6 BULLETIN 1225, U. S. DEPARTMENT OF AGRICULTURE. 
to grow unhindered they attain great size and become remarkably 
beautiful (fig. 4). 
When grown for ornamental hedges along streets or in dooryards, 
however, where it is necessary to keep the trees pruned back regularly, 
they suffer considerable damage from the thnps. They suffer also 
when the trees are cut back to procure material for distillation. The 
insects collect in great numbers around the cut ends and feed upon 
the plant tissues. In addition they destroy the buds (PL II) and 
new growth when put forth by the trees, and even work in the 
limbs (PL III), causing the bark to crack (PL IV, A) and later the 
limbs to become deformed (PL V). Their chief damage is probably 
to the buds, and when present in any great number they prevent 
the trees from putting forth very much new growth, without which 
Fig. 4.— Row of camphor trees planted as a windbreak for a citrus grove. When uninjured the trees make 
a beautiful hedge and are not seriously attacked by the camphor thrips. 
camphor production is cut off. As will be shown later, the usual 
pruning practices had to be changed. Instead of pruning the trees 
promiscuously and cutting the limbs back to stubs it was found 
necessary to cut the trees off at the level of the ground. 
DESCRIPTION. 
ADULT. 
The original description of the adult (PL I, A) was by Prof. J. R. 
Watson (1), as follows: 
Cryptothrips floridensis, new species. 
Measurements: Head, length 0.25 mm., width 0.20 mm.; prothorax, length 0.17 
mm., width 0.34 mm.; mesothorax, width 0.40 mm.; abdomen, width 0.44 mm.; 
total length of insect, exclusive of antennae, 1.89 mm.; tube, length 0.14 mm., width 
at base 0.075 mm.; antennae, 1, 36 m; 2, 51.7m; 3, 77.6 n; 4, 78 /x; 5, 65 /x; 6, 63 m; 7, 
54.5^; 8, 40 m; total 0.42 mm. 
General color, black, no purple pigment; tarsi dark brown and antennae yellow. 
