NOTES ON THE LIFE HISTORY AND EARLY STAGES OF 

 CORYTHUCHA CELTIDIS O. & D. 



Harry B. Weiss, 

 New Brunswick, N. J. 



This lace-bug was described by Osborn & Drake in 1916 in 

 the Ohio State University Bulletin (Vol. XX, No. 35, Bulletin 

 8, Vol. II, No. 4, p. 227) from specimens taken at Columbus, 

 Ohio, during September, 1903, on hackberry. Later these same 

 authors in the Ohio Journal of Science (Vol. XIX, No. 7, 

 May, 1919) recorded its occurrence in Kentucky, Tennessee and 

 South Carolina. Gibson also treats this species in his paper on 

 the genus Corythucha which appeared in 1918 (Tr. Am. Ent. 

 Soc. XLIV, 69-104). Heretofore nothing has appeared on its 

 life history and early stages and the following is presented as an 

 addition to the knowledge of the biology of this species. 



Adults were first noted in New Jersey at Riverton on June 1, 

 depositing eggs on the lower surfaces of hackberry leaves. 

 Later, on June 21, adults and eggs were collected at New 

 Brunswick, N. J., and from this it appears that the insect is well 

 distributed in this state. About two weeks are necessary for the 

 eggs to hatch and the various stages each require from 2 to 4 

 days of very warm weather in which to complete their growth. 

 Cool weather retards development. There are 5 nymphal 

 stages and from 16 to 20 days are necessary for a newly hatched 

 nymph to become an adult. Two generations occur in the lat- 

 itude of New Brunswick, N.J. Newly hatched nymphs feed in 

 colonies on the lower leaf surface but as they become older they 

 scatter and feed more or less independently. Many colonies 

 of nymphs are wiped out completely by spiders and predaceous 

 bugs and their nymphs. 



The eggs are inserted in the tissue of the lower leaf surface 

 at right angles to the leaf, usually in the angle formed by the 

 juncture of two veins. Only the basal end of the egg is inserted 

 and each egg protrudes well beyond the leaf surface. They are 

 laid close to one another and the clusters may contain anywhere 

 from 4 to 18 eggs. The adults appear to wander over the tree 

 considerably in the spring and as a result the egg clusters are 

 scattered. Only rarely was it possible to find more than one or 



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