the same time 
as did that of the oviparous females. 
nymphal stages 
. The period spent in the immature stages varied from about 20 to 25 
days. No general statement can be made as to the duration of the 
various instars, since these varied greatly among the individual insects. 
migration 
When mature, the males leave the plantain, flying to apple. If the 
oviparous females are not fully mature the males usually settle down 
beside them and feed. * 
OVIPAROUS FEMALE 
description 
First instar. —Morphological characters. Antennae with the following measure¬ 
ments: Segment III, 0.144 to 0.16 mm., average 0.148 mm.; IV, (0.048 plus 0.184 
mm.) to (0.056 plus 0.216 mm.), average (0.049 plus 0*196 mm.). Cornicles 0.056 mm. 
Color characters: Very pale greenish yellow with brown eyes. 
Second instar. —Morphological characters. Antennae with the following measure¬ 
ments: Segment III, 0.136 to 0.16 mm., average 0.142 mm.; IV, 0.064 to 0.08 mm., 
average 0.07 mm.; V, (0.056 plus 0.216 mm.) to (0.064 plus 0.248 mm.), average 
(0.059 plus 0.232 mm.). Cornicles 0.08 mm. 
Color characters: Slightly darker than in the first instar. 
