1952] 
Feldman and Bailey — Corythucha 
97 
the abdomen. Clearing was continued until the last few 
segments became transparent. Depending on the maturity 
of the insect, considerable variation in the time of clearing 
was encountered. A somewhat teneral (incompletely pig- 
mented adult) female cleared sufficiently in 30 minutes 
whereas an older one required as much as three hours. The 
specimen was washed, stained with 5 percent acid fuchsin, 
dehydrated, and mounted ventral side up in permount on 
a microscope slide. 
Preparation of the valves of the ovipositor requires 
ten minutes. Abdomens from insects previously stored in 
70 percent alcohol, can be run up to 95 percent alcohol, 
then put into absolute alcohol, and clearing agent. With a 
pair of minuten nadeln mounted in needle holders, the 
valves are dissected and mounted on a microscope slide. 
II. Morphology of the abdomen and ovipositor 
The abdomen of the female consists of nine seg- 
ments with a much reduced tenth segment, represented by 
a pair of lateral plates and a single tergite. Snodgrass 1 
showed that in Anasa tristis DeGeer the sternum of the 
first segment is absent; the first ventral plate of the abdo- 
men is therefore the second sternite. This is also true of 
Corythucha. The dorsal aspect of the abdomen is flat but 
the ventral side is convex. Sternite VII is modified along 
its posterior medial border to form a single lobe, the sub- 
genital plate. Sternites vm, IX, and X are paired and modi- 
fied to form the ovipositor. 
In a typical case exhibited by Corythucha heide- 
manni Drake, the ovipositor comprises two fifths of the 
entire length of the abdomen, the pregenital segments 
making up the remaining three fifths (figure 18). The 
shape of the abdomen from the ventral aspect is elliptical. 
The posterior segments progressively diminish in size so 
that the terminal part of the abdomen tapers more or less 
to a rounded point. 
From the ventral view the upper pair of valves is 
valve one. These are symmetrical and possess a score or 
more ridges over the entire surface except the dorsal side 
1 1933. Morphology of the Insect Abdomen. Part II. The genital 
ducts and the ovipositor. Smithsonian Misc. Coll., 89(8): 1-148. 
