(1) The chiggers of the other species tested were found negative.
(2) Over 60 forms of parasites were found out as follows: three species of blood parasites, 12 species of Coccidia, 8 species of cestodes, 12 species of nematodes, one species of Acanthocephalus, three species of chigger mites, 15 species of gamasid mites, 6 species of ixodid ticks, fleas and lice.
(3) Chiggers were absent on Mus platythrix from a habitat about 40 meters away from the B. bengalensis and S. murinus collection sites.
(4) The 12 additional arthropod species recorded from the woodland mice consisted of 1 nidicolous beetle, Leptinus orientamericanus; 1 bot, Cuterebra fontinella; 3 fleas, Ctenophthalmus pseudagyrtes, Orchopeas leucopus and Peromyscopsylla scotti; 1 tick, Dermacentor variabilis; 2 mesostigmatid mites, Androlaelaps fahrenholzi and Ornithonyssus bacoti; 3 chiggers, Comatacarus americanus, Euschoengastia peromysci, and Leptotrombidium peromysci; and 1 undescribed pygmephorid mite of the genus Pygmephorus.
(5) R. argentiventer was host to significantly greater numbers of chiggers per rat than was R. tiomanicus.
(6) R. tsutsugamushi was isolated from chigger mites of an L. pallidum-rich group, displaying the highest titer to Karp strain.
(7) A diffuse inflammatory response occurred at the site of chigger and tick attachment which consisted of histiocyte, heterophil, fibroblast and lymphocyte infiltration that often extended into the dermis.
(8) Eleven species were identified: one flea (Orchopeas howardi (Baker], three suckling lice (Enderleinellus longiceps Kellogg & Ferris, Hoplopleura sciuricola Ferris, and Neohaematopinus sciuri Jancke), one tick (Dermacentor variabilis Say), two mesostigmatid (gamasid) mites (Androlaelaps casalis (Berlese) and A. fahrenholzi (Berlese], and four chiggers (Eutrombicula alfreddugesi (Oudemans), E. splendens (Ewing), Leptotrombidium peromysci Vercammen-Grandjean & Langston, and Parasecia gurneyi (Ewing].
(9) Chigger mites of the genus Leptotrombidium (Acari: Trombiculidae) transmit scrub typhus, caused by Rickettsia tsutsugamushi (= R.orientalis) in South-East Asia.
(10) The chicken is available as a bait animal for the study of vector mites and has been found to be infected by chigger mite bite in an area endemic of scrub typhus.
(11) An initial exposure did not elicit macroscopic changes at chigger attachment sites, while all third and fourth exposure animals had marked reactions consisting of erythema, epidermal thickening and serous exudation.
(12) New species of chiggers from Tadzhikistan are described: Leptotrombidium tamanta sp.
(13) There was an increased inflammatory response in older lizards that may have been an augmented host sensitivity following repeated exposure to chiggers.
(14) Chigger infestation may be minimized by the use of proper clothing and insect repellents.
(15) Considering the vector load and numbers of chiggers being returned to the ground by a given host, a rate of 0.5% appeared adequate to account for the prevalence rate of R. tsutsugamushi observed in the 2 host species.
(16) Histopathological effects of the chigger, Eutrombicula lipovskyana, on the mite pockets of neonatal, juvenile and adult Yarrow's spiny lizard, Sceloporus jarrovii, were investigated.
(17) Chigger infestations are caused by mite larvae that feed on the host's epidermal cells.
(18) Intense pruritus is the usual response, but more severe reactions and chigger-borne disease may also occur.
(19) The direct fluorescent antibody technique for assaying infections in chiggers proved more sensitive than mouse inoculation.
(20) Synotpic keys to the 87 genera of chiggers in the Western Hemisphere (Nearctic and Neotropical regions) as well as illustrations to the terminology employed, are presented.