| Randomly sampled oothecae of a natural population of Gratiana spadicea from the outskirts of Porto Alegre, RS, were dissected. The overlapping of the egg membranes makes possible to enumerate the eggs in a batch and therefore to relate mortality to position in the ootheca. The ootheca of this cassid provides a spatial refuge for some of its eggs. Successful eggs of G. spadicea amounted to less than one fifth of the total in each batch. Parasitoids and predators were responsible for a high mortality of eggs whatever the size of the ootheca. The main cause of mortality was the eulophid wasp Emersonella ooecia De Santis, 1983. A large proportion of eggs were sucked dry by the mirid Tupiocoris cincticornis (Stal, 1860). The sucked eggs could have contained... |
