December, '19] wellhousE: hawthorn lace bug 441 



LACE BUG ON HAWTHORN, CORYTHUCHA BELLULA GIBSON^ 



(TINGIDID^, HEMIPTERA) 



By Walter H. Wellhouse, Ithaca, N. Y. 



This tingid was originallj' found June 18, 1917, four miles southeast 

 of Tiffin, Ohio, on four or five Crataegus trees by Carl J. Drake and the 

 adult was described March, 1918, by E. H. Gibson (Trans. Amer. 

 Ent. Soc. 44: 69-104). Professor Drake informs the writer that he 

 found one of these trees very badly infested with thousands of speci- 

 mens feeding on it and that he found eggs, nymphs and adults on this 

 same tree in August, 1918. There is no other record of this species 

 having been found. The writer has observed it during the past year 

 in several localities about Ithaca. 



Hosts 



It seems to confine its attack to those species of Crataegus that have 

 an abundance of pubescence along the veins on the lower sides of the 

 leaves. I have found it breeding in abundance on Cratoegus neoflu- 

 vialis and to some extent on C. albicans and C. punctata. Those 

 species with smooth leaves, such as C. pndnosa, C. crus-galli and C. 

 oxyacantha, even when their branches were intermingled with those of 

 trees which were badly infested, revealed no nymphs or eggs. 



IXJURY 



In a large thicket of CraUrgus neojluvialis trees near the Cornell 

 University campus the leaves were so discolored by the end of July 

 that they attracted the attention several hundred yards away. By 

 the middle of August the leaves were falling and the branches were 

 ])arc by September 1. No fruit matured on these trees. A few scat- 

 tered trees of this species in other directions from the city were also 

 badly infested. Individual trees of Cratagiis albicans and C. punctata 

 showed an occasional branch Ijadly infested and with leaves discolored. 

 The injury is caused l)y the nymphs and atlults jiuncturing the under- 

 surface of the leaf and sucking the sap, thus causing at first a mottled 

 effect due to the pale areas arountl the feeding punctures, while later 

 the leaf turns brown and falls to the ground. Ornamental jilantings 

 of Crataegus in parks and gardens may be rendered unsightly and 

 weakened by this injury. 



' Contribution from the entomological laboratory, Cornell University, Ithaca, 



N. Y. 



