THE GIPSY AND BROWN TAIL MOTHS 



17 



The full grown caterpillars [pi. 2, fig. 3], range from 1 inch to 

 1 \ inches long. 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 lateral tubercles on segments 4 to 12 inclusive. 

 These white hairs form elongated white spots along each side and 

 are one of the most striking characteristics of the full grown cater- 

 pillar. The subdorsal and lateral tubercles on segments 4 to 12 

 inclusive are covered with fine, short spines of uniform length. 

 The bright red retractile tubercles on the top of the 10th and nth 

 segments are also visible as described above. 



The pupa is f inch long, dark brown in color and with fine, yellow- 

 ish brown hairs [pi. 2, fig. 4] scattered over the surface. 



The close, firm webs [pi. 2, fig. 7; pi. 10] of this species are 

 also very characteristic. They are 4 to 6 inches long and occur on 

 the tips of the smaller twigs, remaining there throughout the winter. 



Life history. The winter is passed by partly grown caterpillars 

 in the peculiar webs on the terminal twigs. They begin work 

 in the spring, feeding downward from the tip of the branches, 

 leaving the naked twigs and the gray apex at their extremities, 

 conspicuous evidence of their presence. All the leaf but the midrib 

 is devoured except that in the case of trees like the sycamore maple, 

 the larger ribs also are untouched. The caterpillars when numer- 

 ous attack not only buds, leaves and blossoms, but even green 

 fruit. They are gregarious till nearly full grown, when they dis- 

 perse to some extent, and this spreading is more marked when 

 the food supply on the 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 caterpillar, Malacosoma americana 

 Fabr., or the fall webworm, Hyphantria textor Harr., 

 both common native species, since the tent caterpillar makes its 

 web in the forks of the branches, whereas those of the brown tail 

 moth occur at the tips. The fall webworm rarely attacks pear or 

 hard maple,' both of which are mqre or less favorites of the brown 

 tail moth. The former makes a much larger, more open web 

 than the latter. Moreover it is never firmly attached to the twig 



