Amblyomma pseudoconcolor Aragão, 1908

Ezquiaga, María Cecilia & Soibelzon, Esteban, 2021, New records of fleas and ticks in armadillos (Xenarthra: Chlamyphoridae) from the Espinal and Monte ecoregions of La Pampa province, Argentina, Zootaxa 4950 (3), pp. 595-600 : 598-599

Amblyomma pseudoconcolor Aragão, 1908

( Fig. 2d )

Specimens examined. 3 females on 3 individuals of C. villosus and 3 on an individual of Z. pichiy ; 9 males on 3 individuals of C. villosus and 1 on an individual of Z. pichiy .

Parasitological índices. Total: P=40%; MA=1.1; MI=2.6; Ecoregion Espinal: P=22%; MA=0.2; MI=1; Ecoregion Monte: P=66%; MA=2.3; MI=3.5. Chaetophractus villosus : P=36%; MA=0.7; MI=2; Zaedyus pichiy : P=50%; MA=2; MI=4

No significant differences were observed in the prevalence, mean abundance or mean intensity of A. pseudoconcolor between C. villosus and Z. pichiy (Fisher’s exact test two-sided p -value=1.000; Bootstrap p -value (two-sided) =0.5210; Wilcoxon-Mann-Whitney p -value (two-tailed) = 0.8057, Bootstrap p -value (two-sided) = 0.5180). There were also no significant differences in prevalence, mean abundance or mean intensity of A. pseudoconcolor when Espinal and Monte were compared (Fisher’s exact test two-sided p -value= 0.136; Bootstrap p -value (two-sided) = 0.1520; Wilcoxon-Mann-Whitney p -value (two-tailed) = 0.2188, Bootstrap p -value (two-sided) = 0.2370 respectively).

Type host and locality. Dasypus sp., Brasil .

Geographic range. Argentina (provinces of Buenos Aires, Catamarca, Chubut, Córdoba, Formosa, Salta and Santiago del Estero), Bolivia, Brazil, French Guiana, Paraguay, Surinam and Uruguay.

Remarks. This species is, together with A. auricularium , typical of armadillos but it has been recorded on other hosts such as bovines, canines, mustelids, cervids, marsupials and even humans ( Guglielmone & Nava 2006; Nava et al. 2017). Although both species are similar and have sometimes been misidentified, adults of A. pseudoconcolor differ from A. auricularium by having an ornate scutum with small and pale spots adjacent to the marginal groove ( Fig. 2d ). The biogeographic distribution of this tick includes the ecoregions of Chaco, Monte, Pampas and Patagonia ( Guglielmone & Nava 2006); therefore, this is the first record for the Espinal and also for the province of La Pampa.

In the present work we documented for the first time the fleas and ticks of two armadillo species present in the province of La Pampa. Species of Malacopsyllidae were the most frequent ectoparasites found. Previous studies have reported that fleas of this family are the most common among armadillos in Argentina ( Mauri & Navone 1993; Ezquiaga & Lareschi 2012). These fleas possess several adaptations to their hosts: strongly sclerotized exoskeleton, a considerable expansion of the abdomen of gravid females, powerful distitarsomeres, and ungues very strongly developed ( Smit 1987). These characteristics are indicative of habits involving a long duration of their stay on the ventral region of the host, which is subjected to brushing against the substrate, and fleas must therefore be able to anchor firmly to the thick hairs of their host ( Smit 1972, 1987). In this work, there were no differences in prevalence and intensity between host species, which confirms that these fleas have no apparent preferences for a particular host species. However, M. grossiventris was the most frequently found flea in both host species.

Phthiropsylla agenoris and H. broscus were not found in Espinal; these fleas seem to prefer more xeric habitats than M. grossiventris , which is more frequently found in mesic environments such as the Pampas region ( Ezquiaga et al. 2020). These authors studied the arthropod parasites of Z. pichiy in the south of Mendoza province, and only detected P. agenoris , attributing the absence of M. grossiventris to a possible influence of the environment. In this regard, Krasnov (2008) suggested that the diversity of flea assemblages is mainly influenced by local factors. In most of the host species analyzed by the author, the diversity of flea assemblages was correlated with one or more climatic variables ( Krasnov 2008).

The finding of A. pseudoconcolor confirms that it is a widely distributed species among armadillos and in different environments. In this regard, Nava et al. (2017) indicated that this tick has a high plasticity to adapt to different environmental conditions, and the distribution of A. pseudoconcolor seems to be determined by the range of hosts rather than environmental conditions, probably due to its nidicolous habits.

The present work exposes the need to continue and expand the fieldwork on the distribution of fleas and ticks and their xenarthan hosts in the province of La Pampa, after decades of neglect. New results will allow us to further characterize not only the mammalian fauna and their parasites in the Espinal and Monte ecoregions, but also to analyze the impact of the advance of the agricultural frontier in the province and propose new conservation areas.

It is important to highlight the use of multiple sources of data provision, since as mentioned above (Materials and Methods), in this study we used both animals trapped (and later released) and specimens found hit by cars on provincial routes, one individual killed by dogs in a private area and one specimen hunted by locals for food purposes. Thus, new localities were established for fleas and ticks that parasitize xenarthrans by recording C. villosus as a new host for H. broscus and Espinal as a new ecoregion for A. pseudoconcolor . These findings highlight the importance of continuing studies on the parasitic diversity of mammals, since it is underestimated in these hosts.

Figures

FIGURE 2. Ectoparasites of armadillos. a) Phthiropsylla agenoris, female. b) Malacopsylla grossiventris, male. c) Hectopsylla broscus, female. d) Amblyomma pseudoconcolor, male.