Notes on the ecology of chiggers (Acarina: Trombiculidae) from northern Michigan and the description of a new species of Euschoengastia

Abstract

Information is presented concerning host-parasite relationships and ecological preferences of 11 species of larval chiggers from northern Michigan. Euschoengastia michiganensis, new species, is described, type host, Microtus pennsylvanicus, type locality, 6.1 mi. W Pellston, Emmet Co., Michigan. Larval trombiculids previously reported from Michigan include Neotrombicula bisignata (Ewing) (Brennan and Wharton, 1950); Miyatrombicula esoensis (Sasa and Ogata) and N. waynensis (Brennan and Wharton) (Brennan and Jones, 1950); Leptotrombidium myotis (Ewing), N. harperi (Ewing), N. microti (Ewing), N. waynensis, Miyatrombicula sp., Euschoengastia blarinae (Ewing) and E. set osa (Ewing) (Lawrence et al., 1965), and M. esoensis, E. blarinae and E. crateris Farrell (Johnston and DeGiusti, 1961). Thus, only nine species in four genera are known from Michigan. This paper reports 11 species in six genera of chiggers collected in the Douglas Lake region of northern Michigan (Emmet, Cheboygan and Mackinac Counties) during the summers of 1965 through 1968; two species are new. One described below is phenetically similar to Euschoengastia blarinae and the other is similar to Leptotrombidium myotis and will be described as new in a revision of North American Leptotrombidium by J. L. Lucas and R. B. Loomis. New state records include Eutrombicula splendens (Ewing), Fonsecia gurneyi (Ewing) and Euschoengastia peromysci (Ewing). Information presented will substantiate, and in some cases add to, the knowledge concerning distributions and ecological preferences of these 11 species. Methods and Materials Approximately 6790 trap nights were spent trapping small mammals during the tenure of this study, and other vertebrates that could be obtained (road kills) were saved and inspected. These efforts produced 807 vertebrates of 71 species which were examined for larval chiggers and other ectoparasites. The vertebrates included 84 amphibians of six species (no chiggers), 59 snakes of seven species (two host species, 1 Received for publication May 18, 1973. 2 Department of Biology, University of North Dakota, Grand Forks, North Dakota 58201 This content downloaded from 157.55.39.139 on Sat, 26 Nov 2016 04:07:39 UTC All use subject to http://about.jstor.org/terms 228 Journal of the Kansas Entomological Society Table 1. Classified list of positive hosts and chiggers recovered in the Douglas Lake area during the summers of 1965 through 1968.