THE SIX-TOOTHED BARK BORER. 171 



The other beetle, Polygraphia pubescens, is larger than 

 P. chalcographies, reaching T 1 ^ inch in length. It comes nearer 

 the pine and ash bark beetles than any of the beetles previously 

 named here. Fowler describes it as very rare and gives 

 Scarborough as the locality. It is a polygamous species found 

 in the bark of spruce. A common name for it is the four-eyed 

 spruce-bark beetle, this name being given because each of its 

 two eyes is almost separated into two halves ; this is an excellent 

 recognition-character for the genus, but a very good hand-lens 

 is required to see it. Another good character for our species 

 is the rimey or frosted appearance of the wing-covers, due to 

 a series of pale-coloured scales. The antennae are also char- 

 acteristic but they require a microscope, and all through these 

 notes I have aimed at characters which need only a pocket-lens 

 at most. 



P. pubescens is polygamous, and the brood-galleries are chiefly 

 in the bark ; the larval galleries run in different bast-layers, and 

 therefore a complete picture of a brood-gallery system is not seen 

 on the inner surface of a peeled-away piece of bark, but only 

 isolated streaks and scratches of mother-galleries and larval 

 galleries. This beetle, while chiefly a spruce-infesting form, 

 has, on the Continent, been taken on other conifers. 



Amidst the heavy fellings all over the country conditions 

 are favourable for finding P. chalcographus, and perhaps P. 

 micrographus and P. poligraphus. I am very willing to examine 

 doubtful specimens, and would record, in the Transactions 

 of the Society, any discoveries. It will have been noticed 

 that all the species dealt with here are polygamous species, 

 and the forester has therefore a guide, from the pattern of 

 the workings, as to whether or no the species is the one 

 being sought. 



