i6o Control of Parasites 



by threads. The white or }ello\vish cocoons are spun in 

 the leaves on the tree or on the ground, in crevices of bark 

 or other shelter. No tents like those of the apple tent- 

 caterpillar are made, but thin carpets are spun along the 

 bark, and occasionally several terminal leaves are included 

 in the web. The moths are recognized by their rusty brown 

 or buff color; they fly in July, and lay their eggs on the lower 

 twigs, encircling them in belts, covered with a brownish 

 protective covering. 



They feed not only on maple, but on a variety of species, 

 and can become very destructive. 



Collecting the egg clusters, or cutting off the twigs with the 

 egg clusters and burning them can be advantageously prac- 

 tised with young trees in July or August. Crushing the 

 clusters of young caterpillars, or else brushing, shaking, 

 and jarring them down and preventing their re-ascent by a 

 band of cotton batting, dendrolene, etc., or swabbing their 

 nests in early morning with kerosene is effective in April 

 to May, or else thorough spraying with kerosene emulsion 

 or whale-oil soap or arsenite,' as the leaves unfold. The 

 collection of cocoons may also be resorted to, but care should 

 be taken not to destroy them until the parasites have been 

 hatched from them. 



Fall Web-worm. A familiar sight during July, August, 

 and September are the conspicuous silken webs, nests of 

 young, pale yellow, black-headed, black-dotted and striped, 

 hairy caterpillars, which, feeding gregariously, spin one or 

 several leaves together, enlarging the web as they grow 

 until the foliage of the whole limb is included. In southern 

 latitudes, two broods appear in a season, the first one issuing 

 in June. The dark brown pupa is spun in a silken cocoon 



' Boil one pound white arsenic with two pounds freshly slacked lime in 

 one gallon of water for forty minutes and dilute in fifty gallons of water. 



