Three New Species of Chiggers (Acari: Trombiculidae) from Brazil1

Abstract

Microtrombicula rhipidomysi from Rhipidomys masti-calis, Colicus brasilieiisis from Oryzomysfornesi and Oryzomys subfla-vus, and Kymocta lutui from Zygodontomys lasiurus lasiurus are described as new from specimens collected in Brazil. Examination of ectoparasites of small mammals collected by one of us (JMD) in Brazil has revealed 3 new species of chiggers, which are described and illustrated here. Holotypes are in the B.P. Bishop Museum (BPBM) and paratypes in the U.S. National Museum of Natural History/Smithsonian Institution (chigger collection currently housed-lumbus. Terminology for descriptions follows Goff et al. (1982). All measurements are given in micro-metres. Small mammals were collected in wooden-based rat traps located in 3 major habitats in the Serra da Canastra National Park, Minas Gerais State, Brazil. Ectoparasites were located and removed from trapped mammals with the aid of a dissecting microscope and stored in 70% ethyl alcohol. Host mammals are held in The Museum, Michigan State University. Microtrombicula rhipidomysi Goff, Whitaker & Dietz, new species FIG. 1 Description of species. Larva. Idiosoma. Measuring 285 x 190 in engorged specimen. Eyes 2/2, anterior larger, ocular plate absent. 1 pair of humeral setae, measuring 31-36; 26 dorsal idio-somal setae, measuring 25-27, arranged 6-6-6-4-4; 2 pairs of sternal setae, anterior 23-25, posterior 23-24; 16 preanal setae, 19-23; 12-14 postanal setae, 21-23; total idiosomal setae 60-62. Gnathosoma. Palpal setal formula B/B/fff/6B & f; palpal claw 2-pronged, axial prong internal; cheliceral blade (24-25) with tricuspid cap; galeala N; gnathobase lightly punctate, bearing a pair of branched setae. Scutum. Lightly punctate with bicon-cave anterior margin; posterior margin rounded posterior to PL bases; AM base slightly anterior to. level of AL bases; SB anterior to level of PL bases; PL > AM > AL; PW/SD = 1.15-1.30; sensillae slightly expanded, with branches on distal %, nude basally. Scutal measurements of holotype followed by means and ranges of type series in parentheses: AW 49 (45, 43-49); PW 53 (54, 52-59); SB 17 (17, 16-18); ASB 20 (20, 17-21); PSB 26 (24, 22-26); AP 22 (22, 20-23); AM 24 (24, 23-25); AL 24 (22, 19-24); PL 29 (29, 28-30); sens. 40 x 3 (41 x 2, 40-43 X 2-3). Legs. All 7-segmented, terminating in a pair of claws and a clawlike empodium. Onychotriches absent. IP 519-537. Legl. 183-192; coxa with 1 branched seta (IB); trochanter IB; basifemur IB; telofemur 5B; genu 4B, 3 genualae ( ), microtibiala (It); tarsus (42 x 17) 21B, tarsala (o>) (11-12), microtarsala (e), subtermin-ala (£), parasubterminala, pretarsala (£). Leg II. 155-161; coxa IB; trochanter IB; basifemur 2B; telofemur 4B; genu 3B, gen-uala (CT); tibia 6B, 2 tibialae (); tarsus (35 x 16) 16B, tarsala (