Question

The goldenrod gall-fly lays its eggs on the terminal buds of goldenrod plants. Larvae chew through the buds and into the stems, where their saliva induces the plant to generate a gall, or outgrowth of tissue, that then provides food and shelter for the developing larva. The larvae are prey to both parasitoid wasps and to birds; wasps selectively prey on larvae inside the smallest galls while birds selectively prey on larvae inside the largest galls. Goldenrod gall-flies are therefore subject to what selection?

Answer 1

Answer:

Stabilizing selection

Explanation:

This occurs when selective pressures occur against the two extremes of a trait (wasps prey on larvae inside the smallest galls; birds prey on larvae inside the biggest galls). As a result, this would select for larvae in medium sized galls, while the number of larvae in small and large galls decreases.