Origin:
It is possible this flea originated in eastern Asia in association with Norway and Roof rats.
Biology:
This flea species is the one most notorious for spreading Bubonic Plague, as it has a tendency to become infected with the pathogen. While feeding on an infected host animal the plague bacteria are ingested, but these bacteria may form a blockage in the foregut of the flea, preventing it from swallowing additional blood. In an effort to clear this blockage the adult flea regurgitates as it attempts to feed, potentially pushing the bacteria into the new host animal. The worse the blockage gets the more it attempts to feed, accelerating the transmitting of the disease to many hosts. The life cycle is, otherwise, similar to most fleas. Eggs are deposited on the host animals, which includes rodents most often, and the eggs fall to the substrate and the larvae feed on organic materials there.
Identification:
All fleas are similar in appearance, as wingless insects with bodies flattened from side to side and with long hind legs for jumping. They are black to reddish black in color and have spiny legs as well as rows of spines along other body areas called “combs”. These combs are important for identification of the species. The genal comb is a row below the head and the pronotal comb is a row behind the head. The Oriental Rat Flea lacks both of these combs, helping to separate it from the Cat and Dog fleas as well as other species. It has a stout bristle that originates from in front of the eye, compared with the similar Human Flea where that bristle originates below the eye. Flea larvae are rarely seen, but they are legless and whitish with a brown head, unless they have fed on fecal matter from the adults, in which case they assume a reddish color. They are covered with short hairs, and when disturbed are able to flip about violently in order to escape.
Characteristicts Important to Control:
Since this species most often infests wild rodents and peridomestic rodents such as Norway and Roof rats, eliminating these host animals is necessary. Ground squirrels also are common hosts for this flea and in the western U.S. are considered to be a primary reservoir for bubonic plague. Where permitted, fumigation of rodent burrows with aluminum phosphide will kill the host animals as well as all parasites in the burrow. Dusting of burrows with a contact insecticide can also be effective.
