3 
white flies, as well as the scale-like larve, are provided with sucking 
mouth parts. Ina short time after the emergence of the adult from 
the pupa case, the body, legs, and wings become covered with a white, 
waxy substance which gives this, as well as other species of the genus, 
a characteristic floury appearance. The adults feed nearly contin- 
uously during their existence. If deprived of food, they will rarely 
live for a longer period than three days under ordinary temperature 
conditions. The longest recorded length of life of one of these insects 
in the adult condition is thirty-six days, but it seems probable that the 
average ‘ength of adult life is much greater than this instance would 
indicate. The largest number of eggs which an adult white fly is 
positively known to have deposited is 129, but this number is probably 
below the average. Indeed, the specimen which produced this num- 
ber of eggs with little doubt deposited over 50 others which were not 
recorded. The number of eggs deposited per day by an adult female 
white fly in a laboratory has been found to average very nearly four. 
Probably in the warmer temperature of a greenhouse this number is 
greater by one or two eggs per day. These observations, even though 
falling short of showing the normal increase in numbers of this spe- 
cies, emphasize the importance of a remedy which will, above all, 
destroy the adults and check at once the rapid deposition of eggs. A 
pecularity of the egg-laying habits of this and some other species of 
white fly is the tendency to deposit the eggs in a circle while feeding, 
using the beak asa pivot. These circles, when completed, are about 
14 mm. in diameter and usually contain from 10 to 20 eggs each. On 
the more hairy leaves groups of eggs of this kind are less frequently 
met with than on those which are more nearly smooth. The majority 
of the adults are found upon the upper and newer leaves of the food 
plant. They are almost invariably found upon the underside of the 
leaves, and it is here that nearly all the eggs are deposited, although 
many are found upon the tender stems and leaf petioles and a very 
few scattering ones on the upper surfaces of the leaves. 
The eggs are distinguishable with difficulty by the naked eye, being 
but one-fifth of a millimeter, or one one hundred and twenty-tifth of an 
inch, in length. They are more or less ovoid in form and suspended 
from the leaf by a short,slender stalk. With ordinary greenhouse 
temperatures the eges hatch in from ten to twelve days. The newly 
hatched insect is flat, oval in outline,and provided with active legs and 
antenne. It rarely crawls farther than one-half.inch from the empty 
egoshell before settling down and inserting into the tissue of the leaf 
its thread-like beak. After feeding for five or six days, the insect is 
ready to molt its skin. The second and third stages are much alike, 
except in size, and differ principally from the first stage in that the 
legs and antenne are vestigial and apparently functionless. These two 
stages occupy from four to six days each. 
