1900] PLUM SAP-WOOD BEETLK. 69 



to be useful in killing ninety per cent, of the maggots when sprinkled 

 in quantity which would represent a fair field dressing. 



We have evidently, from the reports of the past three seasons, now 

 to look on this Pear attack as a thoroughly established broadscale pest, 

 which, if attended to rightly, and with co-overation by simultaneous 

 action from neirjhbounng growers, may be greatly checked ; but which, 

 if 7iot looked to, appears, from our experience, to be on the way to 

 establishment as a cause of serious loss. 



PLUM. 



"Splint" or Sap-wood Beetle. Scolytus pruni,B,a.tz. 



ScoLYTuspRUNi.— Beetle and wing, magnified ; line showing natural 

 length of beetle. 



On March 20th in the past season the following observations of 

 what proved to be attack of Scolytus pnini, known in Germany as the 

 Splint or Sap-wood Plum Beetle, were sent me from Barton-upon- 

 Humber by Mr. G. W. Mason : — 



" Yesterday I was in an orchard here, where the owner showed me 

 a Plum tree which he said was dying. The trunk of the tree was 

 almost completely stripped of its bark where it lay upon the ground. 

 Some of the branches were also being stripped in the same manner. 

 I noticed the tree (together with several others in the vicinity) was 

 perforated with countless little holes. On examination I found a small 

 white larva feeding on the fallen bark. I am sending you a piece of 

 bark with some of the larvae therein." — (G. W. M.) 



Mr, Mason noticed the great similarity of the infestation to that of 

 Scolytus rugulosus, or "Wrinkled Fruit-tree Bark Beetle,"" which is 



* For figures and description of this infestation, see my Annual Eeport of 

 Observations for 1895, pp. 76-79 ; also ' Handbook of Insects Injurious to Orchard 

 and Bush Fruits,' pp. 197-201. 



