All stages of M. scalaris were investigated and described based on
morphological characteristics of larva, pupa and adult stages. The results of the
biological studies under laboratory conditions (25 ± 2 'C & RH 80 ± 5 %) indicated
that the incubation, larval, pupal, preoviposition, oviposition and postoviposition
periods were 1 ± 0.0, 4.43 ± 0.14, 6.8 ± 0.08, 1.2 ± 0.08,4 ± 0.45 and 2.5 ± 0.16 days,
respectively. The life span of M.scalaris was 19.93 ± 0.82 day. M.scalaris females showed differences in their oviposition rates in response
to alive and dead snails. However, M.scalaris females exhibited higher response to
lay eggs on dead (53.75) as compared to alive snails (20.75 eggs I female I day). The efficiency of the parasitoid, M.scclaris 3^rd instar larvae was affected by
the host species. The parasitoid recorded a relatively higher K-values in response to
E.vermiculata than M.cartusiana at all tested densities,