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Notes on Hylesinus aculeatus and Phloeosinus dentatus. 



]>v Wakrex Knaus. Salina, Kansas. 



The Scolytidce are but sparsely represented in the coleopterous fauna 

 of Kansas. This scarcity is accounted for in great part by the absence 

 of forests over the greater part of the State; the natural home of these 

 Coleoptera being beneath the bark of shrubs and trees, where a large 

 part of the imaginal, and the whole of the larval life is passed. 



Of the seven or eight species of this family in this State, as given m 

 the various Reports of the Kansas Academy of Science, but three have 

 come under my personal observation, and but one {P. dentatus) has 

 actually been observed at work. 



The burrows of a Scolytid in an ash post, which I supposed was the 

 work of the ' 'Ash Bark Borer", came under my observation about one 

 year ago. The work however, was not recent and no specimens were 

 obtained. Specimens of the sculpture were retained, but efforts to find 

 more recent work were not successful until about the middle of July, 

 1885, when I secured well preserved specimens, though dead, of an in- 

 sect, from ash posts, near Stockton, Rooks County, and Edmond, 

 Norten County. These specimens proved on identification to be 

 Hylesinus aculeatus Say. No growing trees were found which had been 

 attacked, and those only were selected that were already in a decaying 

 condition. 



The burrows of this insect were almost facsimiles in every particular, 

 consisting of a larger central channel from 25 to 100 mm. in length and 

 I mm. in width, made by the female, the young larvae eating its way 

 outward fron\ this channel, the larval channels constantly enlarging 

 during the larval life, and sinking a little deeper in the wood as the 

 pupa state is reached. These larval channels are from 5 to 45 mm. in 

 length and from \ to 1 mm. in width. The central channel is usually 

 slightly sinuous, being governed to some extent by the surface of the 

 wood and the number of beetles at work, they never coming in contact. 

 At about midway of the central channel there is in every instance a 

 change of direction, — a curve, sometimes hardly perceptible, at other 

 times and usually, very marked. The lateral larval channels extend 

 outward at right angles from the central channel, and are about one third 

 the length of the former, that varying from one to three inches in length. 



In November 1885, live specimens of this insect were taken from 

 ash trees in the western part of Davis County. The bark of these trees 

 had apparently been abraded about a month previous, and had been at 

 once attacked by Hylesinus aculeains. Large numbers of these had 



