Dec, 1914.] Insect Galls of Cedar Point. 379 



Fig. 8. Populus deltoides affected by the louse Pemphigus 

 popuUcauUs Fitch. 



Bvrsocrvpta populicaulis Walsh. 

 Fitch, Rep. N. Y. Ent. V:845. 

 Cook, Ins. Galls Ind.:849. 



Dome-shaped gall at junction of leaf and petiole, the opening 

 at base of dome being a spiral slit caused by the complete curving 

 of the petiole on itself. 5-10 x 10-15 mm. Color normal, with 

 gray flecks of cork. Very common. July. 



Fig. 9. Populus deltoides affected by the louse Pemphigus 

 populitransversus Riley, Bull. U. S. Geol. Surv. V:15. 



Cook, Ins. Galls Ind.:850. 



Petiole gall, being a spherical, subspherical, or spindle-shaped 

 enlargement, rarely involving base of leaf, and developing a 

 small transverse median slit for emergence of the lice. 8-12 mm. 

 diameter, color being that of normal petiole. July. Very 

 common. 



Fig. 10. Populus deltoides affected by the louse Pemphigus 

 vagabundus Walsh. 



Byrsocrypta vagabunda Walsh. Proc. Ent. Soc. Phil. 1:306. 

 Cook, Ins. Galls Ind.:850. 



Terminal bud-gall of leathery texture, flatly saccate, but very 

 irregularly lobed and branched, developing labiate openings at 

 peripheral points for emergence of parasites. Size varies greatly 

 up to 1 dm. in diameter. Color light yellow-green, with tinges of 

 red, rapidly discoloring on maturity. July 1. Very common. 



Fig. 11. Betula sp. affected by the mite Eriophyes brevi- 

 tarsus Focksu (?), Rev. Biol. Nord. France 111:3. 

 Banks, Cat. N. A. Acarinae. 



Tiny pouch-gall, irregularly scattered over leaf, and opening 

 on under surface. .5-1. mm. diameter. Green, rapidly dis- 

 coloring. 



Fig. 12. Betula sp. affected by the louse Hamamelistes 



spinosus Shimer. 



Hormaphis papyraceae Oestlund. 

 Shimer, Trans. Am. Soc. 1:284. 

 Patch, Bull. 220, Me. Ag. Exp. Sta.:279. 



Leaf-gall, being a fold along the lateral veins, opening on 

 under side of leaf, which is often seriously deformed by the presence 

 of one or more such galls. Fold filled with white flocculent 

 excreta. This louse is found on the witch hazel an alternate host, 

 hence the generic name of the insect. 



