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This research evaluates the behavior of plaster with a water-repellent additive when submitted to a natural aging process. Casting plaster and silane/siloxane-based water-repellent were used as materials. The water/plaster ratio was set at 0.7 and the contents of 0.2% and 0.4% of water-repellent were used, in relation to the plaster mass. Plaster pastes without water-repellent (reference) and containing mass water-repellent were evaluated at ‘zero’ age and after 30, 60, 90, 120, and 150 days of natural aging. After 150 days of natural aging, it was observed that the mechanical properties of the material (compressive strength and hardness) did not undergo significant variations and remained above the minimum required by a standard. The addition of water-repellent resulted in a considerable reduction in water absorption, demonstrating the water repellency capacity of the material, compared to the reference specimen.

The leiuperid genus Pleurodema (Tshudi, 1838) currently comprises 15 species widely distributed in the Neotropical region (Frost, 2011), mainly in dry forests and open areas (Ferraro and Casagranda, 2009; Kolenc et al., 2009). Pleurodema diplolister (Peters, 1870) is the only species in the genus known to inhabit the Caatinga biome (shrub-like vegetation) (Cardoso and Arzabe, 1993). The species is also found in the Brazilian Cerrado and Cerrado-Caatinga transition zones (Andrade and Vaz-Silva, 2012).Pleurodema diplolister is a fossorial and omnivorous frog, and its explosive reproduction shows greater specialization between the anuran communities of the Caatinga (Hodl, 1992; Cardoso and Arzabe, 1993; Santos et al., 2003).Parasitological studies are important to understand host population dynamics, as well behavioral, morphological and dietary shifts, especially within highly specialized anurans such as P.diplolister. To date, only two records of parasitism in the genus Pleurodema are available, all of these by nematodes of the family Cosmocercidae: Aplectana meriodionalis Lent and Freitas, 1948 infecting Pleurodema borellii Peracca, 1895 (Baker, 1980) and Oxyascaris oxyascaris Travassos, 1920 in diplolisterP. (Vicente et al., 1990).Herein, we present data on helminth infection of the frog P. diplolister in the Caatinga of Pernambuco State, Brazil.