34 PLANT-BUGS INJURIOUS TO COTTON BOLLS. 



laboratory conditions. Fortunately the natural enemies of the insect 

 and probably also its greater activity in the field materially lessen 

 the average duration of adult life below that which was found to 

 obtain in the laboratory. A cage test in a cotton field failed to give 

 positive evidence regarding normal longevity of the adults on account 

 of the fact that the amount by which the insects' lives were short- 

 ened through their attempt to escape can not be estimated. Seven- 

 teen specimens which became adult between July 25 and July 31 

 were confined in a wire cage placed over a cotton plant bearing a 

 dozen bolls and many blooms and squares. The cage rested on 

 cheese cloth in order to facilitate the finding of dead bugs. On 

 August 27 Mr. John Conduit, of Tlahualilo, noted that 10 live adults 

 could be seen and no dead ones. On September 2 Mr. Eobert 

 Vaughan, of Tlahualilo, noted that there were 5 dead specimens, 

 and on October 15 another dead specimen was observed. Live 

 adults were noted as follows: September 10, 2; September 20, 1; 

 October 9, 1; October 12, 2; October 15, 1; October 18, 1; October 

 20, 0; October 24, 0; October 31, 0. The number of adults noted 

 on each date simply includes those which could be seen from out- 

 side the cage. It is not impossible that some of the insects found 

 an opportunity to escape, as of the 17 insects only 7 can be definitely 

 accounted for. ■ The results show that 5 died in from 32 to 37 days, 

 1 in between 45 and 50 days, and 1 in between 78 and 83 days after 

 reaching the adult stage. The sex of the specimens used in this cage 

 test was not recorded. 



Length of life when de'prived of food. — Without food the life of adult 

 conchuelas is very short in summer temperatures: On July 21, 28 

 adults — 12 females and 16 males — taken on cotton plants at 11.30 

 a. m. were placed, at 12.30 p. m., without food, in a wire cage whose 

 dimensions were 2 by 1 by 1 foot. The insects were very restless 

 and flew almost continuously during daylight from one side to the 

 other in the cage. In 33 hours from the time they were last fed 

 only 7 of the 28 were alive and in 48 hours all were dead. In a 

 second experiment 17 adults — 8 females and 9 males — taken on 

 cotton plants July 22 at 5 p. m. were placed, at 6 p. m., in a 

 lantern globe loosely filled with soft, crumpled paper to prevent the 

 insects from exhausting themselves by attempting to fly. Twenty- 

 six hours after being deprived of food 9 of the 17 were dead and 41 

 hours after being deprived of food the last surviving specimen was 

 noted as dying. The daily mean temperature at Tlahualilo at the 

 time of the foregoing tests in the starvation of the conchuelas was 

 between 75° and 80° F. On September 20, two specimens of this 

 species were collected in western Texas and confined in separate pill 

 boxes without food. These two specimens lived 5 and 6 days, respec- 

 tively. The length of life without food is clearly dependent upon 



