85 



THE ACT OF OVIPOSITION. 



The general process of making punctures has been described pre- 

 viously under the topic of "Food habits" (p. 50), and will therefore 

 not be repeated here. Having completed the formation of the egg 

 cavit}^, the female withdraws her proboscis and turns end for end. 

 She depresses the tip of her abdomen and locates therewith the open- 

 ing to the cavhy by feeling or scraping around. In a majority of 

 cases the opening is readily found, but sometimes it is not. Then the 

 female seems often to lose all sense of locality, but continues scraping 

 with the tip of her abdomen. If she is still unsuccessful, she turns 

 and continues the search by means of the antennas, just as in the pre- 

 liminaiy 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 proximit}^. 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 tip of the abdomen, the ovipositor 

 is first protruded to the bottom of the cavit} r , in which it appears to 

 be firmly held in position by the two terminal papillse and the power 

 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 The ovipositor is then withdrawn, and just as the tip 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 (PI. XV, fig. 66). 



TIME REQUIRED TO DEPOSIT AN EGG. 



Observations upon this point were very conveniently made by con- 

 fining females upon squares from which the involucres had been 

 removed. A plain glass cover allowed accurate observations, which 

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

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

 two points especially noted. 



