THE OONCHUELA. 

 Table XXXI. — Cost of hand-picking of the conchuela. 



ni 



Date. 



Number of 



boys 

 employed. 



Total number 

 of hours. 



Number of 

 conchuelas 

 collected. 



Average 

 number of 

 conchuelas 



per boy. 



Expense of 

 picking. 



Number of 



bugs de- 

 stroyed for 

 each cent 

 of expense. 



1905. 

 July 12 



4 



14 



• 22 



25 



25 



20 



70 



110 



125 



729 

 6,200 

 5,400 

 1,500 

 1,600 



182 



428 



227 



60 



65 



$0.50 

 2.25 

 3.25 

 3.50 

 3.50 



14.5 



July 13 



27.5 



July 14 



10. 6 



July 25 



4.3 



July 26 



4 









Summary... 



90 



450 



15,429 



171 



13.00 



11.+ 



On July 25 and 26 the work in the tabla to which the above data 

 refer was unsatisfactory, owing to incompetent supervision. Accept- 

 ing, however, 11.+ as the average number of bugs collected and 

 destroyed for each cent of expense for a total of $135 expended in 

 1905 for hand-collecting at Tlahualilo, it is estimated that approxi- 

 mately 180,000 of the insects were collected and destroyed. If each 

 of these insects at the time of its removal from the field had been 

 capable of causing one-half as great damage as the data under in- 

 dividual capabilities show to have been accomplished under condi- 

 tions of heavy infestation " the total loss prevented by this expendi- 

 ture would be equivalent to over $1,800. The profit ma}^ be con- 

 sidered, therefore, as about twelve times the investment. 



Length of time required for Jiand-picJcing.—^ugs may be collected 

 much more quickly on small or medium-sized plants than on large 

 plants. In examining plants for the purpose of obtaining data on 

 seasonal history the writer on one occasion examined and made a 

 record of the number of bugs found on 1,892 plants in 2^ hours. 

 Considering that the recording of the data occupied about the same 

 length of time as would have been necessary to collect the insects, it 

 would require about 6 hours at the rate given to collect the Penta- 

 tomids found in conspicuous positions on the plants in 1 acre. The 

 native boys engaged in picking the bugs at Tlahualilo averaged about 

 30 minutes to each 300 plants, or about 7 hours per acre. 



Practicability of Jiand-jpicking in the United States. — Wliile the per 

 diem cost of labor is much greater in the States of our cotton belt 

 than in Mexico, where the experiments recorded were undertaken, 

 this probably would be to a great extent (if not entirely) offset by 

 greater efficiency. Especially good results should be obtained when 

 hand-picking can be practiced under the direct supervision of the 

 owner or some other person materially interested in the cotton. It 



a Indi\4dual capabilities for damage have been shown to be greatest when infesta- 

 tion is lightest. 



