65 



PLACE OF EGG DEPOSITION. 



The location of egg punctures, while variable, still shows some 

 selection on the part of the weevil. This may be due partty to the 

 form of the squares and partly also to the size of the weevil, but what- 

 ever the explanation the fact remains that in a majority of cases the 

 egg puncture is made on a line about halfway between the base and 

 tip of the square. When so placed the egg comes to rest either just 

 inside the base of a petal or among the lowest anthers in the square, 

 according to the varying thickness of the floral coverings at that 

 point (PL I, fig. 3). Punctures are very rarely made below this line, 

 though they are sometimes made nearer the tip. Almost invariably 

 the egg puncture is started through the calyx in preference to the 

 more tender portion of the square, where the corolla only would need 

 to be punctured. The reason for the choice of this location may be 

 found under the subject of the "Relation of warts to oviposition," on 

 page 69. 



With bolls no selection of any particular location has been found, 

 but eggs seem to be placed in almost any portion. PL X, fig. LI, 

 shows the egg deposited inside the carpel. 



POSITION OF THE WEEVIL WHILE PUNCTURING FOR OVIPOSITION. 



W T hile engaged in making egg punctures the favorite position of 

 the weevil is with its body parallel to the long axis of the square and 

 its head toward the base of the same. The tip of the weevil's body 

 is thus brought near the apex of the medium size square. Having 

 selected her location, the female takes a firm hold upon the sides of 

 the square and completes her puncture while in this position. It may 

 be that the position described is especially favorable for obtaining a 

 firm and even hold, and this may have something to do with the reg- 

 ularity with which it is assumed. If so, the apparent choice of this 

 location for the puncture is only partially explained, since it has been 

 often shown that weevils can puncture and oviposit successfully in 

 almost any portion of the square except its very tip. 



Undoubtedly there are other reasons than those of mere conven- 

 ience which have so impressed themselves upon the inherited experi- 

 ence of the weevils as to lead them to the choice of this position and 

 the consequent location of the punctures and eggs. Most apparent 

 of these reasons, and probably also most important, is the advantage 

 which this location affords in the protection of the egg and the young- 

 larva developing from it against the attacks of natural enemies as 

 well as from the injurious effects of drying and decay. 



This protection is readily explained by several facts. The place 

 chosen is through the thickest and toughest portion of the floral 

 envelopes through which the anthers can be reached, since the thick- 

 est parts of both calyx and corolla are toward their bases. More 

 21739— No. 45—04 5 



