THE ELM-BARK BEETLE 49 



within the bark, to the weather or to the attacks of insect- 

 eating birds ; the wintering larvas avoid this danger by boring 

 into the wood and resting there. Beetles which complete 

 their transformation in August run less risk, and do not need 

 to excavate beneath the bark. 



There is reason to believe that the bark-beetles often begin 

 their attack on the topmost boughs of an elm, which become 

 dry and brittle in consequence, and gradually work their way 

 down to the main trunk.* 



The larva of the elm-bark beetle is a whitish, soft, and 

 footless grub, much resembling weevil-larva; in general appear- 

 ance. _ It is thicker in front, and tapers behind. The back 

 and sides are marked by 

 deep wrinkles. The head 

 is hard, and armed with 

 powerful jaws. The pupa is 

 very similar to that of many 

 other beetles, and no re- 

 markable details have been 

 recorded concerning it. The 

 perfect insect is 4-5 mm. 

 long, black, with obscure 

 markings of red or brown p; 



on the elytra and legs. The Elm-bai-k beetle, x lo. After RUzema Bos. 



feelers are rather short, bent, 



and clubbed. The rostrum, which carries the mouth-parts, and 

 which is long and slender in many weevils, is here very short. 

 The thorax is enormous in proportion to the abdomen, and ex- 

 tends so far back on the under side of the body that the hind 

 legs are attached beneath the middle of the elytra. The tarsi, 

 until minutely examined, appear to be four-jointed. The under 

 surface of the particularly short abdomen slants upwards towards 

 the end of the body, and looks as if a great piece had been cut 

 away by an oblique incision. The elytra are marked by 6-7 

 longitudinal streaks, which are resolved by a lens into rows of dots. 

 The bent and clubbed feelers, the apparently 4-jointed tarsus, 

 the striate elytra, and the footless larva indicate that the elm- 

 bark beetle is allied to the weevils, though the rostrum, which is 

 greatly prolonged in most weevils, is here short and inconspicuous. 



* Oberforster Brecher, in Altum's " Forstzoologie," III., Insect en, 

 Abth. i. p. 244 (2nd ed. 1881). 



