72 PLANT-BUGS INJURIOUS TO COTTON BOLLS. 
is believed that the data given in connection with the study of 
individual capabilities of the conchuela will be useful in the deter- 
mination of the expense a cotton grower can afford to incur for hand- 
picking of the conchuela and other Pentatomid bugs when appear- 
ing in threatening numbers. It may be said summarily that the 
practicability depends on the available abundance of cheap labor 
and on the acreage of cotton that it is desired to treat. 
OTHER METHODS OF COLLECTING BUGS FROM COTTON PLANTS. 
In addition to collecting by hand, a test was made of the possibility 
of collecting the immature conchuelas by jarring them into a piece 
of canvas or cloth placed around the stalk of the infested cotton 
plants. Certain modifications of this method might be useful where 
the numbers of immature bugs on each plant is large, or where 
machines, such as have been devised but proven unsuccessful for 
the collection of the boll weevil and bollworm, might give good 
results in the collection of both 
nymphal and adult stages of the 
plant -bugs. 
CONTACT INSECTICIDES. 
Adult Pentatomid bugs, in general, 
are known to be little affected even 
by strong solutions of contact insecti- 
cides. For ordinary field treatment 
insecticides, regardless of efficiency, 
Fig. 10. — The grain bug (Pentatoma sayi): . . . -, « . -, 
Nymph, first instar. Enlarged 2i di- are impractical for use against such 
ameters. (Original.) insects as the conchuela. Their use 
might, however, be advisable under such conditions of excessive 
infestation as have been described as resulting from the migration of 
nymphs in 1905 at Tlahualilo. As suitable materials for making and 
applying kerosene mixture were not available, a test was made of 
cottonseed-oil soap solution, using one-half pound of soap in 4 gallons 
of water. This was found to destroy nymphs when thoroughly 
sprayed, but only 3 or 4 per cent of the adults succumbed to the same 
treatment. 
TRAP CROPS AND ATTRACTION TO LIGHTS. 
Early in the season, before bolls are put on by the cotton plants, 
a few mesquite bearing heavy crops of beans might serve a useful 
purpose by attracting the conchuelas. For good results it would be 
necessary that the development of the insects be carefully watched 
and treatment applied before the first of the spring nymphs reach 
maturity. Unless proper attention can be given, however, as has 
been indicated in the discussion of preventive measures, it is inad- 
