36 BULLETIN 918, U. 5. DEPAETAIEXT OF AGFJCTXTrTJ:. 
been accumulated along this line, due to the nocturnal habits of the 
moth and the fact that in Mexico it was so generally distributed that 
no uninfested isolated fields were found. 
The average duration of the moth stage in captivity is about 14 
days. If the moth flies only a short distance before coming to a rest, 
it would appear certain that it may again proceed for another short 
distance. If there were nothing to influence the direction of its 
flight, it might fly in any direction and as likely as not return to its 
original starting point: but if the direction of the flight is influenced 
by the wind, as it was in our observations, it would fly with the wind, 
and where there is a prevailing wind from one direction the moth 
would be earned in the same general direction farther and farther 
from its starting point and might cover a considerable distance 
before dying. In the eradication work in Texas a 5-niile non- 
cotton zone around infested territory is used to prevent dispersal 
by flight, and it is thought this zone is reasonably safe. The moths 
have seclusive habits, and frequently hide in cracks, crevices, and 
dark corners. At the railroad stations in the Laguna cars stand 
upon the side tracks within a few yards of the cotton fields for days 
or even weeks at a time while being loaded and unloaded. Trains stop 
for long periods of time near the fields to unload supplies, and when 
these stops are made at night, when the moths are flying about, it is 
- -sible that some of the moths might secrete themselves in the cars 
and later be carried to distant points. There is the same danger, though 
to a lesser degree, in vehicles passing cotton fields along the roads. 
carriage of tarvj: by water. 
Cotton plants with bolls attached were often seen floating down 
the Rio Nazas when it was at flood stage, and old bolls are carried long 
distarces when fields are overflowed. Some experiments were made 
at Dr. W. D. Hunter's suggestion to determine how long larva? could 
survive exposure to water. Free larva? with no protection whatever 
pupated and produced moths after being in water in tubes for 44 homs. 
Larvae survived for several days after being in water longer, but 
none produced moths. Larvae in cocoons survived 72 hours in water 
in tubes and free larva? placed in pill boxes perforated with a needle 
produced one adult after S days' submergence in a pitcher. Pupa? 
did not survive as long as larva?. Old bolls picked in January. 191 S. 
and stored in the laboratory till April. 1919. were submerged in 
water and left floating on the surface of water in a trough. Larva? 
pupated and produced adults after 7 days in both instances, but no 
adults emerged after 11 days in either case. 
Several plants containing green bolls heavily infested were placed 
in the river and tied so that they could not float away. When there 
- s enough current in the river to keep the plants floating at the 
end of the string the bolls were all washed away at the end of 4 to 5 
days. When there was no current the plants sank to the bottom 
and all the larva? were found dead in 3 days. It is quite likely, however. 
