1910] California Rodent Fleas 81 



SUMMARY OF RESULTS. 



I. The breeding of fleas under laboratory conditions can be 

 carried on quite satisfactorily when there is furnished a medium 

 simulating the nest of the host. It will be seen that fleas taken 

 from the natural host can be kept alive without food for a con- 

 siderable time, providing the proper moisture conditions are 

 maintained. A medium of moist sawdust with a few grains of 

 wheat prolonged the life of these insects to twenty- six days. 

 Those without this medium under the same conditions, died on 

 the seventh day. 



2. Rat fleas namely, L. cheopis, C. fasciatus can not jump 

 higher than 3 1-8 inches. 



P. irritans, the human flea, was found to make a perpendicular 

 jump of 7 3-4 inches and as far as 13 inches on a horizontal 

 plane. 



3. Experiments with black and white guinea pigs show that 

 in relation to color attraction white animals are no more attractive 

 to the fleas than are the dark colored ones. 



4. Experiments with adhesive paper baited with meat, 

 demonstrate that fleas can not be trapped by the odor of meat. 



5 . In the mating of fleas, the female takes the initiative and 

 the male assumes the passive role. 



6. Fleas reared from the cocoon kept without a host have 

 never been observed to copulate or oviposit. 



7. The eggs are never laid on the host. Oviposition takes 

 place within thirty- six hours after the female is removed from the 

 host. 



8. The process of hatching consumes a period of 3-4 days. 

 The embryo breaks through the shell by means of a special egg 

 pick, which is instrumental in the emergence. 



9. The larvae can live on the bloody egg pellicles and the 

 dejecta of the parent for a period of 5-6 days. 



10. The larvae are positively heliotropic in the early stages 

 and repelled by light in the later stages. 



11. Adult fleas are negatively phototaxic. 



12. The California rodent fleas have a greater life in all 

 stages than fleas of the Eastern United States and India. The 



