12 



BULLETIN 1225, U. S. DEPARTMENT OF AGRICULTURE. 



Both in this stage and also in the pupa stage which follows they are 

 never seen on the leaves and limbs and can be found only by digging 

 into the bark. 



The duration of the prepupal stage is usually very brief, less of the 

 life of the thrips being passed in this stage than in any other. Dur- 

 ing the warm weather most of the thrips remained in this stage 

 only about 24 hours. No specimens in the breeding jars ran over 2 

 days. The average for 58 individuals was 1.17 days. During the 

 winter months this stage was passed in from 2 to 5 days, with an aver- 

 age of 3.5 days. Table 2 gives detailed records on the length of this 

 stage. 



PUPA. 



The pupal stage is passed entirely in seclusion in the bark lesions, 

 and the pupre are never seen on the outside of the tree. The thrips in 

 this state do not move about but remain quiescent, and do not feed. 

 After the final molt the adults emerge from, the bark and appear on 

 the limbs and buds. 



The pupa stage varied from 1 to 4 days in summer, with an average 

 of 2.89 days. In winter it lasted from 2 to 7 days, with an average of 

 5.35 days. Even in the colder parts of the State the pupal stage is 

 not of very great duration, for the periods of inactivity caused by 

 unfavorable weather are passed by hibernation of the adults. 



Table 2. — Duration of larval and pupal stages of the camphor thrips. 



IN SUMMER. 



Record No. 



Date 

 hatched. 



First instar. 



Date of 

 molt. 



Length 



of 

 stage. 



Second instar. 



Date of 

 molt. 



Length 

 of 



Prepupa. 



Date of 

 molt. 



Length 



of 

 stage. 



Pupa. 



Date of 

 molt. 



Length 



of 

 stage. 



ID.. 

 11.. 

 12.. 

 13.. 

 14.. 

 15.. 

 16.. 

 17.. 

 18.. 

 19.. 

 20.. 

 21.. 

 22.. 

 23.. 

 24. 

 25. 

 26. 

 27. 

 28. 

 29. 

 30. 

 31. 

 32. 

 33. 

 34. 

 35. 

 30. 



1921 

 Aug. 11 



..do 



..do 



..do 



..do 



..do 



..do..... 



..do 



..do 



..do 



Aug. 12 



..do 



...do 



Aug. 13 

 ...do..... 



...do 



Aug. 14 

 ...do.... 

 ...do.... 

 ...do.... 



...do 



...do.... 

 ...do.... 

 ...do.... 

 ...do.... 



Aug. 15 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 



Aug. 16 

 ...do.... 

 ...do.... 

 ...do.... 



1921 

 Aug. 16 

 Aug. 15 



...do 



...do 



...do 



Aug. 16 

 Aug. 15 



...do 



...do 



Aug. 16 



...do 



...do 



...do 



Aug. 18 



...do 



...do 



...do 



...do 



...do 



...do..... 



...do..... 



...do 



Aug. 17 

 Aug. 19 

 Aug. 18 



...do..... 

 Aug. 19 



...do 



Aug. 18 

 Aug. 19 



...do..... 



...do..... 



...do..... 



...do..... 



...do.... 



...do.... 



Days. 

 5 

 4 

 4 

 4 

 4 

 5 

 4 

 4 

 4 

 5 

 4 

 4 

 4 

 5 

 5 

 5 

 4 

 4 

 4 

 4 

 4 

 4 

 3 

 5 

 4 

 3 

 4 

 4 

 3 

 4 

 4 

 4 

 3 

 3 

 3 

 3 



1921 

 Aug. 20 

 Aug. 19 



...do.... 

 Aug. 20 

 Aug. 19 

 Aug. 21 

 Aug. 19 



...do.... 



...do.... 

 Aug. 20 



...do.... 

 Aug. 19 

 Aug. 20 

 Aug. 21 



...do.... 



...do.... 

 Aug. 22 

 Aug. 23 

 Aug. 22 



...do.... 

 Aug. 23 



...do.... 

 Aug. 21 

 Aug. 24 

 Aug. 22 



...do.... 

 Aug. 23 



...do.... 



...do.... 

 Aug. 24 

 Aug. 23 

 Aug. 24 

 Aug. 23 



...do.... 

 Aug. 24 

 Aug. 26 



Days. 

 ' 4 

 4 

 4 

 5 

 4 

 5 

 4 

 4 

 4 

 4 

 4 

 3 

 4 

 3 

 3 

 3 

 4 

 5 

 4 

 4 

 5 

 5 

 4 

 . 5 



1921 

 Aug. 21 

 Aug. 20 



...do.... 

 Aug. 21 

 Aug. 20 

 Aug. 23 

 Aug. 21 

 Aug. 20 



...do..... 

 Aug. 21 

 Aug. 22 

 Aug. 20 

 Aug. 22 



...do..... 



...do.... 



...do.... 

 Aug. 23 

 Aug. 24 

 Aug. 23 



...do.... 

 Aug. 24 



...do.... 

 Aug. 22 

 Aug. 26 

 Aug. 23 



...do.... 

 Aug. 24 



...do.... 



...do.... 

 Aug. 25 

 Aug. 24 

 Aug. 25 

 Aug. 24 



...do.... 

 Aug. 25 

 Aug. 28 



Days. 



1921 

 Aug. 24 

 Aug. 23 

 Aug. 22 

 Aug. 24 

 Aug. 23 

 Aug. 26 

 Aug. 22 

 ...do.... 

 Aug. 23 

 Aug. 24 

 ...do.... 

 Aug. 23 

 Aug. 24 

 Aug. 25 

 ...do.... 

 ...do.... 

 Aug. 26 

 Aug. 28 

 Aug. 26 

 ...do.... 

 Aug. 28 

 Aug. 27 

 Aug. 24 

 Aug. 28 

 Aug. 27 

 Aug. 26 

 Aug. 27 

 Aug. 28 

 Aug. 27 

 Aug. 28 

 Aug. 27 

 Aug. 28 

 Aug. 27 

 ...do.... 

 Aug. 28 

 Aug. 31 



Days. 



