THE CANADIAN ENTOMOLOGIST, 97 



PLATYPUS W/LSONI — A NEW SPECIES OF PLATYPUS 



FROM BRITISH COLUMBIA (PLATYPODID.F:, 



COLEOPTERA) * 



BY t. M. SWA INK, 



In charge of Forest Insect Investigations, Entomological Branch, Ottawa. 



The species of Platypus described herewith is very abundant 

 and injurious on the southern half of the British Columbia coast. 

 Although mentioned in literature and not unknown to collectors, 

 it apparently has never been described. Its habits are those of 

 a true ambrosia-beetle; the adults excavate a cylindrical tunnel 

 from about six to fourteen inches in length through the bark and 

 directly, into the wood of large and small trunks, in small trunks 

 usually curving around the heart. A characteristic fungus always 

 found coating the walls, which are stained black thereby, serves 

 as food for the larva?, and to a lesser degree for the adults. Eggs, 

 larva? and adults are found free in the tunnels. The boring dust, 

 ejected in abundance from the tunnel entrance and lodged in 

 heaps in the bark crevices, is in the form of minute white splinters 

 (PI. VII, Fig. 1). It is readily distinguished from the meal-like 

 boring-dust of Gnathotrichus frequently found in the same trunks. 



It attacks all conifers of the British Columbia Coast, with the 

 exception of Thuya and ChanuEcyparis, but is most abundant in 

 Pseiidotsuga, Tsiiga, and Abies grandis. The species is abundant 

 on the coast as far north as Seymour Narrows and inland in the 

 south to Agassi/. 



Dying or badly weakened trees and freshly cut logs are usualh" 

 selected for attack, but standing trees with considerable green foli- 

 age are not infrequently affected. A tree showing the piles of 

 boring-dust of this species and of GnatJiothrichus is invariabh 

 beyond hope of recovery. These piles of boring-dust are frequently 

 seen on the blackened bases of trees injured by ground fire; in 

 such cases the beetles enter through the fresh tissue exposed 1)\' 

 cracks in the drying outer bark. The details of the life-histor>- 

 will be given elsewhere. The specific name is given in honour of 

 our colleague, Mr. Tom Wilson, of Vancou\'er. B. C, who first 

 collected the species in British Columbia. 



*Contribut!on from the Entomological Branch, Department of Agriculture, 

 Ottawa. 



March, UUti 



