Injurious and Beneficial Insects. 



15 



plish tinge. The head and prothorax are blackish except on 

 the hinder edge of the prothorax. Tlie antennse are yellowish 

 brown, with the basal joint and articulations between the other 

 joints dark brown. The wing covers are pale ash, with a pur- 

 plish tinge, and an irregular rounded spot just behind the scutel- 

 lum, united when the wings are folded with a similar spot on 

 the other wing cover. The shoulder of each wing-cover is 

 tipped with black, which extends backwards from a longitudinal 

 large black spot extending backwards and connecting with a 

 broad black band which crosses the terminal third of the wing, 

 leaving the tip pale gray. The front edge of this band forms 

 an acute angle in the middle of the wing ; this band is some- 

 times partially wanting, and is then broken up posteriorly into 

 a few black spots. In front of this broad band is an oblique 

 row of short (longitudinal) lines, the first and innermost being 

 shortest ; the second one nearly three times as long and parallel 

 to the costal spot. It is a little less than a quarter of an inch 

 (.20) in length. 



T/ie Prickly Ash Borer (^Leiopiis xanthoxyli Shinier, Plate 1, 

 Fig. 2). In this connection descriptions of the ditferent stages 

 of this species, which has only yet been found in Illinois by Dr. 

 Sliimer, to whom I am indebted for specimens, would seem 

 necessary, inasmuch as they throw light on the structure of the 

 apple Leiopus. According to Dr. Shimer it bores into the limbs 

 of the prickly ash. 



The larva (Fig. 7, a, larva ; b, upper side ; c, under side of 

 the head) is very much like 

 tliat of the preceding spe- 

 cies. The head is a little 

 more than half as wide as 

 the prothoracic ring. The 

 basal (occipito - epicranial) 

 region is transversely ob- 

 long, the basal piece (occi- 

 put) being very sliort, and 

 transversely almost linear, 

 and separated by a well-marked suture from the middle portion 

 (epicranium) of the head, the latter being nearly four times as 

 l)road as long, with the front edge straight ; it is white, with the 

 iront edge pitchy black. The clypeus is smooth, trapezoidid in 



