396 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



XANTHONIA VILLOSULA MELSH. INJURING FOREST TREES 



(Coleoptera, Chrysomelidae) 

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



During the summer of 1918 a number of different forest trees about 

 Ithaca were injured by small brown leaf beetles. They were deter- 

 mined as Xanthoma villosula Melsh. by Mr. Charles W. Leng. The 

 writer first noticed them feeding on the leaves of Crataegus on June 

 27, the leaves on a few small trees being almost completely riddled 

 by them. A few days later they were seen feeding on other trees in 

 a woodlot near Cornell University and soon they were found to be 

 quite generally distributed in wooded areas about Ithaca. Small 

 trees with foliage near the ground were often found to be nearly defoli- 

 ated and occasionally a large tree had most of its leaves perforated 

 with their feeding holes. 



This insect was described by Dr. F. E. Melsheimer in 1847. It was 

 reported by Mr. J. Stauffer of Lancaster, Pa., as "committing heavy 

 depredations" on grape-vines in July, 1865. The injury was proba- 

 bly only local since there seems to be no other account of it. The 

 beetles have been taken by collectors and recorded in systematic papers 

 quite often, but its life-history and habits seem to be unknown. Dr. 

 J. B. Smith stated that it is common in New Jersey on oak and hazel. 

 Mr. Chittenden found it on leaves of hickory. Mr. W. S. Blatchley 

 says it was beaten from hazel and oak in Indiana. 



The hornbeam (Carpinus caroliniana Walt.) and the ironwood 

 trees {Ostrya virginiana Willd.) seemed to be most frequently attacked 

 last summer, but the writer found it also feeding on the leaves of Cra- 

 tcegus punctata, shag-bark hickory {Carya ovata), hard maple (Acer 

 saccharum) , linden {Tilia americana), white oak (Quercus alba), wild 

 grape (Vitis riparia), wild blackberry (Rubus sp.), witch hazel (Ham- 

 amelis virginiana) , wild rose, Waldstenia fragarioides, and wild straw- 

 berry (Fragaria virginiana) . 



The adults were found feeding on the leaves from June 27 until 

 August 2 at Ithaca. Their feeding habit is quite characteristic. They 

 cut a chain of small holes close together on the leaf, leaving only a thin 

 cross bar of leaf tissue between the holes. The hole which forms each 

 link in the chain is seldom more than one millimeter in diameter. The 

 beetles drop quickly to the ground when disturbed and are readily 

 beaten down into a net. They vary in color from brown to black, 

 some being entirely brown, some black and a few are part brown and 

 part black. The writer has found brown ones and black ones mating 



