INSECT PESTS OF OHIO SHADE AND FOREST TREES 315 



cycle may be somewhat shortened during the favorable conditions 

 of summer. Under Ohio conditions the adults begin to seek their 

 winter quarters by mid-October. 



Nature of work. — The harm inflicted by the sycamore lace bug 

 consists in the sapping of the foliage by the feeding insects clus- 

 tered on the underside of the leaves. Both nymphs and adults are 

 active in this respect. When the attack is severe a whitening and 

 deadening of the fohage results. (See Plate LXI, Fig. 4.) 



Food plants. — The sycamore lace bug, in so far as is known, 

 attacks sycamores only of which there are two species in Ohio: 

 the common sycamore or button wood (Platinus occidentalis) and 

 the European form (P. acerifolia). 



Distribution. — This insect is found throughout the greater part 

 of the United States east of the Rocky Mountains. 



Natural enemies. — The natural enemies reported by Waid are 

 as follows: a Chrysopid, assassin bugs (Reduviidae) , spiders, a red 

 mite, and a predaceous heteropteran {TrliMeps insidiosus, Say). 



Control. — After a series of experiments which involved the use 

 of kerosene and crude-oil emulsions, nicotine sulphate, concentrated 

 lime-sulphur and fish-oil soap solutions, Waid decided that of the 

 materials tested, fish-oil soap used at the rate of 1 pound to 6 gallons 

 of water was most satisfactory. Since the naterial kills by contact 

 only and since the insects as previously statecJ inhabit the underside 

 of the leaves, particular care should be taken to direct the spray 

 upwards and to do the most thorough work possible. At least 150 

 pounds pressure and preferably nozzles of the large disk type or the 

 spray gun should be used. 



