Dec, 1914.] Insect Galls of Cedar Point. 38 1 



Fig. 19. Hicoria ovata affected by the gall-gnat Caryomyia 

 tubicola O. S. 



Cecidomyia tubicola Osten Sacken, Mon. Dipt. N. Am. pt. 1:192. 

 Felt, Journ. Ec. Ent. IV:456. 



Leaf-gall, on underside. Cylindrical, set in a socket from 

 which it readily detaches. 1.5x6 mm. Light green to red. 

 Fairly common. Huron, late July. 



Fig. 20. Quercus velutina affected by the gall-gnat Ceci- 

 domyia oruca Walsh (?) in company with an undetermined mite. 



Felt, Journ. Ec. Ent. IV:467. 



Leaf -gall, evident as a fold snug alongside veins on under 

 surface. Pouches isolated at times, but usually confluent and 

 present in great numbers. Brownish opening on upper surface, 

 resembling swollen lips of a knife-cut. In southern Ohio I have 

 seen every leaf on a good-sized tree dying from this gall, as early 

 as June. (The figure shows what are doubtless galls of Ceci- 

 domyia foliora Russ. & Hook., evident as infoldings of the edge.) 



Fig. 21. Quercus imbricaria affected by the gall-wasp 

 Andricus futilis 0. S. 



Cynips futilis Osten Sacken, Proc. Ent. Soc. Phi]. 1:63. 

 Andricus (Callirhytis) futilis Bassett. 

 Beutenmueller, Bull. Am. Mus. IV, No. 1:254. 



Leaf-gall, woody, flattened spherical, resembling a wart on the 

 upper surface and showing as a slight, nippled projection on 

 lower surface. Usually present in great numbers, on both Q. 

 imbricaria and Q. velutina. 2-4 mm. diameter, often confluent. 

 Dark brown. Quite common. July- August. 



Fig. 22. Quercus imbricaria affected by the gall-wasp 



Andricus singularis Bassett. 



Cytiips quercus-singidaris Bassett, Proc. Ent. Soc. Phil. 11:326. 



Cynips singularis O. S. 



Cook, Appendix Ins. Galls. Ind., p. 3. 



Leaf-gall, globular, about IS mm. diameter and showing 

 greater part of its bulk on under surface of leaf. Larval chamber, 

 2-3 mm. diameter, is supported in center by slender branching 

 filaments, radiating in all directions. Light brown and papery 

 when old. June 25. Fairly common. 



Fig. 23. Quercus alba affected by the gall-wasp Andricus 

 clavula Bassett. 



Cynips arbor Fitch. 



Cynips clavula Bassett, Proc. Ent. Soc. Phil. 111:686. 

 Andricus {Callirhvtis) clavula Bassett. 

 Beutenmiiller, Bull. Am. Mus. IV, No. 1:255. 



Twig-gall, being a club-shaped swelling of the extreme tip. 

 1.5 X 2-3 cm. Green, single-chambered, becoming woody and 

 dark after emergence of insect in midsummer. Surface often 

 corrugated and covered with cork spots. Cedar Point and 

 Huron. Common. 



