TOMICUS BISPAR. 



261 



healthy saplings, which become diseased and die. The 

 presence of the beetles may be detected by 

 the borings, and the whitish bore-dust heaped 

 up at the foot of the plant. 



The beetle is very destructive in orchards, 

 and sometimes to young oak- saplings. 



d. Protective Rules. 



Unbarked orchard-props should not be 

 used, as it frequently happens that the 

 beetle finds its way from such props into 

 the fruit-trees. 



e. Remedial Measures. 



i. The entrance-holes to the burrows 

 should be smeared with tar. 



ii. All plants which have been attacked 

 should be removed and burned. 



iii. The beetles may be killed inside the 

 galleries with wire, and the bores blocked up 

 by wooden pegs. This method of treatment 

 is generally impracticable, but has been 

 adopted with success in orchards. 



B. SUBFAMILY HYLESININI. 

 Description of Subfamily. 



Head prominent and not concealed by the 

 prothorax, with a short and broad rostrum ; 

 antennae with a funiculus of 5 to 7 joints ; 

 thorax narrowed in front, uniformly punc- 

 tate on the back; first tarsal joint much 

 shorter than the other three together, the 

 third bilobed or heart-shaped (except in the 

 case of Potygraphu* pubescens, Er.) ; apical 

 declivity convex and without teeth ; under- 

 surface of the abdomen not abruptly flexed upwards. 



Most species breed in the bast and especially frequent 

 conifers ; a few make pupal chambers in the sap-wood. 



Fig. 121. Bui-rows 



of T. dispar, Fabr., 



in an oak-sapling. 



(Natural size.) 

 a Entrance - hole, 



usually under a 



twig. 



b Mother-galleries. 

 c Commencement of 



lateral galleries. 

 d Completed lateral 



galleries in which 



the larvae lie. 



