Dec., 1914.] 
Insect Galls of Cedar Point. 
379 
Fig. 8. Populus deltoides affected by the louse Pemphigus 
populicaulis Fitch. 
Byrsocrypta 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 III: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. J: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. 
