IXSECTS AFFECTIXr, I'ARf. WD WOODI-ANT) TRFES -5^,5 



fusor Kirln. The parent of this latter insect is rcprcsentttd at plate 63, 

 figure 1, and its operations are familiar to many lumhermeii because' its 

 coarse while sawdusllike chips may be fre(iuentl\- observed drop|)in_<4- from 

 logs piled in mill yards and its large galleries are not uncommon defects in 

 timber. The sau\er is rarely f(nuid attacking li\ing trees. It prefers to 

 breed in those which are ilying or nearl\- dead and therefore is a follower of 

 the above noted barkborers. Other s|)ecies have; a similar habit, notably 

 tlie rii)bed rhaginm, R h a g i 11 m 1 i n e a t u m ( )li\-., a species which is fre- 

 quently destructive to the bark of trees previous])- killed b\- other insects. 

 Its JM-oad tlattened grub cU-lights to revel in moist decaying tissues and 

 its ver)- charactt'ristic cells | pi. 64, fig. 7, S, io| are walled liy long white 

 splinters torn from the wood forming a portion of its oval pupal cell. 

 Another s|)ecies, I'yiho americanus Kirb\-, is also associated with 

 the preceding in this work of reducing decaying tissues to a still finer 

 condition. It ma\- be easily recognized l)y its oval cells which insteatl 

 of being liordered by linear chij^s torn from the surface of tlu! wood are 

 lined with nearly deca\ed debris from the bark \ sir pi. 64, fig. 6, 9]. 



These two species in conjunctioji with the i)ark borers soon reduce the 

 inner tissues of an attacked tree to a mass of d(;cayed vegetable matter and 

 render the stripping of the itark an easy matter. Plate 56, figure 2, illus- 

 trates the secrec\- of these operations very nicel\-. Apparently the trunk of 

 the tree has suffered little or no injur\-, but on removing the bark its inner 

 layers are found to be a mass of corruption, as shown at plate 56, figure t,. 

 The bark loosens and soon drops in large patches, e.xposing the wood to 

 other enemies such as ambrosia beetles. 



The condition of such a tree which scarcely two years before it w^as 

 photographed was in full vigor, is well shown at plate 54, figure i. The 

 small Ijlack holes in the bare wood are entrances to galleries of wood l)orers 

 known as ambrosia beetles and these lead into lateral galleries from which 

 in turn there are series of perpendicular chambers. This latter insect, 

 X\ lo terns bivittatus Kirbv, is common in soft woods and is 



