Species composition of mites (Acari: Trombiculidae, Dermanyssidae, Laelapidae) on pest rodents and shrews in Madurai, India

Trombiculid chigger mites were collected from pest rodents and shrews. This study was carried out in different habitats like urban, semi-urban, and rural sites in Madurai district, South Tamil Nadu, India during 2017-2018. A total of 3219 chigger mites comprising 12 different species under three families (Trombiculidae, Dermanyssidae and Laelapidae) and one sub order (Oribatida) were collected from 151 rodents and shrews, belonging to six different species in this study. The chigger infestation rate in these small mammals was 56.47. The following chigger mites and adult mite species were identified from the Madurai district:  Leptotrombidium deliense, L. keukenschrijveri, L. indicum, L. rajesthanense, Schoengastiella ligula, Microtrombicula sp., Neotrombicula microti, Trombicula hypodermata, Schoengastia species (Chigger mites); Dermanyssus gallinae, Laelaps echidninus, Liponyssoides sanguineus and Oribatida (Adult mites). The predominant species recorded from these areas are L. deliense (65.94%), L. indicum (11.50) and S. ligula (15.27). Even though maximum chigger mites infestation rate was recorded in rodents and shrews from urban areas (65.5), followed by semi-urban (53.5) and rural (54.5) areas. Trap positivity rate (18.1%), rodents/shrew captures (5.42±2.97) and chigger collection (118.08±188.9) were observed significantly (P <0.05) more in rural clusters compared with urban clusters. This study showed the predominant trombiculid mites activity on small mammals of this place which can forewarn the public health officials to understand the ground-level situation to take up necessary control measures for the prevention of mite borne diseases.