67 



as in the preliminary examination of a square before beginning a 

 puncture. 



In many cases females were noticed to actually place the tip of the 

 proboscis within the opening of the cavity without seeming to be 

 aware of its proximity. When the cavity has been found again by 

 the antennal senses, the female invariably enlarges it before turning 

 again to insert the ovipositor. If the search with the antennas does 

 not prove successful, the female will make another puncture in the 

 same manner as at first, appearing to know that no egg has yet been 

 placed in that square. 



After locating the cavity by the tij) of the abdomen, the ovipositor 

 is first protruded to tlie bottom of the cavity, in which it appears to 

 be firmly held in position by the two terminal papillae and the I30wer 

 of enlarging the terminal portion of the ovipositor. Slight contrac- 

 tions of the abdomen occur while this insertion is being made. In a 

 few moments much stronger contractions may be seen, and often a 

 firmer hold is taken with the hind legs as the egg is passed from the 

 body, and its movement may be seen as it is forced along within the 

 ovipositor and down into the puncture. Only a few seconds are 

 required to complete the deposition after the egg enters the opening 

 to the cavity. The ovipositor is then withdrawn, and just as the tip 

 of it leaves the cavity a quantity of mucilaginous material, usually 

 mixed with some solid excrement, is forced into the opening and 

 smeared around over the same by means of the tip of the abdomen. 

 This seals the egg puncture and the act of oviposition becomes com- 

 plete (PL X, fig. 39). 



TIME REQUIRED TO DEPOSIT AN EGG. 



Observations upon this point were very conveniently made by con- 

 fining females upon scpiares from which the involucres had been 

 removed. A jplain glass cover allowed accurate observations, which 

 were made to the fraction of a minute. The time required to com- 

 lilete the excavation and the time required to place the egg were the 

 two points especially noted. 



The time of making the puncture was noted in 115 instances, and 

 this was found to average 5:^ minutes. The time varied widely, being 

 from 1 to 13 minutes; the usual range was from 4 to 8 minutes. 

 From the time that the weevil began to puncture till the sealing of 

 the cavity the complete act of oviposition required in 103 instances 

 an average of slightly over 7^ minutes, ranging in time from 3 to 16 

 minutes. 



As these observations were made between October 7 and 23, the 

 periods given may be slightly longer than they would be in warmer 

 weather. However, various observations made in the field in mid- 

 summer agree very closely with the averages given. 



