52 THE GYPSY MOTH APPENDIX. 



place in from three to ten days after pairing, depending 

 upon the temperature, warm weather hastening and cold 

 weather retarding this process. Each female deposits from 

 two to four egg-clusters at intervals ranging from a few 

 hours to three days. 



The Egg. The general appearance of the egg (Plate 1, 

 Fig. 1) so closely resembles that of P. serieventris, both in 

 size and markings, that the separation of the species in this 

 stage is extremely difficult. The eggs are deposited in clus- 

 ters composed of a single layer. From ten to thirty-live 

 eggs are placed in a cluster, each egg resting on its smaller 

 end, and connected with the adjacent eggs by means of a 

 varnish-like cement. The form of the egg is nearly ellip- 

 soidal, slightly tapering toward the lower end, but not as 

 caldron-shaped as in P. serieventris. Length, 1 mm. ; width, 

 .8 mm. Top slightly flattened, and surrounded by a row of 

 ten or twelve capitate spines, arranged around the margin 

 of a circular cap. The surface of the egg is covered with 

 minute spiny projections, not abundant at the lower end of 

 the egg. When first laid the eggs have a pearly white 

 color which soon changes to a deep bronze. The period of 

 incubation extends over eight or ten days, according to the 

 temperature. The circular cap at the top of the egg is 

 pushed off by the young bug at the time of hatching, but 

 usually remains attached at one point. 



First Stage. The newly hatched bug (Plate 1, Fig. 2) 

 is 1.7 mm. in length. Form ovate. Head and thorax dark 

 seal brown, abdomen vermilion. The head is much wider 

 than long, closely appressed to the prothorax, and bears 

 large compound eyes, which, from their relative size, are 

 quite conspicuous. Antennre four jointed, basal joint stout, 

 nearly concealed beneath the margin of the head. Second 

 joint cylindrical, three times as long as basal joint ; third 

 joint cylindrical, three-fourths as long as second joint ; 

 fourth joint one-half longer than second joint and consider- 

 ably dilated ; all the joints bear scattering hairs. The ter- 

 minal joint is seal brown in color, the other joints being 

 copper colored. 



