68 PLANT-BUGS INJURIOUS TO COTTON BOLLS. 
which might prove disastrous to cotton. Various grains, however, 
will also bear watching for the purpose of locating and treating cases 
of excessive multiplication. In a previous paper, dealing with the 
conchuela at Barstow, Tex., in 1905, the author considered at length 
the subject of the control of this insect in the alfalfa fields, a brief 
recapitulation of which will suffice in this connection. 
At both Tlahualilo and Barstow, in 1905, were notable instances of 
the development of enormous numbers of the conchuela in alfalfa 
fields. At the former place the bugs derived their entire food supply 
from the stems and leaves of the plants, while at the latter locality 
more than ordinary multiplication occurred only where an attempt 
was made to produce a crop of seed before the middle of August. 
The advantage is in favor of the crop used only for forage, for the 
shorter time between the cuttings permits of the maturity of but 
comparatively few of the insects, and the problem to be solved consists 
of the treatment of the nymphs and the prevention of their migration 
to neighboring cotton fields. An uncut border a few feet in width 
around an infested alfalfa field will serve to trap the crawling insects 
which then may be destroyed by spraying with a strong solution of 
kerosene emulsion. If heavy infestation be restricted to limited 
areas of the field, hand picking of the adults by children or other 
cheap labor and destroying the nymphs by spraying may be advis- 
able. Gasoline blast torches have been used for destroying the con- 
chuelas and may sometimes be useful under circumstances where no 
vegetation except weeds or other noxious plants will be affected. 
The longer period required for the maturity of a seed crop of alfalfa, 
together with the abundance of favored food (alfalfa seed), affords 
most favorable conditions for the development of countless numbers of 
the conchuela. Great care should be exercised, therefore, wherever 
this pest is likely to occur in destructive numbers, in selecting a 
season of the year when a seed crop of alfalfa can be grown profit- 
ably and without disadvantage to cotton or other neighboring crops. 
In western Texas an attempt to produce a seed crop has been shown 
by past experience to be practicable only after the middle of August, 
when the destructive season of the conchuela has passed. 
Field Measures. 
hand-picking. 
Extent of experiments and methods used. — In cooperation with Mr. 
J. P. Conduit and Mr. J. A. Vaughan, manager and assistant manager, 
respectively, of the Tlahualilo plantation, experiments were conducted 
in July, 1905, for the purpose of determining the utility of hand-picking 
as a practical remedial measure against the conchuela. In this work 
many native boys ranging from 9 to 15 years of age were employed. 
