Explorational analysis of the abundance and prevalence of chigger and gamasid mites parasitic on small mammals in Vietnam.

We studied chigger and gamasid mite loads on small mammals during the dry season in Vietnam and used both our field data and museum collections to estimate the influence of environmental factors on mite abundance and prevalence. Generalized linear (mixed effect) models were used to analyze the data. We examined 1,239 small mammal individuals, which were obtained from field expeditions and museum collections belonging to 59 species. In different localities, Rattus Fischer (Rodentia: Muridae), Niviventer Marshall (Rodentia: Muridae), and Maxomys Sody (Rodentia: Muridae) were the most common animals captured. The prevalence of chigger and gamasid mites in our expedition data was high: 72% and 62%, respectively. We found differences in the abundance of chigger mites between different populations of the same species of small mammals. Season and locality were the main factors that influenced chigger mite abundance and prevalence. The best model that predicted the abundance and prevalence of chigger mites included geography (province) as a predictor and host species and season as random effects. For the first time, we analyzed factors connected with climate and weather affecting chigger mites of small mammals in Vietnam.

New species and new records of chigger mites (Acariformes, Trombiculidae) from Cambodia.

Two new chigger species, Leptotrombidium mondulkiri sp. nov. and Walchia keoseima sp. nov., and one new subspecies, Leptotrombidium pilosum cambodiensis subsp. nov., are described from Cambodia. Three species, Walchia lupella (Traub and Evans, 1957), W. micropelta (Traub and Evans, 1957), and W. kritochaeta (Traub and Evans, 1957), are for the first time reported from the country. A redescription of W. lupella is given based on new materials from Cambodia and Thailand.

Bat ectoparasites: chigger mites (Trombiculidae), ticks (Ixodidae and Argasidae), and bugs (Cimicidae) in the Eastern Palaearctic.

Nine species-level taxa of bat ectoparasites, three chigger mites (Trombiculidae), three hard (Ixodidae), and one soft tick (Argasidae) species, as well as two bug (Cimicidae) species from nine bat species hosts were detected in the Eastern Palaearctic. Trombiculid larvae of Leptotrombidium schlugerae, Leptotrombidium album, and Ascoschoengastia latyshevi were first recorded on bats in the temperate zone of eastern Russia. L. schlugerae was more abundant than A. latyshevi in the same study sites in Eastern Siberia, and the main hosts of both chigger species were Plecotus ognevi and Eptesicus nilssonii. Ixodid ticks Dermacentor marginatus, Ixodes simplex, and Ixodes sp. were sampled from bats in Kazakhstan, the Far East, and Eastern Siberia, respectively. Phylogenetic analysis based on Cox1, 16S rDNA, and ITS2 sequences of I. simplex showed that the specimens from the Far East grouped into a clade distributed in the Eastern Palaearctic and India. In turn, the specimen of Ixodes sp. from Eastern Siberia was most closely related to Ixodes soricis and Ixodes angustus with p-distance of 9.8-10.7% (Cox1), suggesting that this tick probably belongs to a new species. Argas vespertilionis larvae were collected from three widespread bat species in Kazakhstan. Two bug species, Cimex pipistrelli and Cimex aff. lectularius, were recorded in the Far East and Eastern Siberia, respectively. Specimens from Transbaikalia were morphologically identified as Cimex lectularius. However, they differed from the latter by 12.5-12.9% of Cox1 sequences, indicating that C. aff. lectularius may be a new species.

Re-descriptions of eight chigger mite species (Acariformes: Trombiculidae) of the Leptotrombidium generic complex from Vietnam.

Six mite species of the genus Leptotrombidium Nagayo, Miyagawa, Mitamura and Imamura, 1916 and one species from each of the genera Lorillatum Nadchatram, 1963 and Trombiculindus Radford, 1948, incompletely described by Schluger et al. (1960b, 1963) from rodents and tree shrews in North Vietnam, are re-described based on type series. Lectotypes and paralectotypes have been designated for all redescribed species. Two new synonyms have been established: Leptotrombidium magnum (Schluger, 1960) (= Leptotrombidium dooleyi Nadchatram, 1970, syn. nov.; = Leptotrombidium submagnum Wang, Li and Shi, 1988, syn. nov.).

Redescriptions of ten chigger mite species (Acariformes: Trombiculidae) from Vietnam.

Ten species of chigger mites from the genera Gahrliepia Oudemans, 1912, Walchia Ewing, 1931, Cheladonta Lipovsky, Crossley and Loomis, 1955, Doloisia Oudemans, 1910, Schoutedenichia Jadin and Vercammen-Grandjean, 1954, and Microtrombicula Ewing, 1950, incompletely described by Schluger et al. (1960a, c, 1961, 1963) from rodents in North Vietnam, are redescribed based on type series. Lectotypes and paralectotypes have been designated for all species. A new synonymy has been established: Walchia delicatula (Schluger, Grochovskaja, Ngu, Hoe and Tung, 1960) (= Walchia tianguangshanensis Zhao, 1981 syn. nov.).