THE SOUTHERN PINE SAWYER. 



53 



transformations (figs. 19, c, 20). The unfinished arm of the "U" is 

 usually extended by the larva to within about one-quarter of an inch 

 of the surface of the wood. Wlien the lai"va pupates, the head of 

 the pupa is turned toward the end of the chamber. Wlien the pupa 

 changes to the atlult. the beetle extends the chamber to the surface of 

 the wood and through tlie bark, if the bark is still upon the tree or 







a 





.,MlU. :,!■ i 



Fig. ... , ..• I ,.,,., I .,,. showinp, al right, mass of (wrings and 



refuse packed under bark (bark removed) by the larvic and channels made 

 through the mass by the larvsr. a, Entrance hole of larva in wood; 6, scored sur- 

 face of wood; r.pgg pit; (/.emergence hole. .Vljout one-half natural size. (Original.) 



log, boring a perfectly round exit hole usually about three-eighths of 

 an inch in diameter (figs. 19, 21, 22), thereby escaping to propagate 

 the species in another tree or trees. 



NATURAL ENEMIES. 



Monohanmtus titillator is ])reye(l upon by larva' of the coleopterous 

 family Trogositithv; by the larva of an clateiid beetle of the genus 

 Alaus, and by a sjjccies of Bracon which has been iletermimHl as new 

 to science. None of these, however, has been powerful enough, so 



