66 NEW YORK STATE MUSEUM 



points not present on the anterior row; posterior extremity slightly 

 infuscated and with a series of irregular, tuber culate processes, 

 modifications of the spines noted on the preceding segments. 



The parent fly is a dark brown or blackish gnat or midge about 

 one-tenth of an inch long and most easily recognized by the mod- 

 erately short, black antennae and the long stem of the Sciara-like 

 fork of the greatly reduced median wing vein. The venation is 

 so peculiar as to admit of a ready identification of the species. 



Attack by this species is probably favored by a slight wound or 

 scar or even a small cavity following the healing over of a place 

 where a limb has been removed and the presence of more or less 

 dead organic matter, the latter keeping the deeper portion of the 

 wound moist and presumably offering favorable conditions for the 

 deposition of eggs and the development of the small maggots which, 

 as they increase in size, attack adjacent tissues and soon produce 

 the characteristic bleeding. The frequent precipitation in the early 

 part of last season was favorable for the development of this insect 

 and appears to have been accompanied by an unusual amount of 

 injury. The recurrence of this trouble from season to season in 

 no way invalidates the above, since with the approach of cold weather 

 these insects would naturally suspend operations and there would 

 be no breeding until the following spring. The discoloration of 

 the bark and the sour odor may be easily explained by the precip- 

 itates, due to evaporation and fermentation caused by various 

 organisms which establish themselves in collections of moisture con- 

 taining various elements of food. 



The most promising treatment for this type of injury is simply 

 to remove the dead tissues, cut down to the healthy wood and pro- 

 vide adequate drainage for the cavity, if one of any size exists. The 

 wound should then be dressed with some protective material, such 

 as grafting wax, tar or paint. 



Pigeon Tremex (Tremex columba Linn.) . This species 

 was reared in small numbers in midsummer, 191 5, from a hickory log 

 cut the previous February, and in the winter of 19 16 fully devel- 

 oped living adults were found. These latter suggest a two-year 

 life cycle for this species, since conditions were such that the initial 

 infestation might well have occurred in 19 13. The probabilities were 

 decidedly against the Tremex larvae alive in the log in the winter, of 

 19 16 having developed from eggs deposited the preceding summer. 



The larvae of the pigeon Tremex are rather common in dead, 

 particularly fungous-affected wood of various trees, and on account 

 of this insect restricting itself to dead or dying tissues, it can not be 

 considered of much economic importance. 



