244 OHIO EXPERIMENT STATION: BULLETIN 332 



Banding with sticky barriers also is used. Because the cater- 

 pillars have a tendency to release all holds and drop to the ground 

 if the tree is sharply jarred, advantage of this peculiarty is taken 

 by some and the trees banded before the caterpillars again find their 

 way to the upper portions. The method is said to possess consider- 

 able merit. Tree tanglefoot or materials having similar properties 

 is satisfactory for the banding. 



However, the use of the spraying machine with all its modern 

 developments loaded with a non-burning arsenical constitutes under 

 most conditions the most efficient and satisfactory control measure. 

 Arsenate of lead at the normal strength is effective, but as with 

 most leaf -destroying pests, the spray should be applied when the 

 caterpillars begin feeding. As indicated in the life history notes, 

 this occurs in early spring with an expansion of the foliage. 



THE OAK TUSSOCK CATERPILLAR 



(Halisidota maculata Harr) 



During the last 2 years the oak tussock moth has been a very 

 common insect in Ohio and much damage in the aggregate has been 

 done ; but, due to the fact that the caterpillars feed scatteringly, it 

 has not attracted any great amount of attention. Moreover, our 

 detailed information concerning it is meager. 



Description. The larval form is about the only stage in which 

 the pest is seen with any degree of frequency. When full grown 

 it is about 1% inches long, the head being shiny black and the 

 ground color of the body dull black. The body is covered with well- 

 defined short tufts of hair, on some individuals the tufts being 

 white and on others having a decidedly yellowish cast. The short 

 tufts extending in a row down the middle of the back are darker 

 and sometimes almost black. Pairs of slender black tufts almost 

 three times as long as the tufts just discussed arise upward from 

 the upper part of the third thoracic segment and the eighth abdomi- 

 nal segment ; a pair of similar tussocks intermingled with black and 

 white extend upward from the second thoracic segment and laterad 

 of the tussocks on the two thoracic segments project white tussocks 

 of slightly inferior length. (See Plate XXXVI, Fig. 1.) 



All the legs have a distinct brownish cast. The spiracles are 

 strikingly pure white. 



Life history and habits. So few definite data are known con- 

 cerning the life cycle and habits of this pest under Ohio conditions 

 that no attempt will be made to enter into a detailed discussion of 

 them. The larvae are most abundant, however, during September, 

 though they sometimes may be observed in considerable quantity 

 in October. 



