Hullin 58: Mosquito Years

What is the status of a treyfa animal after it has been declared a treyfa? For example if a hen is deemed a treyfa, what is the story with her eggs, for example? It will depend on whether the "father" of the eggs was also a treyfa, if the eggs were unfertilized, and the timing of when the eggs began growing (before or after the treyfa status). Also, worms in a melon when it grows from the ground or in dates that are stored in a jar -- when is that a problem of kashrut or not? Based on the presumption that invertebrates don't survive 12 months. Plus, mosquitos who officially lasted 7 years, but, apparently, that's not a real issue for the count.