48 PLANT-BUGS INJURIOUS TO COTTON BOLLS. 
cotton plants. Field observations showed that whatever the nature 
of the attraction which is the basis of the occurrence, it is operative 
between the different species of Pentatomids as well as between 
individuals of the same species. 
As a result of this gregarious tendency it was found that of 467 
cotton plants examined on July 15, 1905, in one of the most heavily 
infested sections of the plantation at Tlahualilo, the infested plants, 
or those plants upon which there was at least 1 bug, numbered 91 
and averaged about 2 bugs per plant. There were therefore about 
five times as many of the insects upon the infested plants as upon 
the average of the plants examined. A further concentration of 
these bugs was observed on the individual bolls. Of 100 bolls upon 
which one or more of the bugs was feeding 52 were found to have 
from 2 to 5 bugs each and 48 only 1 bug each. In all, there were 
175 bugs feeding on the 100 bolls. 
FLIGHT. 
In September, 1904, conchuelas in the field showed themselves 
capable of only short flights, about 25 feet being the maximum dis- 
tance attained by any one effort observed. In July of the following 
year observations showed these insects to be strong fliers. Gentle 
winds have little effect on the flight of the insects, as they seem to fly 
as often against as with the wind. Many of the insects have been 
observed to fly as far as the eye could follow. In one instance when 
lost to view the specimen was about 50 feet above the ground and 
gradually rising higher; in another case a specimen disappeared 
from view without rising higher than 15 or 20 feet. 
The numbers of the insects in any given locality are subject to 
rapid changes owing to their flying propensities, but extensive 
migrations are always traceable to the need for a fresh food supply. 
SEASONAL HISTORY. 
INCREASE AND DECREASE IN NUMBERS DURING THE SEASON. 
Previous to the season of 1903, as far as can be learned, the con- 
chuelas attracted no particular attention as cotton pests in the 
Laguna district of Mexico. For the information here presented 
concerning the seasonal history of these insects in 1903 and 1904 
the author is indebted to Mr. John Conduit, resident manager of the 
Tlahualilo cotton plantations, who, owing to the immense tract of 
cotton grown under his supervision, gives particular attention to 
cotton pests, and in addition to personal examinations in the fields 
directs the "bosses" of the various parts of the estate to send in to 
the office specimens of insects taken on the cotton plants, with 
information concerning their abundance. The bosses in their turn 
make examinations and send dozens of laborers into the various 
