Dec. 15 ,1925 Observations on a Cotton Insect New to the United States 1143 
is also very active and is usually the smallest stage to be found upon 
the plants under field conditions. The nymphs of the third stage, 
as well as the few nymphs of the second stage which have been 
observed above the ground, have a habit of dropping to the ground 
when the plant is disturbed and quickly hiding themselves in crevices 
in the soil. For this reason it is very difficult to collect them in 
numbers. 
Duration of the Third Stage 
Nine records of the third stage have been obtained, the period 
varying from 4 to 18 days. The total time covered by the nine 
records was 85 days, giving an average period of 9.44 days. 
FOURTH-STAGE NYMPH 
The nymph of the fourth stage is decidedly larger than that of 
the third, the insect now having attained a length of slightly more 
than one-fourth of an inch, exclusive of the antennae, which are about 
half as long as the body (fig. 1, E). Although the general color of 
the body is still bright red, the segmentation is now distinctly marked 
by delicate white lines on the dorsal surface. The abdominal 
surface is much paler than the dorsal, and the segments are joined 
by bright red lines. The wing pads now appear for the first time 
as two heavy black spots at the rear end of the thorax, and the legs 
and antennae are almost black. The nymphs of this stage are rather 
numerous in the field and can be collected without difficulty, since 
they are not nearly so shy as those of the third stage. 
Duration of the Fourth Stage 
Eleven records of the fourth stage cover a total of 110 days, and 
give a general average period of 10 days. These periods range from 
4 to 19 days. Evidently the midsummer average period is about 4 
or 5 days for this stage. 
FIFTH-STAGE NYMPH 
In the fifth stage the sexes differ considerably; so much so that at 
first they were thought to be two separate stages. The female 
nymph of the fifth stage is considerably larger than the male nymph 
oi the same stage owing to the much larger abdomen, which makes 
the wing pads appear proportionately shorter. The fifth-stage male 
nymph resembles the adult much more closely than does the female, 
since the abdomen is not so large and the wing pads therefore lie 
flat along the back, appearing to be longer in proportion to the size 
of the abdomen (fig. 2, A). 
The length of the body in the fifth stage averages about three- 
eighths of an inch, exclusive of the antenna?. The wing pads are 
now about twice as large as they were in the |ourth stage. The 
general coloration is much the same as before except that the seg¬ 
ments of the body are very distinct, the dividing lines having become 
much more prominent. 
