ENTOMOLOGY

404 SANITARY ENTOMOLOGYin man and animals. The BICHO-COLORADO ITCH is caused by themite Tctranychus molcstissimus Weyenbergh, which thrusts its hypostomainto the skin of man and animals in Argentine and Uruguay. InEurope a similar dermatosis is- caused by the related species T. tclariusLinnaeus, variety russcolus Koch. These two species belong to the familyTetranychidae.The disease known as "GONONE" in Celebes and New Guinea iscaused by the-Trombidian mites j1{icrotrombid~u.m wichmanni Oudemansand Schongastia 'Vandersandei Oudemans. This attack occurs both onman and animals. In Europe and America' attack by various alliedspecies is very common.' The ordinary name for the attack is REDBUGS or CHIGGERS. The principal species which have been describedas causing this attack are j1{icrotrombidium tlalsahuate Lamaire in •Mexico; Trombidium holoBericewm Linnaeus, T. inopinatum Oudemans,and T. aut'lllTTllTlalia Shaw in Europe; T. batatas Linnaeus in the WestIndies; Lcptus americanus Riley, and L. iritans Riley in North America;and also Trombidium striaticcps H. & 0., j1{ ctatrombidium lJOriccps H.& 0., j1{icrotrombidi'lllm pusillwm Hermann, and Allotrombidium fuliginosumHermann. The attack of chiggers is very painful and also difficultto relieve. Dusting of flowers of sulphur in the clothes is a good preventive.I have had fairly good success in taking a hot bath immediatelyafter coming from the field and then rubbing in ammonia.The allied species Leptus akamushi Brumpt not only causes adermatosis, but also a definite disease which will be treated in a laterparagraph. This is a Japanese species.A troublesome acarine dermatosis, which frequently causes swellingwhich may be dangerous, is caused by Holotltyrus coccinella Gervais IIIMauritius, which normally attacks dogs and geese, but also attackschildren.In the family Parasitidae quite a number of species are charged withcausing dermatosis. Dermanyssus gallinac Rcdi and D. hirwndinis Hermann,common avian parasites may also cause dermatosis in man. D.gallinac sometimes causes papular eczematous derm-atosis. Liponyssusbacoti Hirst, a rat parasite in Australia, Africa and South ,America,occasionally causes dermatosis of people working in stores and granaries.URTICARIASIS is caused by various species of the family Tarsonemidae.The mite, Pediculoides 'Ventricosus Newport, causes a diseaseknown under a number of different names, as GRAIN ITCH or ERY­THEMA URTICARIA. This mite becomes globular and reproducesits young at a very rapid rate. It burrows under the skin and is verypainful. Many -workers in harvest fields are attacked by this mite, especiallyin Europe. It occurs quite commonly in America. A similar dermatosisis caused by TarS01l1nnus wncioot!U, T. intcctus, and Crithoptes