Pterygosomatidae and Trombiculidae mites infesting Tropidurus hispidus (Spix, 1825) (Tropiduridae) lizards in northeastern Brazil / Ácaros Pterygosomatidae e Trombiculidae infestando lagartos Tropidurus hispidus (Spix, 1825) (Tropiduridae) no nordeste do Brasil

Parasitism of the lizard Tropidurus hispidus by Geckobiella sp. and by larvae of Eutrombicula alfreddugesi was examined in a mountainous area in Chapada do Araripe (07° 16' S and 39° 26' W), southern Ceará State, Brazil. Of the 56 lizards collected (26 females, 27 males, and 3 juveniles), 40 (total prevalence of 71.42 percent) were infested by mites. Mite-pockets were the sites most heavily infested by E. alfreddugesi larvae, while Geckobiella sp. was found uniformly distributed under scales over the host's entire body. The female specimens of T. hispidus parasitised by E. alfreddugesi had an average infestation rate of 8.57 ± 3.62, 1-27, while the males had an average infestation rate of 11.90 ± 2.63, 1-25. The female specimens parasitised by Geckobiella sp. had an average infestation rate of 5.91 ± 2.28, 1-25, while the males had an average infestation rate of 5.43 ± 1.52, 1-23. Seven specimens were also infested by eggs and immature forms of unidentified mites (average 2.28 ± 0.89, 1-7). There were no significant differences between the total prevalence of mites on adult male (70.4 percent) and adult female (65.4 percent) lizards. The body sizes of the hosts did not influence their infestation rates. The average infestation intensity by E. alfreddugesi (10.2 ± 8.7) was significantly greater than the average infestation intensity by Geckobiella sp. (5.9 ± 6.8). T. hispidus is the new host record to Geckobiella mites.

No presente estudo foi analisado o parasitismo do lagarto Tropidurus hispidus pelos ácaros Geckobiella sp. e larvas de Eutrombicula alfreddugesi em uma área na Chapada do Araripe (07° 16' S e 39° 26' W), região sul do Estado do Ceará, Brasil. Dos 56 lagartos coletados (26 fêmeas, 27 machos, e 3 juvenis), 40 (prevalência total de 71,42 por cento) estavam infestados por ácaros. Entre os sites de infestação, as bolsas de ácaros foram os mais infestados pelas larvas de E. alfreddugesi, enquanto Geckobiella sp. foi encontrado distribuído uniformemente sob as escamas por todo o corpo dos hospedeiros. Os espécimes fêmeas de T. hispidus parasitados por E. alfreddugesi tinham uma infestação média de 8,57 ± 3,63, 1-27, enquanto os machos tinham uma média de infestação de 11,90 ± 2,63, 1-25. Os espécimes fêmeas parasitados por Geckobiella sp. tinham uma infestação média de 5,91 ± 2,28, 1-25, enquanto que os machos tinham uma infestação média de 5,43 ± 1,52, 1-23. Sete espécimes estavam também infestados por ovos e formas imaturas de ácaros não identificados (infestação média de 2,28 ± 0,89, 1-7). Não houve diferenças significativas entre a prevalência total de ácaros em machos (70,4 por cento) e fêmeas (65,4 por cento) adultas. As médias dos tamanhos corporais não influenciaram as taxas de infestação. A intensidade de infestação média por E. alfreddugesi (10,2 ± 8,7) foi significativamente maior do que a encontrada para Geckobiella sp. (5,9 ± 6,8). T. hispidus constitui um novo registro de hospedeiro para ácaros do gênero Geckobiella.

Chigger mite infestation of small mammals in a feral biotope of a public park area of south Delhi.

Examination of Bandicota bengalensis (8) and Suncus murinus (4) trapped in a feral biotope of a public park area of south Delhi revealed presence of the known scrub typhus vector Leptotrombidium (L.) deliense, the suspected vector Gahrliepia (S.) ligula and Gahrliepia (Walchia) sp. of chigger mites, on them. The epidemiologically important population indices (chigger infestation rate-CIR and incidence rate--1R) were estimated. The overall CIR of the three mite species on the hosts was 2.83 mite/host, and that of L. deliense on B. bengalensis and S. murinus was 1.62 and 0.25 respectively, whereas that of G. ligula was 0.50 on both the host species. The overall 1R was 66.66 per cent being 62.5 per cent for B. bengalensis and 75.0 per cent for S. murinus. Incidence of L. deliense on B. bengalensis was higher (62.5 per cent) than on S. murinus (25.0 per cent), whereas IR of G. ligula was higher (50.0 per cent) on S. murinus than on B. bengalensis (25.0 per cent). The Chi square test of independence has shown that these chigger species are not host specific, but are rather habitat specific. Chiggers were absent on Mus platythrix from a habitat about 40 meters away from the B. bengalensis and S. murinus collection sites. The high CIR value for scrub typhus vector L. deliense (1.62) warrant investigations on natural infection rates of R. tsutsugamushi in the chiggers and screening of local human population for the infection.

Vectors of scrub typhus and their hosts on a mature oil palm estate.

L. (L.) deliense was the predominant vector of scrub typhus in a mature oil palm estate, but a small number of L. (L.) fletcheri (0.1% from rodents) and L. (L.) vivericola (0.02% from rodents and 8.0% from black plates) was also collected. Although good correlation between L. (L.) deliense collected from rodents and from black plates was not established, either method may serve as a general indicator of population fluctuations over a period of time. For the most part, the vectors of scrub typhus were limited to litter piles, and thus, the possibility of contracting scrub typhus within this type of habitat was minimal.