A female grape root borer Vitacea polistiformis will produce

A female grape root borer, Vitacea polistiformis, will produce an average of 450 eggs (lifetime output). If 90% of these are fertile and hatch into young larvae, how many would have to die of starvation, predation, and disease in order for this population to remain stable (\"R\"=1)?

Solution

the population remains stable as R = 1 is given when there is no added pressure on the food or land

as given that 90% of the eggs are fertile we need to find out the number which should die in order to keep population stable

it means

eggs which will form in larvae = total number of death should happen

as there are 450 total eggs

90% of this will be 405

hence 405 are adding up so 405 should die also to maintain the stability