High prevalence and intensity of infestation of Eutrombicula alfreddugesi (Acarina: Trombiculidae) on Tropidurus torquatus (Squamata, Tropiduridae): effects of body size and on body condition across ten populations along the Brazilian coast

Abstract

We investigated the infestation of Eutrombicula alfreddugesi mites on Tropidurus torquatus lizards across ten coastal populations in Brazil to evaluate variations among localities and relationships with intrinsic features of hosts (body size and body condition). For each population, we calculated the prevalence of infestation and the mean number of mites per host (mean intensity of infestation). Lizards from all populations were infested by mites, with prevalence ranging from 95.6 to 100%. Mean intensities of infestation also were always high, ranging from 55.3 ± 88.8 to 280.9 ± 208.2 mites per lizard. The lizard body regions most intensely used as microhabitat by mites were the axillae and neck (which bear "mite pockets" in T. torquatus). In most populations, the number of mites tended to increase with the body size of hosts. The body condition of hosts and the intensity of infestation were positively correlated, considering the total sample (i.e. lizards of all populations pooled). The main microhabitats (i.e., body regions) used by E. alfreddugesi on T. torquatus represented total intensities of infestation, suggesting that counting mites on these body regions provide a useful index to estimate the overall intensity of infestation. Lizards are suitable and predictable resources for parasitic mites, which take advantage of ecological and morphological features of host individuals and species, with large body sizes, imbricated and keeled scales, and presence of skin folds and mite pockets favoring occupation and high intensities of infestation by mites.

Co-occurrence of Eutrombicula alfreddugesi and Oswaldofilaria chabaudi in Tropidurus torquatus and first report of microfilariae in the chigger mite: possible evidence of a lifecycle pathway?

“…Larger lizards (snout-vent length (SVL) = 81.4 ± 12.3 mm) were purposely chosen because a positive correlation between host body size of and intensity of infection by O. chabaudi is expected (see Pereira et al, 2012); this maximizes the probability that the mite and the nematode will co-occur. Likewise, the number of mites tends to increase with the body size of lizards due the wider body surfaces available to infestation (Rocha et al, 2020). The present results confirmed this premise, in which SVL was positively and strongly correlated with mite intensity of infestation (P < 0.001; r s = 0.82), similar to previous findings (Carvalho et al, 2006;Rocha et al, 2008Rocha et al, , 2020.…”

“…Despite the low host specificity exhibited by E. alfreddugesi, the lizard T. torquatus is one of its more common hosts. This host-parasite association has been widely reported in Brazil in which the mite shows medium to high infestation rates (see Carvalho et al, 2006;Rocha et al, 2008Rocha et al, , 2020. The biological relationship between T. torquatus and E. alfreddugesi suggests that it is old, since lizards developed skin folds (mite pockets) that favour the aggregation of this ectoparasite (Frost et al, 2001).…”

“…chabaudi is expected (see Pereira et al ., 2012); this maximizes the probability that the mite and the nematode will co-occur. Likewise, the number of mites tends to increase with the body size of lizards due the wider body surfaces available to infestation (Rocha et al ., 2020). The present results confirmed this premise, in which SVL was positively and strongly correlated with mite intensity of infestation ( P < 0.001; r s = 0.82), similar to previous findings (Carvalho et al ., 2006; Rocha et al ., 2008, 2020).…”

“…torquatus is one of its more common hosts. This host–parasite association has been widely reported in Brazil in which the mite shows medium to high infestation rates (see Carvalho et al ., 2006; Rocha et al ., 2008, 2020). The biological relationship between T .…”

A new case of trombiculiasis caused by Eutrombicula daemoni Bassini-Silva & Jacinavicius, 2018 (Trombidiformes: Trombiculidae) in a dog from Brazil

“…The fauna of chiggers was poorly represented in the Espírito Santo State, there are only two records. One of these records is the rare association with a chigger, Odontacarus sp., parasitizing an adult male of a whip spider, Charinus brasilianus Weygoldt, 1972 (Charinidae: Amblypygi) in Santa Teresa municipality (Gonçalves-Souza et al 2014); the other record is the occurrence of Eutrombicula alfreddugesi s. l. on Tropidurus torquatus (Wied, 1820) (Squamata: Tropiduridae) in the São Mateus, Guarapari and Presidente Kennedy municipalities (Rocha et al 2020).…”