NEW YORK STATE MUSEUM 89 



exit hole is broadly oval with dimensions about three-eighths by 

 five-eighths of an inch. This leads into a gallery which penetrates 

 the wood perpendicularly for a distance of 2 or 3 inches. Packard 

 states that the eggs are deposited the latter part of June, in the 

 bark, the young grubs running galleries mostly lengthwise and well 

 filled with borings. 



Pigeon tremex (Tremex columba Linn.) . The grubs 

 of this large horn tail or four-winged fly are very common in 

 diseased or dying portions of the larger limbs and trunks of vari- 

 ous trees, particularly elms and maples. The parent insect has a 

 length of about 2 inches, a wing-spread of 2^4 inches, a prominent 

 horn at the posterior extremity and may be recognized by its cylin- 

 drical dark-brown abdomen with its yellowish markings. Not infre- 

 quently these flies are found upon affected trees and are occasionally 

 trapped and perish through inability to withdraw the needlelike 

 ovipositor from the wood. 



This insect was reared in small numbers the following mid- 

 summer from a hickory log cut in February 191 5, and an exami- 

 nation the following February resulted in finding fully formed 

 living adults which would suggest a two-year life cycle, since con- 

 ditions were such that the initial infestation might well have 

 occurred in 1914. The probabilities were certainly against these 

 Tremex adults having developed from eggs deposited the preceding 

 summer. 



Hickory timber beetle (Xyleborus celsus Eich.) . This 

 is one of the longer of our ambrosia beetles, it being about three- 

 sixteenths of an inch long, cylindrical and brownish. It makes 

 a series of galleries of nearly uniform diameter in hickory and 

 oak. The entrance holes usually lead to a perpendicular gallery 1 

 or 2 inches long from which there are branches at irregular inter- 

 vals and sometimes with a decidedly sinuous course. They cut the 

 wood at right angles to the grain and lie in nearly the same hori- 

 zontal plane, occasionally penetrating the trunk to a depth of 7 

 inches. This insect, like its allies is of unusual interest because it 

 lives upon a peculiar fungus or ambrosia which develops in the 

 galleries. 



A considerable number of these timber beetles were reared in 

 late March from a hickory log cut the preceding February and a 

 careful examination later in the season showed practically nothing 

 alive. The insects had presumably ceased breeding and deserted 

 the log because of unfavorable conditions. 



Monophylla terminatus Say. This insect is a small, cylindrical, 



