41 



The tunnels made by the larva' after hatching may branch off in any 

 direction up or down a limb or at right angles to its main axis. They 

 are not always so easily traceable as in the piece of apple twig illus- 

 trated, being sometimes very irregular in shape, running in all direc- 

 tions, crossing and recrossing in hopeless confusion. The average 

 length of the burrows is a matter of only 1 or 2 inches, the largest seen 

 measuring only 2J inches (47 mm ). At their beginning they measure 

 about half a millimeter in width, and at their end where the pupal cell 

 is formed lj mui to a little more than 2 mm . The length of the pupal cells 

 is 5 or 6 mm . They are rather regular oblong oval in shape (see fig. 

 26, a and c.) 



The larva completes its growth toward the end of the warm season 

 and with little doubt hibernates in this stage, undergoing transforma- 

 tion to pupa and thence to imago in March and April respectively. The 

 beetle makes its escape through a round hole which it cuts out through 

 the bark by means of the mandibles at the end of its rostrum or pro- 

 boscis. The diameter of these holes is from 1 to a little more than t mm . 

 These holes are figured natural size (fig. 20,/). 



The native species of true weevils (Rbynchophora exclusive of Scoly- 

 tidre) produce as a rule a single generation annually, and the present 

 species is probably no exception. 



Professor Piper has kindly furnished for publication in this connec- 

 tion his notes bearing upon the biology of the species, which supplement 

 our own and render the account more complete. These notes include a 

 brief description of the egg, an account of oviposition, the supposed 

 correlation of fungous disease and insect attack, feeding habits of the 

 beetles, and observations which show quite conclusively that the spe- 

 cies is single brooded : 



BIOLOGIC NOTES, BY C. V. PIPER. 



The egg. — Length, l mm ; width, i mm ; ovoid, yellowish-white, smooth, shining. 



Ovipositing habits. — The eggs are laid singly in horizontal holes hnrrowed in the 

 bark to the depth of about l mm . Usually from 12 to 25 of these holes are made in a 

 more or less circular area 6-10 m::: in diameter; but, in some cases at any rate, eggs are 

 not laid in all of them. The beetle usually requires half an hour or longer to burrow 

 each hole and two minutes in which to deposit the egg. In one case which was 

 watched the beetle burrowed first for twenty minutes, then turning around as if 

 on a pivot she tested the hole with her ovipositor. Apparently it proved too shallow 

 and she turned sharply about and burrowed for twenty-one minutes longer. At the 

 end of this time she turned about as before and immediately deposited an egg at 

 the mouth of the hole. Again turning she pushed the egg in with her beak, and 

 then flew away. 



In another instance the beetle burrowed for thirty minutes and then laid her egg 

 in the burrow exactly in the same manner as above described. 



Apparently the different egg cavities in each group are burrowed at different 

 times; at least in all the cases observed the beetle went away after digging one 

 cavity and laying her egg therein. 



Mr. D. A. Brodie reports that he several times saw the beetles burrow holes and fly 

 away without depositing eggs therein. These observations, taken in connection with 



