99 



in less than twenty-four hours. Experiments a little later gave the 

 following* periods: 



Aug. 21. Eggs deposited in confinement placed at 7 p. m. on cow duug free from 

 eggs of other flies. 



23. Larva? one-fourth grown. 

 25. Larva? one-half inch long. 



27. Larva? leaving manure and entering sand to pupate. 

 Sept. 5. Three flies issued. 



Aug. 23. Eggs placed with isolated dung at 1.30 p.m. 



24. (9 a.m.) Eggs have hatched. 



25. Larvse one- fourth inch long. 



29. Apparently full grown. 



30. Puparia found. 

 Sept. 5. Two flies issued. 



6. Four flies issued. 



1. Eggs deposited 10.25 a m. 



2. Eggs were hatched when examined at 9 a. m. 

 5. Larva? half grown. 



7. Larvge entering sand. 



8. Five puparia taken from sand. 



9. All in puparia. 



15. Three adults. \ 



16. Twenty adults. > All found at 9 a. m. 



17. Twenty-six adults. > 



17. Twenty adults, issued hetweeu 12 and 4 p. m. 



From these records it will be seen that from ten to seventeen days, 

 say two weeks, is about the average time from the laying of the egg to 

 the appearance of the flies, and with four active breeding months, from 

 May 15 to September 15, there will be eight generations. The flies will 

 undoubtedly breed later than September 15, but we may allow this time 

 to make up for the time occupied in the development of the eggs in the 

 abdomen of the female. With seven or eight annual generations the 

 numbers of the flies are not surprising. 



Fig. 13.— Hematoma sekkata: a, head of female, front view; &, head of male, front view ; c, head 

 from side— all enlarged. (Original.) 



The adult — Its Habits. — The flies were observed in the greatest 

 abundance during July. They make their first noticeable appearance 



