26 ' NEW YORK STATE MUSEUM 



Description. The caterpillar can be easily distinguished from the 

 common apple tent caterpillar by the row of somewhat diamond- 

 shaped, whitish spots down the middle of the back and by its feeding 

 mostly upon oak, sugar maple and poplar, trees rarely attacked by 

 the apple tent caterpillar. 



The egg belts are also characteristic in being smaller than those 

 of the apple tent caterpillar and with the ends terminating rather 

 abruptly. The light brown protective covering usually has one or 

 two transverse wrinkles or depressions. 



The white or yellowish white cocoons are frequently spun in leaves 

 on the trees or on the ground and also occur in crevices of the bark, 

 under stones, in fence comers and in almost any convenient shelter. 



The moths are light buff colored insects with a wing spread of one 

 and one-eighth to one and one-fourth inches and with markings of 

 darker brown. The male may be recognized by its richer coloring, 

 smaller size and feather}^ antennae. 



Life history and habits. The well-developed caterpillars winter 

 within the egg and with the appearance of warm weather begin to 

 emerge and commence feeding upon the imfolding leaves. There 

 may be variations of a month or so in the hatching; this species is 

 decidedly later than the more familiar apple pest. When not feeding 

 the young caterpillars assemble in clusters on the limbs and as they 

 increase in size, molt from time to time, leaving their cast skins in 

 small clusters on the bark. The latter frequently give rise to the 

 report that many of the pests have succumbed to frost or other 

 adverse climatic conditions. Early injuries are confined mostly to 

 the tops of the trees, and as the pests increase in size the tendency is 

 to crawl farther down the trunks and to form larger clusters during 

 the resting periods. A serious infestation means the stripping of the 

 trees while the caterpillars are still partly grown and a forced migra- 

 tion for food. The full-grown larvae obey a natural impulse and 

 crawl in all directions seeking for suitable shelters in which the final 

 transformations may take place. The pupal stage lasts about two 

 weeks, the moths appearing the latter part of June and during July, 

 mostly in the latter month. The eggs are soon laid and remain upon 

 the twigs unhatched imtil the following spring. 



Food plants. Various oaks in the Southern States and on Long 

 Island, the sugar maple and the American poplar, Populus 

 tremuloides, are favorite food plants. In the Adirondacks the 

 pin or bird cherry, ehns and Comus close to poplars were badly eaten 

 or nearly stripped, while red maple and birch were almost exempt 

 from injury unless close to defoHated trees. All the coniferae were 



