50 



SOME INSECTS INJURIOUS TO FORESTS. 



to the adult. In the case of the sawyer, however, the winter is 

 passed in the larval stage and not the pupal stage. In November, 

 1908, Mr. K. W. Van Horn found emergence holes of the sawyer 

 in trees felled the previous spring near Virginia Beach, Va., thus 

 showing that the same conditions prevail there. 



Among the larvae which pass the winter in the logs, those which 

 are farthest advanced in development are, of course, the first to go 

 through the changes to the adult, and to emerge in the spring. It 

 is probable that this emergence begins about March 1. At the time 

 the writer was in southern Mississippi, March 18-20, 1909, many 

 adults had already emerged and others were ready to emerge. Fe- 

 males were actively engaged in laying eggs at this time. 



Just how long it takes for all the overwintered larvse, which 

 have not already done so, to go through the changes to the adult 

 stage and emerge is not known, but it is probable that this will be 

 accomplished at least by June 1. 



From the last of July, 1908, to the first of February, 1909, the 

 writer had' trap trees felled at stated intervals, for the purpose of 

 getting seasonal history notes. The following tabulation shows the 

 net results of these experiments : 



Seasonal history records of the pine sawyer from pine trees felled from July, 1908, ii 



February, 1909. 



Hopk. 



U.S. 



No. 



5873 

 5874 

 5879 

 5880 

 •5885 

 5886 

 5893 

 5894 



5895 



6897 



5898 

 5914 



5915 



5913 

 6910 



6911 



5908 

 6909 



6906 



5907 



Condition on March 18-19, 1909. 



LarvsB and pupse in wood. A good many adults have emerged. 



LarvsB, pupse, and young adults in wood. A good many adults have emerged. 



LarvEe and pupse in wood. No emergence holes noted. 



Do. 

 Larvae and pupae plentiful in wood. No emergence holes noted. 

 Larvae and pupse common in wood. Three adults have emerged. 

 Larvae and pupae in wood. Several adults have emerged. 

 Larvae and pupae in wood very scarce. One young adult (quite small). Two 



adults have emerged. 

 Larvae and pupae in wood. No emergence holes. 

 Larvae and pupae rather scarce in wood. A few adults have emerged. A few 



larvae between bark and wood, scoring the wood. 

 LarviB and pupae in wood. One larva found between bark and wood, which 



crawled back into its hole in the wood. One adult has emerged. 

 Lairvae, pupae, and young adults In wood. Several adults have emerged. 

 Larvae, some of which have not entered wood, others in wood with exit burrow 



excavated nearly to surface. No pupae or emergence holes. 

 Larvae, some between bark and wood, scoring the wood, not having made 



entrance holes Into wood. Others in wood with emergence gallery excavated 



nearly to surface. No pupae or emergence holes noted. 

 A few inconspicuous egg pits evidently made last tall. Two half-grown larvae, 



one of which had commenced to mine into the wood. The other had not 



commenced to do so. 

 Two or three egg pits, evidently made last fall, but no larvae or eggs found. 

 Many egg pits. ]i,ggs and young larvae in some ca^es, in others the conditions 



seem to nave become unfit by reason of the excavations of other insects. 

 Many egg pits. Eggs and young larvae under bark. 



A few egg pits of Monohammus with eggs. One small larva found. 

 Scattormg egg pits over the log. Eggs and larvae apparently one or two weeks 



old. 

 A few egg pits, both in trunk and stump. Eggs under bark, but none found 



that have hatched. March 20, female digging egg pit. 

 A few egg pits with eggs under the bark. One larva found apparently just 



hatching. March 20, six beetles, three males and three females, observed 



on this log, the females excavating egg pits, two males fighting and the other 



male hanging on to a female. 



