NATUEAL ENEllIES OF THE FOREST. 



243 



Fig-. 92. Work of Ambrosia Beetle, 

 Xyloborus celsiis, in Hickory Wood: a, 

 Iv'arva: l\ Pupa; f, Adult beetle; (/, Char- 

 acter of work in' lumber cut from in- 

 jured log-; e. Bark;/, Sap-wood; g. Heart- 

 wood. \Agric. JVar 7j'(io<-, 1<)04, Fig. -H, 

 p. 384.1 



Thei-e are t\vo general types or classes of 

 these galleries, one in which the broods de- 

 velop together in the main burrows, tlie other, 

 in whieli the individuals develop in short 

 separate side cliambers extending at right 

 angles from the primary gallery. Fig. 93. 

 'i'lie galleries of the latter type are usually 

 accompanied by a distinct staining of the 

 wood, while those of the former are not. 

 (Hopkins, A(jric. Yr. Bk., 1904, p. 38.3.) 



Bark and loood borers, Fig. 94. This 



class of enemies differs from the preceding in the fact that the parent beetles 



do not burrow into the wood or bark, but deposit their eggs on the surface. 



The elongate, whitish, round-headed {Ceramhijcid) , flat-headed (Buprestid), 



or short, stout (Cuixalionid) 



grubs hatching from these 



Fig. 91. Brood Galleries of 

 the Oak Bark Beetle, showing 

 Character of Primary Gallery 

 at />; Larval or Brood Mines a"t 

 a. I Agric. J 'car Boo/c, 1903, Fig. 

 30, page 31S.I 



eggs cause injury by bur- 

 rowing beneath the bark, or 

 deep into the sap-wood ;rnd 

 heart-wood of living, in- 

 jured and dead trees. saw- 

 Jogs, etc. Some of the spe- 

 cies infest living trees. Fig. 

 95, causing serious injury 

 or death. Others attack 

 only dead or dying bark and 

 -wood, but this injury often 

 results in great loss from 

 the so-called wormhole de- 

 fects. (A. D. Hopkins, 

 Bntom. Bun.. No 48, p. 10.) 



Fig. 93. Wcrk of Ambrosia Beetles in 

 Oak; ti, MonartltiiDi mali, and work; 

 /', Platypus compositn.s^ and work; c. 

 Bark; V, Sap-wood; f. Heart-wood; /", 

 character of work in lumber from in- 

 jured log. [Asrk. JcoriJoo,!-, 1904, Fig. 

 45, p. 384.] 



