1919] 



Blackman — Notes on Forest Insects 



91 



differences beingVorrelated with the difference in breeding habits. 

 Hylurgops appears to be strictly monogamic. Typically the 

 brood-burrow consists of a simple, nearly straight longitudinal 

 chamber extending either downward or upward from the entrance 



Figure 1. Burrows of Hylurgops pinifex in bark of white pine. Note the 

 arrangement of the egg, either in niches or in grooves along the sides of the egg- 

 gallery. Three-fourths natural size. 



gallery (Fig. 1). Usually, just inside of the entrance there is a 

 short branch or alcove, seldom greater in depth than the length of 

 the beetle, which is used as a turning niche and also as a nuptial 

 recess (Fig. 1 ; Plate 4, fig. 3) . At or near the other end of the 

 fully completed egg-gallery there is likely to be a somewhat similar 

 recess which, however, instead of lying parallel to the surface of 

 the wood extends outward part way through the bark. It doubt- 



