20 BULLETIN 344, U. S. DEPARTMENT OF AGRICULTURE. 



All bolls were retained, and at the close of the experiments on 

 November 10 all were opened and the contents noted. This exami- 

 nation showed that 15 adults had emerged after observations were 

 stopped, 33 adults were alive in cells, 22 adults were dead in cells, 

 9 pupae were alive in cells, 4 larvse were alive in cells, and 3 larvae 

 were dead in cells. Thus it is seen that 22 adults emerged, 33 

 remained alive in the cells, and 22 died in them. 



The developmental period for the seven weevils which were 

 observed at the time of emergence varied from 17 to 28 days, with 

 an average of 21.4 days. In Texas the Thurberia weevils averaged 

 25 days in cotton bolls. They displayed the same tendency to delay 

 emergence some days after maturity but did not attempt to hiber- 

 nate in the cell as in Arizona. 



Many of the records point to the great irregularity of the devel- 

 opment in cotton bolls. In one case where the egg was deposited 

 August 13 a live pupa was found in the boll on November 10, or 

 a total of 58 days for incubation plus larval plus part of pupal period. 

 In another case where the egg was deposited October 1 a live larva 

 was found November 10, or a total of 40 days for incubation plus 

 part of larval period. When it is remembered that under the same 

 conditions adults were produced and emerged in as few as 17 days 

 after egg deposition, these records are all the more striking. 



The death of the adults due to proliferation is quite interesting. 

 Five were found which were quite evidently killed by this agency. 

 In these cases the weevils had formed more or less normal pupal 

 cells, but the growth of the tissue broke these and pressed the adults 

 to death. Of course, there was no way to determine how many of 

 the immature stages were killed by this phenomenon, but the num- 

 ber was probably quite high. 



IN THURBERIA BOLLS. 



The Thurberia bolls containing eggs secured in the different series 

 of weevils fed upon this food were placed on moist sand in tumblers 

 and an attempt made to rear adults. In such tests the bolls were 

 always as green and fresh as possible and were selected as seeming 

 best adapted for larval food. Early in the investigation it was quite 

 apparent that a single moistening of the sand in the tumbler would 

 not suffice to keep the boll fit for larval food through the develop- 

 mental period, so the sand was moistened frequently. In this way 

 what seemed to be the best conditions for development were secured, 

 but, in spite of this, the attempt was almost a total failure. 



Thirty bolls containing many eggs deposited from June 30 to 

 October 16 were observed, and only one weevil emerged from the 

 entire lot. This was a male which emerged October 31 from a boll 

 which had received an egg October 1, giving a total period from 



