Further species, analogous in habit to Leptus autumnalis, are described by Riley from Central and South America as L. americanus and L. irritans.
[L. autumnalis attacks small mammals by preference, such as moles and hares, which are often literally covered with them. Dogs are also subject to their attack, and cats suffer similarly. This mite also frequently appears in colonies on cows; cavalry horses after autumn manœuvres often suffer from an erythematous affection about the hocks and knees due to this pest.
[A number of Leptus, so far undescribed, occur abroad which attack man in the same way as L. autumnalis in Europe. Dr. Durham has brought me specimens from British Guiana called bête rouge; this species works under the skin much as does our European species, but it is very distinct, being considerably larger.—F. V. T.]
Trombidium tlalsahuate, Lemaire, 1867.
T. tlalsahuate occurs in Mexico under conditions similar to those of Leptus here. It also frequently attacks men, and especially fastens itself on to the eyelids, in the axillae, navel, or on the prepuce; it induces itching and swelling of the parts affected, and sometimes even causes suppuration; the symptoms, however, generally disappear after a week and remain localized.[333]
Other species of mites which attack man are reported, mostly by travellers, from various other places; zoologically, however, there is little known about them. The pou d’agouti in Guiana, niaibi in New Granada, colorada in Cuba, mouqui in Para, and the buschmucker in New Guinea represent a few of these.
Akamushi or Kedani.
In a few districts of Japan there occurs a serious illness, with a mortality of 40 to 70 per cent. It is called river or flood fever, and the Japanese doctors have connected it with a small mite (akamushi, kedani). Baelz has opposed this opinion on the grounds that he has repeatedly observed the same species of mite in his dwelling without any subsequent illness occurring. According to Keïsuke Tanaka, however, a connection certainly does exist, inasmuch as the akamushi, like Leptus, attacks persons to suck blood. If the mite is not removed, or if the spot attacked is injured by scratching, etc., a papule surrounded by a red area forms, and a pustule ensues; and finally a black scab covers the seat of injury. The lesion becomes the point of entrance of bacteria, especially a species of proteus which produces river fever. If the mites are carefully removed no general illness takes place.