Taxonomy, life cycles and the origin of parasitism in trombiculid mites

The effects of mite parasitism on the reproduction and survival of the Taiwan field mice (Apodemus semotus)

“…Furthermore, we did not find sex-biased parasitism in either breeding or non-breeding season. This is one of the few empirical studies on host-parasite ecology from a relatively under-studied geographic region (Southeast Asia), where warm and wet climates year-round may allow ectoparasites with free-living stages to breed more frequently and persist at high densities (Takahashi et al 1993;Waller 1997;Shatrov and Kudryashova 2006). Sex-biased parasitism is a complex phenomenon that can be influenced by the biology of particular host and parasite species, mediated by environmental factors, and exhibited spatial and temporal variation (reviewed by Krasnov et al 2012).…”

“…Although ectoparasites tend to show male-biased parasitism and references therein), several ecological characteristics of Trombiculid mites and A. semotus may help explain the lack of sex-biased parasitism in this study. Trombiculid mites only remain attached to a host individual for a short period of time (several days to a few weeks; Wharton and Fuller 1952;Baker et al 1956), and they appear to be tightly associated with particular habitats in which they are able to infect a wide range of host species (Shatrov and Kudryashova 2006), suggesting this parasite may not be choosy about host individuals. A recent study on Trombiculid mites (Leptotrombidium imphalum) in lowland Taiwan suggests that they are not able to freely distribute themselves according to the quality of host individuals, presumably due to their limited mobility (Kuo et al 2011).…”

“…Trombiculid larvae (chiggers) attach to a host where the skin is thin for feeding, which usually lasts several days to a few weeks (Wharton and Fuller 1952;Baker et al 1956). Free-living stage of Trombiculid mites are soil dwellers with complex life cycles (reviewed by Shatrov and Kudryashova 2006). Although seasonal patterns of mite development are still unclear, available reports suggest that these mites could retard their development at any stage in the cold period (e.g.…”

“…In the tropics, these mites may continue their development without any conspicuous diapause and have a much shortened life cycle (reviewed by Shatrov and Kudryashova 2006). For example, under laboratory conditions (i.e., 27°C and relatively humidity of 85%), the entire life cycle of Trombiculid mites can be completed in 2 to 3 months (Traub and Wisseman 1968), as appose to 150 to 400 days among boreal species (Shatrov and Kudryashova 2006). Therefore, seasonality in their larval emergence and abundance is likely influenced by the climate of the study system.…”

Dermatitis pruriginosa tras paseo por la montaña

“…Una vez repleta, se suelta del hospedador y continúa el ciclo en el suelo, mudando a ninfa (4 pares de patas), y esta a adulto. Cuando se dan las condiciones apropiadas las hembras depositan los huevos sobre la tierra, comenzando así el siguiente ciclo, que se completa en un año4 .La dermatitis resulta de la combinación de las enzimas digestivas secretadas por el ácaro y la respuesta inmunitaria del paciente. Esta respuesta parece estar determinada por el efecto irritante de la saliva de los ácaros y una hipersensibilidad adquirida a antígenos salivares 3 .…”