I9IO- FoRBEvS. — Scolytidac in Irish Focsiry* 91 



Compared with the Pine Beetle all other species of bark 

 beetle are comparatively harmless. On recently transplanted 

 trees, or such as are growing under unfavourable conditions, 

 it sometimes happens that the following may be regarded as 

 injurious : — Pityogencs bidentatus, a small black poh'gamous 

 beetle, the male of which carries two teeth on its wing-cases ; 

 Cryphaliis abietis, one of the smallest of the Scolytidae, and 

 frequently found on Silver Fir, Douglas Fir, Spruce, &c. ; and 

 Hylastes ater, probabh' the largest species found on coniferous 

 trees, and breeding on the roots and lower parts of the stem 

 of sickly trees, or on felled stumps. The damage inflicted b}' 

 any of these may prove fatal when assivSted in their attacks 

 by drought, unsuitable soils, and general debility due to 

 recent transplanting. On perfectly healthy trees they are 

 never the cause of serious injur}', the principal reason being 

 thai an attempt to bore galleries in vigorous trees is at once 

 checked by a flow of sap or resin, and the beetles must either 

 retire or become drowned in the fluid. Of the above, Pit^'ogenes 

 is probably the most widely distributed, and may be found in 

 any pine plantation in the tops or branches of felled trees. 

 Cryphahcs abietis is plentiful in Wicklow, but is not recorded 

 in the list referred to above. Other species commonly met 

 with are — Hylastes paUiahis in Spruce, Inarch, and other logs of 

 conifers ; Hylesium fraxini in Ash in a dying condition or 

 recently felled timber ; PhlaeophtJiorus rhododactyl7is\\\ Gorse ; 

 none of which can be considered injurious to healthy plants. 



Of the rarer Scolytidae, the v^riter has found PityophtJionis 

 piibesecns in Scots Pine near Oughterard, in Galway ; and 

 Hylesinus crenatus^ the largest of all bark beetles, in Ash 

 trunks in Tipperary. The latter was identified by its mother 

 and pupal galleries (Plate 2) and, although hitherto unrecorded 

 for Ireland, there can be no doubt that it exists. 



From the complete list of bark beetles recorded in Ireland, 

 it would appear that several species common in England are 

 absent, although the Elm-bark Beetle is perhaps the onl}' 

 remarkable omission. A careful search might, however, lead 

 to the discovery of several which have so far been unobserved, 

 as the difficulty attending observations of this family generally 

 are much greater than in the case of insects spending their 

 entire existence as imagos in the open air. 



Avondale, Co, Wicklow. 



A 2 



