What food source do yellowjacket workers prioritize feeding larvae early in the season?

Soft-bodied insects (protein)

The foraging strategy of yellowjackets demonstrates significant evolutionary flexibility dependent on the developmental stage of the colony. During the early phase of the season, the primary focus of the worker caste is supplying the developing larvae with necessary building blocks for growth. This requires a diet heavily weighted toward protein, which they acquire by actively hunting and consuming soft-bodied insects. As the colony matures later in the season, the metabolic needs shift away from rapid larval growth toward maintaining the adult reproductive forms (the new queens and males). At this later stage, the diet pivots significantly toward carbohydrates, sourced from high-energy foods like fruit juices or unattended sugary beverages, which fuel the adults preparing for mating flights.