The survivorship curves suggest that the B.
pilosa extract caused in the 30 day old snails a
delayed effect, indicating a strong residual effect on
snails in this life stage, that was not observed in newly
hatched snails that presented a fast reaction to its
toxic effects. These results demonstrate that there is
a difference in the snail response to the molluscicide
according to the life stage. Souza et al. (1992) verified
more sensibility of newly hatched B. glabrata to the
extract of Anacardium occidentale (Anacardiaceae).
Nascimento (2006) verified molluscicidal activity of
extracts of Allamanda cathartica L. (Apocynaceae)
in newly hatched Bradybaena similaris (Férussac
1821) (Bradybaenidae) while in adults was only
checked the repellent action. This distinction can be
related to the energy content of individuals at different
life stages. During the exposure to molluscicides,
the reserves of stored energy can be reduced due to
the stress caused, as already verified for B. glabrata
(Mello-Silva et al. 2006a,b), therefore, reducing its
energy resources to the future survival.