278 OHIO EXPERIMENT STATION: BULLETIN 332 



the host. By the end of June they have reached maturity and after 

 seeking a sheltered nook, such as a crevice in the tree, in cracks of 

 fences, etc., transform to the pupal stage. The length of this period 

 is about 3 weeks and at the end of this time the moths emerge. 

 They are attracted in tremendous numbers to strong lights and in 

 the infested territory the light and line poles in the immediate 

 vicinity of arc lights sometimes are almost plastered with the bodies 

 of the moths. The eggs are deposited in the position and manner 

 described. The eggs hatch in late summer and the young larvae, 

 feeding in colonies on the tender terminal leaves, web them together 

 to make the winter retreat. Thus it will be seen that there i& but 

 one brood per year. 



Both the male and the female moths fly, and because of this 

 fact the distribution of the species is much more rapid than that of 

 the gipsy moth. Masters of sailing vessels have reported encounter- 

 ing swarms of the moths from 75 to 100 miles out at sea and 

 authentic records exist of the capture of moths 42 nautical miles 

 from the nearest infested territory. 



Nature of injury. The newly-hatched caterpillars feed at first 

 upon the epidermis of the leaf, but as they grow older the entire 

 leaf structure excepting the veins is consumed. In the spring of 

 the year when the partly-grown caterpillars leave their retreats and 

 begin feeding, the expanding buds are devoured, and if the tree is 

 well supplied with caterpillars it may be kept in a defoliated con- 

 dition during the entire summer. Successive defoliations by the 

 caterpillars or the prevention of the development of the foliage is 

 quite capable of causing the death of the host as has actually hap- 

 pened in thousands of cases in New England. 



Another type of injury is the rash or. eruption of human beings 

 caused by the spined hairs of the caterpillars and to a less extent 

 caused by the brown hairs from the abdomen of the moth. The 

 trouble is commonly referred to as "brown-tail rash," and with the 

 more susceptible persons is so annoying as to preclude their dwell- 

 ing within the bounds of infested territory. Not only is the irrita- 

 tion of an external nature but internal as well, since the breathing 

 of the floating and broken hairs irritates the tissues of the lungs 

 and serious results occasionally follow. 



Food plants. The brown-tail moth is a much less omnivorous 

 feeder than the gipsy moth, though most of our fruit and deciduous 

 forest trees are attacked and occasionally herbage is eaten. Coni- 

 fers are not attacked and seldom is hickory, ash, chestnut or birch 

 injured. 



