304 



THE GYPSY MOTH. 



the tenth and eleventh segments usually have a convex cap 

 of hardened reddish fluid, which may be removed with the 

 point of a needle, and beneath which the tubercle is hollow 

 to the depth of three or four mm., and filled with a reddish 

 fluid, which has an agreeable odor, but I am not able to state 

 what it is like. 



Sixth Larval Stage. — Length, 30 mm, (about one and 

 eighteen hundredths inches), immediately after molting. 

 The head is from 5.5 to 6 mm. (about twenty-two hun- 

 dredths of an inch) in width, dull or yellowish white, and 

 more or less mottled with black or brown over the top and 

 sides, with a vertical black or brown stripe on each side of 

 the clypeus. There is a great variation in the ground color, 

 and also in the amount of black or brown on the surface of 

 the head. Fine yellow hairs are scattered over the surface, 

 and the color and markings are as in the preceding stage. 



Seventh Larval Stage. — Length, from 35 to 40 mm. 

 There is no marked difference in appearance, in this stage, 

 from the preceding, except in size, and all caterpillars that 

 we have bred to this stage have transformed into female 

 moths. Only a comparatively small proportion of the cater- 

 pillars reach this stage before pupating. 



First and Last Appearance of Larvod. 



The newly hatched caterpillars of the gypsy moth have 

 been found in the field as early as April 20, and as late as 

 June 17. In the summer of 1893, Mr. H. J^. Reid found a 

 caterpillar which did not begin to pupate until September 6. 

 The feeding period of the caterpillar generally extends from 

 the first of May, to about the middle of July, but varies 

 somewhat with the season, and, in a less degree, with the 

 locality of the colony, those near the sea-shore being some- 

 what slower in development than those farther inland. 



Molts. 



In the latter part of the winter of 1893, Miss Carrie Gor- 

 don, one of the assistants at the Maiden office, observed the 

 molts of several caterpillars of the gypsy moth, taken from 

 egg-clusters which had been kept in a warm room, and thus 



