72 



Leperisinus cinereus Sw.; Dom. Ent. Br., Dept. Agric, Bull,, 14: 15, 1917. 



Easily separated by the characters given in the key. Apparently a 

 rare species. 



Host trees. — Ash. 



Distribution. — Hudson and Ste. Anne de Bellevue, Que.; Cambridge, 

 Roxbury, and Brooklin, Mass. 



Leperisinus pruinosus Eichh.; Berl. Ent. Zeit., 149, 1868. 



The species accepted here as pruinosus Eichh., heretofore confused 

 with aculeatus Say, agrees well with Eichhoff's description. 



Distribution.- — Represented in our collection from Michigan, Pennsyl- 

 vania, and Tennessee. 



Leperisinus aculeatus Say; Acad. Nat. Sci. Phil. Jour., 3: 322, 1826; ed. Lee, 

 2: 181. 



Length, 2 • 3 mm. to 3 mm. ; the colour-markings usually distinct, formed 

 of greyish and dark scales in alternate subregular bands; on the pronotum 

 the scales greyish except on a diamond-shaped median area and an elongate 

 lateral area; on the elytra the pale markings in three subtransverse bands 

 across the disc and a wide band along each side, the 1st band transverse, 

 sub-basal, the 2nd and 3rd oblique on each elytron, forming two-angled 

 bands, angled behind; the intervening dark areas with scales coloured like 

 the background. The male has the front more distinctly flattened and 

 more densely hairy than the female. 



Host tree. — Ash. 



Distribution. — Eastern Canada, following the distribution of its host 

 tree from Manitoba to the Maritime Provinces; Eastern United States, 

 represented in our collection from Michigan and Kansas eastward through 

 New York state and Massachusetts. 



The brood tunnels are very abundant in dying and recently killed 

 trunks and limbs; short hibernating tunnels are cut in the middle bark 

 of living trunks; a secondary enemy; often nearly exterminated in a limited 

 locality by hymenopterous parasites and mites. 



Leperisinus criddlei n. sp. 



Length, 2 mm. to 2-6 mm.; of smaller average size than aculeatus Say, 

 with distinct colour-markings and characters as given in the key. 



Type; Aweme, Manitoba; 21-VII-1915; 8178; N. Criddle, Type No. 

 102. 



Host trees. — Green Ash, White Ash. 



Distribution. — Aweme, Man.; St. Hilaire, Que. 



PLATE 16. 

 IPID STRUCTURES— All Much Enlarged. (Original.) A.E.K. 



Fig. 1, Dryocoetes confusus Sw., head from the side, female. 



Fig. 2, Ips tridens Mannh., head from the side, female. 



Fig. 3, Pityokteines sparsus Lee, head from the side, and pronotum from above, female. 



Fig. 4, Pityophthorus nudus Sw., elytral decHvity. 



Fig. 5, Dryocoetes affaber Mannh., head from the side. 



Fig. 6, Pityophthorus canadensis Sw., head from the front; male and female. 



Fig. 7, Pityophthorus pulicarius Zimm., elytral decHvity. 



Fig. 8, Pityophthorus canadensis Sw., elytral dechvity, female. 



