MONOGRAPH OF THE GENUS SAPERDA 27 



fed on the sap. When gnawing in the interior galleries they throw 

 the debris behind and void their excrement from time to time while 

 working; when tired or with hunger satisfied they take this frass 

 in their mandibles and pack it in the galleries and corners of the 

 " bark " chamber out of the way occasionally removing and repack- 

 ing in some other place. They will also carry it to openings in the 

 bark of their feeding chambers, and push it out, using the mandibles 

 only. When at work in the " bark " chamber they void their excre- 

 ment through one of the openings, ejecting it so that it will fall out- 

 side. This is usually done when the voided matter is soft and 

 watery. 



The life history of this insect may be summarized as follows : The 

 young borer, on the approach of winter, descends as near the ground 

 as its burrow will allow and remains inactive till the following spring, 

 when it begins operations anew, and on the approach of the second 

 winter it is about half grown and still living in the sapwood. It is 

 at this period that the most damage is done, for, where four or five 

 occur in a single tree, they almost girdle it. The next summer, when 

 it has become about three fourths grown, it cuts a cylindric passage 

 upward into the solid wood and, having finished its larval growth, 

 continues this passage to the bark, sometimes cutting entirely through 

 a tree to the opposite side and sometimes turning back at a different 

 angle. Several borers in one tree will fairly riddle its base [pi. 9]. 

 The upper end of the passage is stuffed with fine borings and the 

 lower part with long wood fibers [pi. i, fig. 5, 6]. After this the 

 larva remains unchanged through the winter, transforming to a pupa 

 the following spring, and the beetle appears some time during the 

 summer, leaving through a circular exit hole [pi. i, fig. 7; pi. 9]. 

 The latter frequently becomes overgrown, as represented in plate 8, 

 figure 4. 



Habitat. This species is said by Dr LeConte to occur in the 

 Middle, Western and Eastern states. Professor Cook states that it 

 is widely distributed in Michigan, and Rev. C. J. S. Bethune, writ- 

 ing of the insect in 1877, records it as very abundant in the Niagara 

 district and in the vicinity of Montreal and Quebec. Professor Mc- 

 Millan stated in 1888 that every orchard in Nebraska was infested. 



