116 INSECTS INFESTING THE PEAR TREE. 



the course of the central part of the branch. By this means 

 the vessels which convey the ascending sap is cut off, and that 

 part of the branch above the place where the insect is located, 

 withers and soon becomes dead wood. 



The larva assumes the pupa form in its burrow, and the 

 perfect insect appears early in Summer. 



The perfect beetle (Fig. 89) measures about one and one 

 quarter lines, or a tenth of an inch, in length, and is of a deep 

 uniform brown color. 



Fig. 89. — Pear-tree Scolytus, natural size and en- 

 larged — color, brown or black. 



For the destruction of this insect, it has been rec- 

 ommended to cut off and burn the infested limbs. 

 This should be done earlier than the month of April, 

 otherwise the beetles will have completed their trans- 

 formations and made their escape. 



I have not found this insect in this State, but from speci- 

 mens of branches sent me for examination, there can be no 

 doubt of the presence of this beetle, or a closely allied species. 



Remedy. — Prune, as above described, and use No. 37 on the 

 branches as soon as the beetle appears, which is in the latter 

 part of July. The branches, etc., may be sprayed with Xo. 

 4, or Nos. 5 or 7. 



CHAPTER LIX. 

 The Branch and Twig Burrower. (Cal.) 



(Polycaon confcrtus. — Leconte. ) 

 Order, Coleoptera ; Famil}^ Ptinid^. 



[An elongate pitch-colored beetle, about half an inch in 

 length, burrowing into the branches and twigs of the apple, 

 pear, cherry, almond, apricot, peach and olive trees, and also 

 into grape canes.] 



In June, 1881, Mrs. E. R. Thurber, of Vacaville, sent me 

 some olive branches (Fig. 92, Plate 1) which were infested by 

 this beetle. In the Fall of 1881, grape cuttings (Fig. 93, Plate 

 1) were sent me from Sonoma County, with a beetle, which 



