INSECTS OF THE PRICKLY ASH. 659 



Scale of the female. — The scale of the female la snowy white, with the exuviae yel- 

 lowish. It is flat, quite delicate in texture, and varies greatly in shape ; it wideus 

 suddenly near the posterior end of the second skin, often becoming as wide as long ; 

 some specimens are straight, others are bent to the right or left. Length, L5™°> 

 (.05 inch). 



INSECTS INJURIOUS TO THE PRICKLY ASH. 



Zanthoxylum americanum. 



AFFECTINGr THE TRUNKS AND LIMBS. 



1. The Prickly Ash Borer. 



Liopua xanthoxyli Shimer. 



Order Coleoptera; family Cerambycid^. 



This borer was discovered May 25, in Illinois, by Dr. Shimer, in trunks 

 of the prickly ash, which had been barked during the previous July. 

 In the burrows were several pink-orange pupje, invariably lying with 

 their heads outward ; from these he bred an undescribed species related 

 to L. alpha. The beetle appeared on the tree about the middle of June. 

 He sent one specimen from which the following descriptions have been 

 drawn up : 



Larva.— {For figs, see ray first Rep. Inj. Ins. Mass.) Is very much like that of Zio- 

 pu8 faceius. The head is a little more than half as wide as the prothoracic ring. 

 The basal (occipito-epicranial) region is transversely oblong, the basal piece (occi- 

 put) being very short, and transversely almost linear, and separated by a well-marked 



Fig. 215. — 1. Liopus xanthoxyli. Fig. 216. — 2. Liopusfacettig. 



suture from the middle portion (epicranium) ot the head, the latter being nearly 

 four times as broad as long, with the front edge straight ; it is white, with the front 

 edge pitchy black. The clypeus is smooth, trapezoidal in form, and three times as 

 wide as long. The upper lip (labrum) is thin, hairy, transversely elliptical, a little 

 less than one-half as long as broad. The basal chin piece (submentum) is a large 

 transversely oblong area, with the front edge piceous, and very slightly hollowed, 

 while the posterior edge is very deeply hollowed out. The chin (mentum) is nearly 

 square, widening at the base, which is continuous with the base of the maxillae, the 

 whole posterior edge being well rounded. The labial palpi are three-jointed, the 

 basal joints of each palpus being large, and no longer than broad, and touching each 

 other; the second joint is much slenderer, and about half as thick as the basal joint; 



