516 CITRUS FRUITS AND THEIR CULTURE. 



June 22, 1901, had upon it upwards of 20,000 eggs. While 

 so many eggs upon such a space is beyond the average, it 

 is by no means rare, and I have sometimes seen the number 

 exceeded. 



Hatching occurs in from three to twenty days, ac- 

 cording to the weather. 



The larva passes through four moults before reaching 

 the pupa stage. When first hatched the insect is about 

 1-80 of an inch in length (0.3mm), of a pale greenish yel- 

 low color, with two darker yellow spots on the back of the 

 abdomen. There are four conspicuously long bristles at 

 the posterior part of the body and six long ones on the 

 anterior end with minute ones along the sides, each aris- 

 ing from a tubercle. Antennae, three or four jointed. 

 Four eyes, dark reddish. Legs short, six in number. 

 Mouth parts consist of a long sucking tube. On the 

 dorsal side of the last abdominal segment is a subovate, 

 brown colored opening, the vasiform orifice. Appearance 

 in second and third stage not markedly different from the 

 first, except in size and minute microscopical characters. 

 In the fourth stage the length has increased to about 6-100 

 of an inch (1.5 mm), the width to 4-100 of an inch (1 

 mm), and the conspicuous bristles have vanished; a pair 

 of persistent, minute bristles is found on the anterior 

 border, one on each side, and another pair, also minute, is 

 disposed one on each side of the anal cleft. The insect is 

 very flat and close pressed to the leaf ; the dorsum or back 

 is crossed by twelve transverse ridges, indicating the seg- 

 ments. Arising from the prothoracic region on each side, 

 extending obliquely outward and forward to the margin is 

 a distinct ridge or fold, the breathing fold. The outline of 

 the developing wings of the embryo can be distinctly seen 

 from the first. 



