ON SOME OF THE NORTH AMERICAN COSSID^, WITH FACTS IN 

 THE LIFE HISTORY OF COSSUS CENTERENSIS Lintner. 



By James S. Bailey, A. M., M. I).. Albany. X. Y. 



Cossus centerensis (Plate I) was discovered by Dr. Theodore P. Bailey 

 in 1877. For many years previous I had observed that many trees of the 

 r<>pulu.s tremuloides had perished from some cause then uuknown. The 

 central shoots of other trees of the same species were dead, and it would 

 only require a few years to finish their destruction. Perforations were 

 found in the trunks of these trees, some of recent date and some over- 

 grown with bark, leaving the cicatrices plainly visible. 



In July, 1S7G, a brittle pupa-case of the Cossus was found projecting 

 from one of the openings, which gave the first clue to the nature of the 

 borer and destroyer of the timber. 



On the 10th of June. 1877. a fresh pupa-case was discovered, and on 

 the 14th of the same month the first Cossus was captured, resting upon 

 the same tree trunk. Every season since this capture the Cossus has 

 been taken, but in some years in greater numbers than others. 



The Cossus usually comes forth between the setting and rising of the 

 sun, and when the trees are visited daily the protruding pupa-cases left 

 behind by the escaped imagines informs the collector how many of the 

 nsecta he may expect to And. 



Their color similates so closely the color of the bark of the trees that 

 it requires good eyes and very close observation to find the moth*. 

 One unaccustomed to collect them might view an infested tree for a 

 long time and not find a Cossus, when several would be discovered by 

 an expert. An uneven protuberance on the bark, or the short stump 

 left of a decayed broken limb are favorite resting places for the in- 



The moth at first is rather sluggish, and can be easily captured. After 

 it has been abroad for some days it is wild and more or less muti- 

 lated. This Cossus is not attracted by sugar, as might be expected 

 from its aborted tongue.* The moth seems to belong to the genus (Jos 1 

 sm Fabr., and not to be congeneric with Xystus robinice. The bead is 

 short, eyes naked, labial palpi small, appressed, scaled. The thorax is 

 thickly scaled, the scales gathered into a ridge behind, and is s.piarer 



" The writer is desirous of producing ;ill the known farts in reference to this insect 

 in tirs paper; therefore the descriptive parts which have been published before arc 

 reproduced. 



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