454 The Ohio Naturalist [Vol. VI, No. 4, 



(Vitis vulpina L). The webs were abundant everywhere upon 

 the choke-cherry and the common wild black cherry, some trees 

 of the latter kind having nearly half of their foliage destroyed. 

 Willows were also nearly always populated by a few or many 

 broods. The few walnut trees were literally defoliated, and this 

 will be the subject of the next topic. Elm, box-wood and 

 hackberry were frequently infested but never to the same 

 extent as the previously named trees. In only two instances 

 did I observe the worms feeding upon the wild grape, and then 

 only when the grape leaves grew in among the leaves of willow 

 and choke-cherry. I did not observe a single instance of the 

 worms feeding upon the poplars at the Point. This is quite at 

 variance with other observations in which poplars of all kinds 

 were generallv mtich infested. Thus, in Riley's report upon 

 the Web worm in Washington in 188G ("Our Shade Trees and 

 Their Insect Defoliators") Populus balsamifera L) and P. trem- 

 uloides Mx. are named among the trees that suffered most. Both 

 these poplars occur at Cedar Point but no webs were observed 

 upon them. 



Following I give the first five trees named in Riley's list of 

 108 food plants for Washington. These are arranged according 

 to the damage suffered. Negundo aceroides Moench (Box Elder), 

 Populus alba L (European White Poplar), P. monilijera Aiton 

 (Cottonwood), P. balsamifera L (Balsam Poplar). 



The same report further states that poplars, cottonwoods 

 and the ranker growing willows were the principal subjects of 

 attack in 18SG in New England. 



Of the species of trees attacked at Cedar Point, four, walnut, 

 wild black cherry, choke-cherry and willow appeared to be the 

 favorite food of the worms, and these are respectively 41, 75 

 and 14, in Riley's list. (The common wild cherry is not named 

 in his list, and its place among the above figures is indicated by 

 a question mark.) Again, of all the species of plants named by 

 Riley forty-two genera and about twenty-six species are found 

 at Cedar Point ; but of these only eight were observed to be used 

 as food by the worms. 



Throughout the State generally, so far as my limited observa- 

 tions extend, and from a few other reports, the common wild 

 black cherry is the tree most generally attacked; but walnut, 

 elm, hickory, pear, apple, sugar and silver maple, all suffer more 

 or less. Of these, walnuts, when attacked suffer most, as the 

 following topic will show; and Mr. Cotton, Assistant Inspector 

 of Orchards and Nurseries, has informed me of similar conditions 

 in other parts of the State. 



The following observation is interesting as it vshows the dis- 

 crimination with which the female moth selects the food plants 

 upon which she deposits her eggs. One day I observed a web 



