n. A very curious insect of the order Aphaniptera, or fleas, and family Pulicidæ, Pulex or sarcopsylla penetrans, closely resembling the common flea, but of more minute size, found in the West Indies and South America.n. A larval harvest-mite, as the so-called Leptus irritans. Same as red-bug and jigger, 2.