xxxiii, '22 1 ENTOMOLOGICAL NEWS 199 



upward and forward. Although possessed of fully developed 

 wings, they have seldom been seen to fly and then only for short 

 distances. When disturbed they will run rapidly around the 

 stem or to some place of hiding. They are often found close 

 down in the axils of newly opening leaves. 



These insects possess the .ability to puncture the skin. The 

 writer while working with them has often felt a very per- 

 ceptible stinging sensation from their bite on the back of the 

 hand, neck or other place where the skin is tender. 



ENEMIES. 



One of the factors limiting the increase in numbers of the 

 bay thrips is that it is preyed upon by other insects. At least 

 two of these enemies have been found, one an internal hymen- 

 opterous parasite and the other a predaceous Anthocorid. 



The first of these is Tctrastichns .?/>., 5 apparently an uride-- 

 scribed species, and a representative of a genus not known 

 before from Thysanoptera in this country. Internal parasites 

 of thrips while very rare, have been reported in a few cases. 

 Parasitized specimens of this thrips were collected on bay trees 

 in September, 1921, and the adults bred from them in the 

 laboratory. The eggs are laid by the adults in the bodies of 

 the larval stages of the thrips. After a few days the thrips 

 dies and the body becomes dried and swollen. About a week 

 later the small wasp-like parasite emerges from a hole cut 

 through the body \vall on the dorsal surface near the end of 

 the abdomen. 



The second of these is Anthocoris sp.? a small predaceous 

 insect, which was found sucking the juices from the larval and 

 pupal stages of the thrips. While perhaps not so important a 

 factor in control as the internal parasite, still these Anthocorids 

 will destroy a large number of thrips. These two insects 

 undoubtedly are largely responsible for keeping the thrips from 

 increasing and doing a large amount of injury to the bay trees. 



EXPLANATION OF PLATE IX. 



Cryptothrips laurcli n. sp. A. Head and prothorax. B. Antenna 

 enlarged. C. Tip of abdomen showing tube and hairs. D. Second 

 stage larva. E. Egg. 



5 Determined by A. B. Gahan of the Bureau of Entomology. 

 6 Determined by W. L. McAtec, of the Bun-au of Entomology. 



