THE RED SPIDER ON COTTON. 11 
SECOND NYMPHAL STAGE (THE DEUTONYMPR). 
Description.—The deutonymph, which occurs only in the case of 
the female, resembles the protonymph except that it is larger and 
more elongate. In the advanced condition of this stage (PI. IT, fig. 4) 
it also resembles the adult female. Although pigmentation is intensi- 
fied as the mite approaches maturity, there is usually an absence of the 
characteristic reddish color. As the deutonymph approaches matu- 
rity it can be distinguished from the maturing male nymph, as the lat- 
ter is smaller, more cuneate posteriorly, and exhibits a tinge of amber 
or ferruginous. A series of measured deutonymphs averaged, 
length, 0.360 mm.; width, 0.218 mm. 
Duration of the deutonymphal period.—Perkins (1897) found that 
in Vermont an average of 2 days was required for the completion of 
the second nymphal stage under summer conditions. Ewing’s 5 
completed deutonymphal breedings averaged 2.6 days. The portion 
of this interval occupied by the quiescent. period 
(the ‘‘ Teleiochrysallis” of von Hanstein) is not 
clearly indicated in Ewing’s bulletin, but appears 
to be approximately 1 day. 
In the Batesburg investigations 25 colonies 
completed the second nymphal stage of the 
female. One deutonymph, the egg of which was 
deposited on September 27, required 13 days for 
its development. Exhibiting the other extreme, 
a few individuals of this stage matured in ap- 
proximately 1.25 daysin midsummer. The aver- 
age duration for the second nymphal stage during 
the active season is 1.9 days. Ta aie ey eae ane 
Habits.—The deutonymph is probably the _ time of second molt, still 
most voracious of the immature mites. It roves five (orignal) 
about considerably on its native leaf. Ewing 
(1914) records a well developed spinning ability on the part of the 
deutonymph. The first two stages are not adapted to traveling 
over the soil surface, owing to their frailty, but the last immature 
state is more hardy and active, and individuals are often capable 
of successfully establishing themselves after traversing considerable 
distances. This fact has been determined by ‘‘tanglefoot’’ tests, and 
by finding deutonymphs on cotton seedlings which were younger 
than the mites. 
Molting process—Upon two occasions, in the early morning, 
females issued from the second nymphal skin. The transverse 
split occurs practically as in the two preceding molts. In one in- 
stance, following a night minimum of 46° F., the morning was cool, 
and this condition doubtless worked to retard the duration of the 
process, which occupied nearly 4 minutes. The other observed 
