State of knowledge of viviparity in Staphylinidae and the evolutionary significance of this phenomenon in Corotoca Schiødte, 1853

Abstract

Viviparity is characterized by the retention of fertilized eggs in reproductive tract of the female. This condition is very common in vertebrates, but relatively rare in invertebrates, including insects. The present work presents a review on viviparity in Staphylinidae, with special attention on genus Corotoca Schiødte, 1853. The genus is composed by six termitophilous species with neotropical distribution, and together with Spirachtha Schiødte, 1853 are only two genera with species confirmed as viviparous in the family. Some other cases are only supposition. Also, it is presented information and discussion on the life cycle of Corotoca species based on dissection of females in laboratory and field observations. During the dissection of females of four species of Corotoca it was observed that each female carries three eggs at the same time. The embryos present asynchronous development: when one is located at apex of abdomen, the other two are at IV segment, on abdomen curvature. These observations are complementary with those obtained in field observation, when the female deposits a larva outside the nest, on the foraging trail of termite Constrictotermes cyphergaster (Silvestri, 1901). The strategy of Corotoca species focused on the immature as dispersing agent is derived and probably favor the fitnees in relation to a hypothetical condition in which the adult is the dispersive agent.