20 



DANGER OF SPREAD OF GIPSY AND BROWN -TAIL MOTHS. 



addition to the longer ones, which give the tubercles when magnified an appearance 

 like velvet. The head of the larva is pale brown with darker mottlings. 



The young larvae are of a blackish color covered with reddish brown hairs. The 

 head is jet black. Close examination will show projecting from the back of the 

 fourth and fifth abdominal segments a large tuft of reddish brown hairs, and on the 

 middle line of the ninth and tenth segments is an orange or reddish tubercle which 

 may be withdrawn into the body. After the second spring molt the larva is about 

 three-eighths of an inch long, the yellow markings on the body are more apparent, 

 and the brown tufts on the back less prominent, while the band of white dashes along 

 the sides, characteristic of the full-grown larva, is noticeable. 



The pupa. The full-grown larva spins a cocoon of grayish silk, which is very loose 

 in its construction and is so far from being compact that the pupa may be readily 

 seen through it. The pupa itself is about five-eighths of an inch long, dark brown in 

 color, with a conical spine at the end of the abdomen bearing a cluster of minute 

 hooks at the tip. Smooth, yellowish brown hairs are found scattered over the abdomen 

 and the top of the thorax. 



The cocoons are apparently spun by preference among the leaves at the tips of 



branches, and often a dozen or 

 more larvae will spin a common 

 web within which each individual 

 forms its own cocoon and trans- 

 forms to pupa. The cocoons are 

 also found under fences and be- 

 neath the edges of clapboards. Mr. 

 Kirkland has seen a mass of co- 

 coons nearly 2 feet across in the 

 cornice of a house in Somerville. 



The adult, or moth. The moths 

 (fig. 6, at left) are pure white, the 

 end of the abdomen being brown- 

 ish, and both sexes bear at the tip 

 of the abdomen, more conspicuously 

 with the female, a tuft of brown 

 hairs, almost globular in form, from 

 which comes the name brown-tail 

 moth. It is the only moth occur- 

 ring in America to which this de- 

 scription applies, and is therefore 

 inches, and the male is smaller. 



FIG. 6. The brown-tail moth (Euproctis chrysorrhoea): Fe- 

 male moth above, male moth below, larva or caterpillar 

 at right. Slightly enlarged. (From Howard.) 



unmistakable. The female expands about 



Seasonal History. 



The moths fly in New England from the 1st to the 20th of July, the time varying 

 with the condition of the season. In 1898 the height of the flying season is said by 

 Fernald and Kirkland to have been July 16, in 1899 July 8, and in 1902 July 14. It 

 is a night-flying insect, and only a few are ever seen on the wing in the daytime. 

 Soon after sunset a few begin to fly, the number increasing as it grows dark, and from 

 10 o'clock to midnight they swarm to the greatest extent. They are strong flyers, and 

 are attracted to light. So great have been their numbers in the infested region 

 that the sides of red brick buildings near electric lights have appeared perfectly 

 white. It is at this time that the great spread of the species occurs, and the reason 

 that the direction of the spread has been greatest toward the northeast has been the 

 fact that the prevalent night winds at that time of the year seem to have been from the 

 southwest. Aside from actual flight, the species has spread by being carried in the 

 moth condition on railway trains and on vessels. Captains of vessels have reported 

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