8 4 
Journal of Agricultural Research 
Vol. XI, No. 3 
EGGS 
The eggs are polished black and are laid upon the twigs of Viburnum 
prunifolium. They are usually placed most thickly close around the 
buds, although when the plants are thickly infested they may be dis¬ 
tributed more evenly over the twigs. The eggs hatch sometimes during 
quite cold weather in the third week in March, but the insects produced 
from these first-hatched eggs are sometimes killed by frosts. Hatching 
continues until the early part of April. 
STEM MOTHER 
When first hatched, the stem mother is of a very dark greenish-brown 
color. The young aphids, on hatching, seek out the buds and begin 
feeding. Here they remain until the buds open, and when the flowers 
begin to open it is not uncommon to find them crowded down into the 
flower clusters. They feed upon the stems of the individual blossoms, 
and when the petals begin to show the presence of the aphids is often 
not noticeable. They also, however, feed upon the twigs and somewhat 
upon the leaves. 
First instar. —Color dark greenish brown, the abdomen lighter than the other 
parts of the body. Appendages black, as is also the head; abdomen with a few rows 
of darker spots. Antennae of three segments; segment III measuring 0.064 plus 0.08 
mm. Cornicles very short and tuberculate, being about 0.016 mm. long. 
Found feeding on the twigs of Viburnum prunifolium. 
Second instar. —Somewhat similar in color to the first instar, although of a more 
deep brown color rather than a greenish brown. Abdomen without apparent darker 
brown spots, but uniform brown. Appendages dusky to black. When first molted, 
the insects are an amber color. The empty skins are dusky. Antennae of four or 
five segments; segment III, 0.08 mm.; IV, 0.06 mm.; V, 0.4 plus 0.08 mm.; 
cornicles, 0.05 mm. 
Found in the same places as the first instar. 
Third instar. —Very similar in color to the second instar, although sometimes a 
little lighter. Antennae of five segments; segment III, 0,112 mm.; IV, 0.08 mm.; 
V, 0.064 plus 0.112 mm.; cornicles, 0.064 mm.. 
Found in the same places as the earlier instars and also crowding down into the 
expanding buds. 
Fourth instar. —Similar to the previous one in color. Antennae of five seg¬ 
ments; segment III, 0.16 mm.; IV, 0.08 mm.; V, 0.064 plus 0.112 mm,; cornicles, 
0.112 mm. 
Fifth instar (adult). —Color characters similar to those of the previous instars, 
but some of these forms are somewhat yellowish. Most of them, however, are a 
distinct reddish brown. Eyes deep brown, vertex dusky. Antennae dusky, with 
the distal segment and the first two segments darker than the others. Legs similar 
in color to the antennae, the tarsi and distal extremity of the tibiae dusky. Cornicles 
dark. Antennae of five segments; segment III, 0.208 mm.; IV, 0.112 mm.; V, 
0.064 plus 0.128 mm.; segments, particularly the distal one, distinctly imbricated, 
but without sensoria other than the usual ones. Cornicles 0.144 mm. long, without a 
distal flange, but with faint imbrications. 
Found on the leaves, twigs, and flowers of Viburnum prunifolium L. 
