INSECTS AFFECTING PARK AND WOODLAND TREES 1 65 



grown caterpillars range from i inch to i i| inches in length. The pale 

 brown head is mottled with dark brown and has reddish brown hairs 

 scattered over its surface. The body is dark brown or black with numerous 

 fine, dull orange or gray spots over the surface, which are most pronounced 

 on the second, third and fourth segments. Long reddish brown, finely 

 barbed hairs arise from all the tubercles, and white branching hairs from 

 the upper side of the latter tubercles on segments 4 to i 2 inclusive. These 

 white hairs form elongated white spots along each side and are (Hie of the 

 most striking characteristics of this caterpillar. The subdorsal and lateral 

 tubercles on segments 4 to i 2 inclusive are covered with tine, short spines 

 of uniform length. There is a bright red retractile tubercle on the top of 

 the loth, and also one on the i ith segment. 



The pupae are -;4 inch in length, dark brown in color and with fine, 

 yellowish brown hairs scattered over the surface. 



Life history. The winter, as previously stated, is passed by the partly 

 grown caterpillars in conspicuous webs on terminal twigs. They begin 

 work in the spring, feeding downward from the tip of the branches, leax'ing 

 the naked twigs and the gray tents at their extremities, conspicuous evi- 

 dence of their presence. The entire leaf, except the midrib, is devoured, 

 except that in those like the sycamore maple, all the larger ribs are 

 untouched. The caterpillars when numerous may devour not only buds, 

 leaves and blossoms, but even green fruit. riuy are gregarious till nearly 

 full grown, when they disperse to some extent, and this spreading is more 

 marked when the fooil supply on a tree becomes exhausted. Several cater- 

 pillars frequently pupate in a common cocoon within the leaves at the tip 

 of the branches, and sometimes in masses under fences, clapboards or on 

 the trunks and larger branches of trees. The webs of the brown tail moth 

 may be easily distinguished from those of the tent cater])illar or the fall 

 web worm. The tent caterpillar makes its webs in the forks of the branches, 

 whereas those of the brown tail moth occur at the tijjs. The fall web 

 worm rarely occurs on pear, which is a favorite food plant of the brown tail 

 moth, and the former usualh' makes a much larger, more open web than 



