474 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



91. Dicerca prolongata Lee. Bores in the aspen (Cockerell, Ent. Mouth. 



Mag., London, March, 1888, p. 232; also for the specific characters 

 see Can. Ent., xx, p. 65). 



92. Xanthoma villosula (Mels.). Common on leaves. (Chittenden in 



letter). 



HEMIPTERA. 



93. Chaitopliorns candicans Koch. Balm of Gilead. 



94. Chaitophorus populicola Thos. 



95. Pemphigus populiramulorum Riley. 



96. Pemphigus populitransversus Riley. 



97. Pemphigus populimonilis Riley. 



98. Pemphigus pseudohyrsa (Walsh), 



99. Pemphigus vagabundus (Walsh). 



HYMEN OPTERA. 



100. Gimbex americana Leach. (Lugger, Bull. No. 9, Ag. Exp. Stat,, 

 Nov. 1889, p. 48). 



INSECTS INJURIOUS TO THE BASS-WOOD OR LINDEN TREE. 



Tilia americana Linn. 



AFFECTING THE TRUNK. 



1. The linden borer. 



Saperda vestita Say. 



Order Coleoptera ; family Cerambycid^. 



Boring in the trunk, undermining the bark for 6 or 8 inches in sinuous galleries, 

 or penetratiug the solid wood an equal distance, rather slender grubs, with three 

 pairs of thoracic feet, transforming into a greenish snuff-yellow longicorn beetle, with 

 six black spots near the middle of the back. 



''~"\ / 



Fig. 171.— The Linden borer, beetle of nat. size, a, upper, 6, under, side of head and three thoracic 

 segments ; c, side view of head of grab ; d, top view of two segments, showing theoval spots ; e, the 

 grub, slightly enlarged. — From Packard. 



The beetles, according to Dr. Paul Swift, as quoted by Dr. Harris, 

 were found in Philadelphia upon the small branches and leaves May 

 28, and it is said that they come out as early as the first of the month, 



