ENTOMOLOGY

THE LIFE HISTORY AND CONTROL OF FLEAS 365silantiewi Wagner) occurs in numbers on the "tarbagan" or groundhogin Manchuria and was thought to be concerned in the transmission ofplague from that host to man in the recent Manchurian outbreak. However,subsquent investigations apparently failed to substantiate thistheory.The field mouse flea (Ctenophthalmus agyrte8 Heller) occurs in Englandand other parts of Europe. It is common on voles and field miceand also on rats living in the open. It has no inclination to bite man.This species probab~y plays little part in the dissemination of plague,but when the disease gets among wild rodents it no doubt would aidin spreading it from animal to animal.Pygiop8ylla ahalae Rothschild has been shown capable of carryingplague. It is an East Indian Island species and according to De RaadtFIG. 69.-'I'he sticktight flea, Echidnophaga galli7lacea: Adult femole. Greatly enlarged.(Bishopp.) From U. S. Dept. Agr. Bull. 248, figs. 2, ~.it is .abundant on rats in coffee plantations in Java, but rare on rodentsin buildings. He avers that the species of fleas found on rats may beused as an index to the source of the rat population of a given place.The squirrel ~as (CeratophyUu8 acu,tus Baker and Hoplop8yUu8anomalu8 Baker) are abundant in the western United States on groundsquirrels. They have been shown capable of transmitting plague, andboth feed readily on man and will feed on rats.The sticktight flea (Echidnophaga gallinace'Us Westwood) (figs. 69 170) is an important pest of poultry in the southern United States. Thisspecies is widely distributed in the subtropical and tropical parts of theworld. It atttacks several wild b1'rds in addition to domestic species andhas been taken on rats in numbers. It bites man with avidity.The chigoe or penetrating flea (Dermatophuu.s penetrans Linnaeus)is troublesome in the West Indies, Mexico, and northern South America,and has been introduced into West Africa and from there to India.It burrows into the skin of the feet, especially around the toenails. Many