216 PROTECTION AGAINST INSECTS. 



ochreous. The head, side-margins and apex of the elytra 

 are blackish ; the latter do not quite cover the abdomen. 

 Larva white, with a fleshy hump on the last segment. 



(b) Lif e -history. ThQ beetle flies on warm days from the 

 beginning to the middle of July. The eggs are laid on large 

 broken tree- stumps, or on large barked oak logs, but never on 

 sound standing trees. The larvae eat galleries into the wood 

 of about 1 mm. in diameter and deflected at right angles 

 every few inches. The vertical burrows are somewhat 

 crooked, but the horizontal ones are quite straight. This 

 insect is chiefly injurious in timber depots and dockyards. 



In 1746, Linnaeus found the damage done to oak-timber in 

 the Gothenburg harbour so great that he exclaimed how 

 wonderful it was that so small a worm could do yearly so 

 many thousands of dollars' worth of injury. His advice to 

 the King of Sweden, at whose command he investigated the 

 injury, was to sink the affected timber under water before the 

 flight-time of the insects. 



Lymexylon is scarce and local in Great Britain, but is liable 

 to be imported in continental oak-timber. 



(c) Protective rules. Smearing felled timber with tar, when 

 attacks are feared. 



A similar species, Hylecoetus dermestoides, L., lives chiefly 

 in the stumps of felled trees ; it is locally common in Great 

 Britain, chiefly in Sherwood Forest, but has never proved so 

 destructive as Lymexylon to timber of commercial value. 



FAMILY V. ANOBIIDAE. 

 Description of Family. 



Imagos small, cylindrical, similar to bark-beetles, with a 

 cowled prothorax which conceals the upper part of the head. 

 Antennae slender, pectinate or clubbed, more rarely serrate, 

 8 to 11 -jointed, folded under the prothorax when the insect is 

 at rest. Fore and middle coxae cylindrical or spheroidal; 

 tarsi mostly 5-jointed, but 4-jointed in the case of many 

 species. Abdomen with 5 ventral segments. Generation 

 often lasting several years. The beetles when disturbed lie 

 motionless as if dead. 



