INSECTS AFFECTING PARK AND WOODLAND TREES 1 43 



foliage, and in southern cities entire rows of trees may have their leaves 

 destroyed by this pest. 



Distribution. This insect is an American species and occurs from 

 Canada to Georgia and certainly as far west as Montana and Texas. It 

 appears to be more injurious in some of the southern states like Kentucky, 

 where the development of a vigorous second generation is the rule, than it 

 is farther north. 



Description. The yellowish, globular eggs [pi. lo, fig. i | are deposited 

 in clusters of i to 300, usually on the underside of the leaf. The yellow 

 changes to a dull leaden hue, due to the developed caterpillar within, just 

 before the eggs hatch. 



The recently emerged caterpillar has been described as pale yellow, 

 sparsely haired, w^ith a black head and with two rows of black marks along 

 the body, but as there is considerable variation in the color of the larva 

 later in life, it would not be surprising to find the same more or less true of 

 its earlier stages. The hairy, yellowish, brown and black marked cater- 

 pillars vary considerably in appearance. A half grown and two full grown 

 larvae are represented on plate 10, figure 2, a dorsal and a lateral view being 

 given of the latter two. The head is black and the whitish or brownish 

 hairs spring in clusters from the black and orange tubercles. 



The oval cocoon is thin and mixed with larval hairs or, where it is 

 spun at or just below the surface of the ground, particles of soil may be 

 entangled in its meshes. The brownish pupa may be recognized by the 

 swelling near its middle [pi. 10, fig. 3, 4]. 



The moth is very variable in appearance and ranges from a pure white 

 to a form much spotted with black. [ Compare fig. 5 and 6, pi. 10.] 



Identity of the insect. The extreme variability of the adult has led to 

 the bestowal of a number of scientific names on the insect, which in its 

 larval state makes the conspicuous web above described. The studies of 

 Mr H. H. Lyman led him to conclude that two species have been confused 

 under the name of Hyphantria cunea Drury. The web made by 

 the larva of the more common species in this .State belongs to H y ph an- 



