THE CONCHUELA. 



45 



this experience it is certain that in the cotton fields in clear summer 

 weather fully 90 per cent of the conchuelas are visible to the observer 

 from a standing posture and without moving any part of the plant. 

 It was a rare occurrence, when making records of the kind indicated, 

 that any additional specimens of these insects were found by using 

 the hands to open up the plant. Only a few instances have been 

 observed where the adult conchuela has been entirely or almost en- 

 tirely hidden by the bracts of the cotton boll on which it was feeding. 

 When feeding on a boll these insects generally occupy a position on 

 the upper half. When resting, during bright sunlight, they are com- 

 monly observed in a conspicuous position on the cotton boll or on the 

 upper surface of the leaves. The resting in the sun is usually observed 

 during the forenoon. 



Proportion of time adults spend in feeding. — In the determination of 

 the amount of damage an individual conchuela is capable of inflicting 

 in a cotton field it is important to know what part of its time it is 

 engaged in feeding on cotton bolls. Observations were conducted 

 both in the laboratory and in the field, and the results are summarized 

 in the following tables: 



Table XVII. — Feeding records on the conchuela in the field, 



Mexico, July 22, 1905. 



Tlahualilo, Durango, 



Hours of observation. 



Number of ob- 

 servations. 



Number of con- 

 chuelas feeding 

 on bolls. 



Number of con- 

 chuelas crawl- 

 ing or resting 

 on plants. 



Per cent feed- 

 ing on bolls. 





251 

 66 



142 

 51 



109 

 15 



56 



1 p. m. to 5.30 p. m 



77 









317 



193 



124 



66 







Table XVIII. — Laboratory feeding records on the conchuela. Lot A,0' Series L, Tla- 

 hualilo, Durango, Mexico, July 20-22, 1905. 



Hours of observation. 



Number of ob- 

 servations. 



Number of con- 

 chuelas feeding 

 on bolls. 



Number of con- 

 chuelas not 

 feeding. 



Per cent 

 feeding. 



6.30 a. m. to 8.30 a. m 



9 a. m. to 12 m 



1 p. m. to 5 p. m 



5.30 p. m. to 7 p. m 



8 p. m. to 10 p. m 



115 



72.4 

 45.6 

 49.5 

 69.8 

 89.8 



Table XIX. — Laboratory feeding records on the conchuela. Lot A, Series IT, Dallas, 



Tex., September 4-8, 1905. 



Hours of observation. 



Number of ob- 

 servations. 



Number of con- 

 chuelas feeding 

 on bolls. 



Number of con- 

 chuelas not 

 feeding. 



Per cent 

 feeding. 



6 a. m. to 12 m 



47 

 24 

 24 



8 

 9 

 15 



37 

 15 

 9 



17 



1 p. m. to 6 p. m 



37.5 



7 p. m. to 10 p. m 



62.5 







a Collected in cotton fields in Tlahualilo between July 6 and 10. 



