58 BULLETIN 416, U. S. DEPARTMENT OF AGRICULTURE. 
9-spotted lady-beetle (fig. 19) is probably most abundant. Its sea-_ 
sonal occurrence doubtless corresponds very closely with that of H. 
convergens, although our 
records of the latter have 
usually been somewhat 
earlier. 
One adult individual from 
infested cotton ate 31 adult 
red spiders in 24 hours. 
Occasional observations 
have been recorded of this 
Fic. 19.—The nine-spotted lady-beetle (Coccinella novemno- coccinellid feeding on red 
tata), an enemy of the red spider: Larva at left, adult at spiders in the field. At 
right. Muchenlarged. (Chittenden.) Batesburg the one record 
for incubation was 3 days Gn August) and for the pupal period the 
solitary record occupied the last 10 days of August. 
? 
LEPIDOPTERA. 
NOCTUIDAE. 
Alabama argillacea Hibn.—When the cotton leafworm caterpil- 
lars become abundant, usually in late September or early October, 
they devour every vestige of the 
cotton foliage, excepting the 
stalks, branches, and _ petioles. 
Consequently myriads of red 
spiders which are harbored on the 
leaves at the time of defoliation 
are eaten along with the leaf tissue. 
In this way the leafworm acts most 
effectively as a remedial agency 
against the mites. Thereisanaddi- 
tional consideration in this con- 
nection, namely, that those mites 
which are not actually devoured at 
the time of the defoliation are com- 
pelled to seek new hosts through 
migration. 
Fic. 20.—Knapsack sprayer suitable for spraying 
low-growing plants. (Quaintance.) 
APICAL SWARMING. 
At times of continued drought and heat the lower and earlier 
infested leaves of many plants become dry and unattractive to the 
red spiders, which travel upward or outward, seeking the apical 
leaves, that normally remain green longer. If the plant is heavily 
infested, a swarming horde of mites is often witnessed converging 
toward and concentrating at the apices of the branchlets. Upon 
