88 INSECTS INJURIOUS TO VEGETATION. 



burrows are wide and not cylindrical, are very winding, and 

 are filled up with a kind of compact sawdust as fast as the 

 insects advance. The larva state is said to continue two years, 

 during which period the insects cast their skins several times. 

 The sides of the body in the pupa are thin-edged, and finely 

 notched, and the tail is forked. 



One of the most common kinds of CaUidium found here is 

 a flatfish, rusty black beetle, with some downy whitish spots 

 across the middle of the wing-covers ; the thorax is nearly cir- 

 cular, is covered with fine whitish down, and has two elevated 

 polished black points upon it; and the wing covers are very 

 coarsely punctured. It measiu-es from four tenths to three 

 quarters of an inch in length. This insect is the CaUidium 

 bajulus ; the second name, meaning a porter, was given to it 

 by Linnseus on account of the whitish patch which it bears on 

 its back. It inhabits fir, spruce, and hemlock wood and lum- 

 ber, and may often be seen on wooden buildings and fences in 

 July and August. We are informed by Kirby and Spence 

 that the grubs sometimes greatly injure the wood-work of 

 houses in London, piercing the rafters of the roofs in every 

 direction, and, when arrived at maturity, even penetrating 

 through sheets of lead which covered the place of their exit. 

 One piece of lead, only eight inches long and four broad, con- 

 tained twelve oval holes made by these insects, and fragments 

 of the lead were found in their stomachs. As this insect is 

 now common in the maritime parts of the United States, it 

 was probably first brought to this country by vessels from 

 Europe. 



The violet CaUidium, CaUidium violacetim* is of a Prussian 

 blue or violet color ; the thorax is transversely oval, and downy, 

 and sometimes has a greenish tinge ; and the wing-covers are 

 rough with thick irregular punctures. Its length varies from 

 four to six tenths of an inch. It may be found in great 

 abundance on piles of pine wood, from the middle of May to 

 the first of June ; and the larvae and pupae are often met with 

 in splitting the wood. They live mostly just under the bark, 



* Cerambyx violaceus of Linnseus. 



