6i8 FAMILY PLATYPODIDAE 



Crossotarsus fairmairei, Chap., var. wilmoti, Stebbing. 



Referenxe. — Stebbing (Diapus), Depart. Notes, i, 415. 



Habitat. — North- West Himalaya. 



Tree Attacked. — Ban Oak {Qucvcm incana). Jaunsar. 



Beetle.— The beetle resembles fairmairei. The colour is darker red, the thorax being 



entirely of this colour, as are the legs, with the exception of the tarsi, which are lighter brown. 



The front of the head is only very finely pitted in the male, but 



Description. strongly punctured in the female. The thorax is strongly constricted 



at the sides behind the middle and has no median line. The apical 



margin of elytra is concave in male, and in female truncate, with the outer edges produced 



into teeth curving inwards. The abdomen is concave behind in the female. Length, 5 mm. 



to 5.4 mm. Figs. 6, 6^7, pi. xlv, show this beetle side and dorsal view. 



The insect is to be found on the wing at the commencement of June at 

 elevations of 6,000 ft. It tunnels into the ban oak for 

 Life History. egg-laying purposes. The beetle appears to prefer trees 

 which are dead but not yet absolutely dry, and it bores 

 down through the thickest bark into the heart -wood, making circular tunnels, 

 the sawdust eaten out being ejected at the surface of the entrance-hole. A 

 tree attacked can be easily detected by the presence of these small heaps of 

 sawdust piled up on the outside bark. The tunnels may be quite straight 

 or curved slightly. Both male and female beetles are to be found in the 

 tunnel, and pairing probably takes place inside. The female insect appears 

 to live for some time after egg-laying is completed, finally dying in the 

 mouth of the tunnel and so blocking it to predaceous enemies. The eggs 

 are laid at the bottom of the tunnel, and the larvae feed on fungous growths 

 with which the walls of the tunnel are discoloured. The tunnels are as 

 much as 9 in. to 12 in. in length. This is all that is at present known about 

 the life history of this insect. 



As will be seen, the damage done is entirely to the timber of the 

 tree, since the sm.all portion of bast platypid beetles 

 "^i^Te^FoTst"''^ eat through on their way to the heart-wood is a 

 negligible quantity. When plentiful the beetles en- 

 tirely ruin the wood of a tree for timber purposes, and greatly reduce the 

 value of fuel stacks. 



When wood is badly attacked by these wood-boring beetles, the only 



safe method of destroying them and endeavouring to 



Protection and j^^^^^ ^^^.^ numbers in an area is to burn the whole of 



Kemedies. ^ , ,_. ,11 , 1 



the infested timber and fuel. The actual hole or tunnel 



in the wood is, as we have seen, of small diameter, and therefore in itself 

 of no great consequence. The damage done, however, when the beetles 

 are numerous is economically very similar to that of the Xylchon. It has 

 already been noted that Xylcboriis perforam (p. 585) occasionally causes great 

 loss of beer from beer-casks in India, and since the Hill Breweries in 



