In a food chain:rose→greenfly→ladybird→blackbird.What will happen if the greenflies will no longer exist?

If greenflies were to no longer exist in the food chain, it would disrupt the balance of the ecosystem. Without greenflies as a food source, the population of ladybirds would decrease as they would have less food to eat. This would then lead to a decrease in the population of blackbirds, as they rely on ladybirds as a food source. The absence of greenflies could potentially have a cascading effect on the entire food chain, leading to imbalances and potential population declines in other species as well.