CHIGGERS — FARRELL 109 



lied the salamanders and Ctdex quinquefasciatus Say. Dr. J. R. 

 Bailey, Duke University, identified the garter snakes and the 

 worm snakes. All other identifications of Duke University host 

 material were made to species only by the author. 



Specimens of the new species described in this paper are 

 deposited in the following collections: U. S. National Museum 

 (USNM) ; Duke University (DU) ; Rocky Mountain Laboratory 

 (RML) ; Carnegie Museum (CM) ; Kansas University (KU) ; 

 South African Museum, Natal (Afr) ; South Australian Museum, 

 Adelaide (Aus) ; and C. E. Farrell personal collection (CEF). 

 The Duke University collection has been placed in the U. S. 

 National Museum. 



Results 



Hosts representing four classes of terrestrial vertebrates were 

 collected in the Duke Forest area during the 28 consecutive 

 months from September 1947 to December 1949 (table 1). Two 

 species of amphibians, seven species of reptiles, 12 species of 

 birds, and 20 species of mammals were included. These hosts 

 were variously parasitized by more than 15 species of chiggers. 

 No Euschongasfia was found on amphibians, reptiles, or birds. 

 Seven species of mammals were parasitized by a total of five 

 species of Euschongastia (table 2) . The mammalian hosts were 

 Blarina brevicauda, Sciurus c. carolinensis, Peromyscus leucopus, 

 Peromyscus n. nuttalli, Pitymys p. pinetonim, Ondatra zibethica, 

 and Sylvilagus floridanus mallurus. The chiggers were E. 

 peromysci, E. rubra, E. bkirinae, E. carolinensis, and E. setosa. 



Species of chiggers did not always occur singly in host collec- 

 tions or on individual hosts. In 37 collections of Peromyscus 

 leucopus four species of Euschmigastia together with two new 

 species of Trombicula and a new genus were found in various 

 combinations (table 3). There v/ere 13 of these combinations of 

 species. E. peromysci was represented in all. The E. peromysci- 

 E. rubra association was most frequent; it was common, also, on 

 individual hosts where the white E. peromysci could be distin- 

 guished easily from the reddish E. tubra. In one collection of 

 BlaHna brevicauda both E. blarinae and the new genus were 

 taken. 



A number of chiggers other than Euschongastia were removed 

 from hosts collected during this study (table 4). These species 

 represented three known genera — Hannemania, Walchiu, and 

 Trombicula — and one new genus. Hannemaniu sp. was found on 



