10 



BULLETIN 833, U. S. DEPARTMENT OF AGRICULTURE. 



where the terminal growth has been badly distorted previously as a 

 result of their work. Females have been noted to return to such 

 plants from which they have emerged and deposit eggs thereon. 

 Even though they were repeatedly disturbed, they would return 

 quickly and continue deposition. On many occasions it was found 

 that when these young tips were separated and examined, the eggs 

 would be present in greater numbers between the folds of the new tissue 

 than on the neighboring exposed surfaces. 



Incubation. — Observations, as given in Table II, show that the in- 

 cubation period varies from 3 to 16 days. The time of incubation 

 may be affected by the season of the year. 



Table II. — Length of egg period. 



Cage. 



Host plant. 



De- 

 posited. 



Hatched. 



Length, 



Number 

 deposited. 



October Frost 



Snow Queen 



Silver Wedding... 



Golden Glow 



Harvard 



Esanath 



Snow Queen 



Monrovia 



Martha Saunders. 

 Gold Chadwick... 



Esanath 



Monrovia 



.....do 



do 



Dr. Enguehard 



Pompon 



Silver Wedding 



Dr. Enguehard 



Dr. Tool 



Mrs. R. N. McLuckie. 



Margaret Bissett 



Silver Wedding 



Men.sa 



Silver Wedding 



Golden Wedding 



1917. 



Apr. 2 



Apr. 3 



Apr. 4 



A pr. 5 



Apr. 6 



Apr. 7 



Apr. 10 



Apr. 12 



Apr. 13 



Apr. 16 



Apr. 17 



Apr. 20 



1918. 

 /Jan. 31 



lEeb. 1 



...do 



Feb. 2 

 Feb. 11 

 Feb. 28 

 Mar. 1 

 Mar. 4 

 Aug. 20 

 Aug. 27 

 Aug. 29 



..do 



..do 



Sept. 5 

 Sept. 21 



Apr. 7 



Apr. 8 



Apr. 9 



Apr. 10.... 

 Apr. 11.... 

 Anr. 12.... 

 Apr. 15.... 

 Apr. 17.... 



Apr. IS 



Apr. 21.... 

 Apr. 22.... 

 Apr. 25 



}Feb. 9 



Feb. 7 



do 



Feb. 15-19. 



Mar. 6 



Mar. 6-10.. 



Mar. 9 



Sept. 6.... 

 Aug. 30... 

 Sept. 4-14. 

 Sept. 6.... 

 Sept. 6-14. 

 Sept. 10-14 

 Sept. 24... 



Day a. 

 5 

 5 

 5 

 5 

 5 

 5 

 5 

 5 

 5 

 5 

 5 

 5 



6 



5 



4-8 



11 



3 



6-16 



8 



8-16 



5-9 



3 



No records. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 



Do. 



Do. 



25 eggs. 

 No records. 



Do. 



Do. 



Do. 

 34 eggs. 



19 eggs. 

 5 eggs. 



20 eggs. 



24 eggs. 



25 eggs. 

 135 eggs. 



Development. — The development of the larva within the egg can be 

 made out easily. In the newly laid egg the nucleus, which is reddish 

 in color, is rather central, but shows a slight tendency to be located 

 toward the anterior end. There are approximately 18 yolk bodies 

 present which are arranged in a row of 9 on each side. The rows do 

 not extend quite to the posterior end of the egg. As development 

 proceeds the red pigment or nucleus moves to one side of the egg, 

 which later is apparently the ventral surface. In the meantime the 

 yolk bodies collect in a mass near the nucleus. At each end the small 

 air spaces, which at first are relatively small, later become much in- 

 creased in size. The segmentation then begins to appear, with a 

 simultaneous contraction of the entire contents. A redistribution of 



