348 Report of the Department of Ektomology of the 



prematurely. The injury to prunes and cherries in California 

 through the deposition of eggs is at times very noticeable and 

 is apparently the cause of considerable dropping of fruit. The 

 incubation of the egg is of short duration and hatching occurs 

 within a week after oviposition. 



Larva. — The larva is a small, white, soft-bodied creature with 

 a single pair of eyes, and its shape and the character of its exter- 

 nal structures are represented in Fig. 3. 

 The larvae may be detected about the time 

 of blossoming when they emerge from blos- 

 som and leaf stems, and later from the sur- 

 faces of the young fruits. When Kieffer 

 pears were commencing to bloom the larvge 

 were observed in considerable numbers 

 pushing their way up through slits made 

 in the plant tissues for the reception of 

 the eggs. Their presence was plainly indi- 

 cated by the pimpling of the stems and 

 young fruits and by the appearance of tiny 

 whitish objects of indefinite shape, ren- 

 dered conspicuous by two reddish spots 

 which proved to be the eyes of the newly 

 hatched insects. By struggling and sway- 

 ing their bodies the yoiTug thrips gradually 

 release their appendages and emerge from 

 the nidi of the eggs as fragile, mite-like 

 creatures. The time consumed for the en- 

 tire process from the extrusion of its head to the release of the 

 larva from the egg shell is variable but with some individuals it 

 occupied as much as thirty to forty minutes. Upon their release 

 the larvae seek the calyx basins or the axils and rolled margins of 

 the leaves where they may be quite readily seen by a careful, 

 observing orchardist. 



The larva has mouth-parts similar in structure and function 

 to those of the mature insect, and it feeds in like manner. Com- 



FiQ. 3. — Pear Thrips 

 Larva. 



(Much enlarged) 



