384 The Ohio Naturalist. [Vol. XV, No. 2, 



Fig. 33. Celtis occidentalis affected by a gall-gnat, unde- 

 termined. 



Leaf gall, on under side, stoutly conical and nippled at tip. 

 Succulent, pale green, and covered with fine bloom when young. 

 3x4 mm. Present in great numbers. Larva white. 



Fig. 34. Celtis occidentalis affected by a gall-gnat, unde- 

 termined. 



Stoutly acorn-shaped gall, crowded along sides of green 

 twig and on either surface of leaf. Lower third ridged, whole 

 finely bristled, light green and 3-6 mm. diameter. Very abundant. 

 Larva light orange. 



Fig. 35. Celtis occidentalis affected by a gall-gnat, unde- 

 termined . 



Leaf gall, present in great numbers on underside. A "peg- 

 shaped" gall, cylindrical when young, and developing a thickened 

 base as it grows. Pale green, stragglingly hirsute, 2-3 mm. 

 long. Very common. Larva red. 



Fig. 36. Celtis occidentalis affected by the gall-gnat, 

 Cecidomyia unguicula Beutenm. 



Beutenmuller, Bull. Am. Mus. XXIII:388. 



Leaf gall of unmistakable "carpet-tack" fonn, usually found 

 on lower surface. Tip breaks off clean for emergence of insect. 

 Green to straw-color, 1..5-4 x 3-5 mm. Quite abundant, often in 

 company of one or more of the three preceding forms. 



Fig. 37. Celtis occidentalis affected by the psyllid Pachyp- 

 sylla celtidis-gemmae Riley. 



Riley, 5th Rep. U. S. Ent. Com. 618. 

 Beutenmuller, Bull. Am. Mus. IV, No. 1:275. 



Bud gall, being a rounded swelling and deformation of woody 

 consistency and about 5-10 mm. diameter. Rare. 



Fig. 38. Celtis occidentalis affected by the psyllid Pachyp- 

 sylla celtidis-mamma Riley. 



Riley, Johnson's Univ. Encyc. 1876. 

 Cook, Ins. Galls Ind. 844. 



Leaf gall, evident as a pit in upper surface, and as a sub- 

 spherical gall with constricted base on lower surface. Green- 

 glaucous, often brown-mottled. 3-5 x 4-6 mm. Abundant. 

 June-July. 



Fig. 39. Rosa sp. affected by the gall-wasp Rhodites rosaefoli^ 



Cockercll. 



Rhodites lenticularis Bassctt. 

 Cockerell, Ent. M. Mag. XXV:.324. 

 Beutenmuller, Bull. Am. Mus. XXI 1 1:646. 



Leaf gall, convex discoidal, projecting from both surfaces. 

 White and fairly hard. .5 x 4-5 mm. Common in July. 



