8 
BULLETIN 1225, U. S. DEPARTMENT OF AGRICULTURE. 
PREPUPA. 
Average measurements of the prepupa (PI. I, E) are: Length 2.27 mm., width of 
mesothorax 0.537 mm. Somewhat smaller than the preceding stage and lighter in 
color. The blotches of pigment now appear larger and not so numerous throughout 
the body, which is whitish or almost transparent. The head and thorax are white, 
with little coloring except for the eyes, which are larger and reddish brown. The 
last abdominal segment is light brown. The legs are colorless and the antennae, 
which are short, heavy, and folded back along the head, are also colorless. The wing 
pads show as short colorless sacs. Numerous long whitish hairs appear on the antennae 
and abdomen. 
PUPA. 
Average measurements of the pupa are: Length 1.98 mm., width of mesothorax 
0.417 mm. The pupa (PI. I, F) is smaller than the prepupa, but similar in color, 
-except for the presence of a little more pigment, particularly in the head and thorax. 
The antennae are now longer but folded back along 
the head. The wing pads are longer, reaching 
about the third abdominal segment, Numerous 
long white or colorless hairs are on the legs, anten- 
nae, and abdomen. 
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MALES. 
In the larval and pupal stages the males 
are somewhat smaller than the females 
and have a distinct purple color, but 
otherwise are similar in structure and 
appearance. They occur very rarely in 
nature. 
LIFE HISTORY AND HABITS. 
METHODS OF REARING. 
The life history of the camphor thrips 
was worked out in the laboratory under 
conditions as nearly natural as possible, 
with daily observations on the insects 
infesting growing trees. The work was 
carried on in summer and also during the 
cooler weather of winter. Test tubes 
were employed as breeding cages and the 
thrips confined on small pieces of camphor 
twig. (Fig. 6.) The twigs were cut in 
lengths of about 3 inches and placed in 
water in small shell vials, the mouth of 
the vial being filled with cotton which 
surrounded the twig and held it in place. 
This vial was then dropped into a test 
~?oTUe b cimXfthX e s dingCage tllbe aild the teSt tXlbe st °PP ered witn 
cotton. The immature stages of the 
thrips were usually held on the camphor twigs by the cotton, 
but should one succeed in crawling over the cotton it was confined 
inside of the test tube and could be replaced on the twig. The adults 
would fly across on to the test tube, but would return to the twigs to 
feed and oviposit. In all experiments fresh food was given the thrips 
every few days and they were kept until they died a natural death. 
Owing to the activity of the thrips and their small size, some of 
them were lost or injured in transferring to new cages or new food. 
.COTTOAS 
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--COTTOA/ 
