INSECTS AFFECTING PARK AND WOODLAND TREES 



465 



Xyphidria provancheri Cress. 



The larvae of a sawfly may be found boring in the partly decayed wood of standing 

 white birch trees, making a gallery about >8 inch in diameter, the adults emerge from 

 the tree through circular holes of about the same size. 



This species was met with Aug. 20, 1900, at Saranac Inn, where the 

 larvae were working in a partly rotten standing birch, and living adults bred 

 therefrom Sep. 6, 1901. A few of the insects had emerged earlier and then 

 died. 



Description. The adult sawtly is a jet-black insect, about 54; inch long, 

 with a yellowish white mark on the dorsum and one on the posterior lateral 

 corner of the head, ont' at the Ixise of the 

 wings, one each on the sides of the third 

 to the si.xth and the eighth abdominal seg- 

 ments. Those on the head and at the 

 base of the wings are .somewhat elongate, 

 broken and angulated in the latter, while 

 those on segments 3 to 6 of the abdomen 

 are subtriangular, and that on the eighth 

 segment is subquadrangidar. I he man- 

 dibles are a deep rufous, tipped with black, 

 and the mouth is bordered anteriorly and 

 laterally with yellowish white. The dor- 

 sum of the head and the thora.x is rough, 

 tuberculate. The wing spread is about 

 one inch. The male is more slendei^ and 

 a little smaller than the female. 



The larva when taken in August was 

 about 5/8 inch long, of a yellowish wdiite 

 color. The head is* a creamy white, with the mouth parts bordered with 

 black. The segmentation is well indicated and the thoracic segments 

 bear somewhat rudimentary legs. The posterior extremity of the body 

 is tipped with a short dark brown spine which rises from a yellowish brown 



FiK. 115 Xyitltidria ii ro va n cb e ri, work in 

 liirch, sliowitij; jmiji-iI rells .tiid exit hrilc-; (original) 



