Because yellowjackets do not produce or store honey one might wonder why striped skunks, raccoons and black bears frequently dig up their underground nests. It is the young yellowjackets (larvae), not honey, that is so highly prized by these insect-eating predators. At this time of year it is crucial for them, especially black bears who go for months without eating or drinking during hibernation, to consume enough protein to survive the winter.
Whereas adult yellowjackets consume sugary sources of food such as fruit and nectar, larvae feed on insects, meat and fish masticated by the adult workers that feed them. This makes the larvae a highly desirable, protein-rich source of food. (Yellowjacket larvae reciprocate the favor of being fed by secreting a sugary material that the adults eat.)
Three to five thousand adult yellowjackets can inhabit a nest, along with ten to fifteen thousand larvae. Predators take advantage of this by raiding the nests before frost kills both the adults (except for fertilized young queens) and larvae in the fall. Yellowjackets are most active during the day and return to their underground nest at night. Thus, animals that raid them at night, such as raccoons, striped skunks and black bears, are usually very successful in obtaining a large meal. Occasionally, as in this photo, the yellowjackets manage to drive off predators with their stings, leaving their nest intact, but more often than not the nest is destroyed and the inhabitants eaten. (Thanks to Jody Crosby for photo op of yellowjacket nest (circled in red) dug up by a black bear – note size of rock unearthed.)
A Bald-faced Hornet colony begins in the spring when a queen emerges from winter hibernation. The queen builds a small nest, creates a few brood cells within the nest, deposits eggs in them and feeds the larvae when they hatch. These larvae are female workers — they will continue the nest building, food collection, feeding the larvae and protecting the nest while the queen concentrates on laying eggs.
During the summer the colony (and size of the nest) grows until there are between 100 to 400 workers. Toward the end of the summer the queen lays two special types of eggs. The first will be, like the workers’ eggs, fertilized eggs that will develop into females, but these females will be fertile (and develop into queens). The second group of eggs will be unfertilized eggs. These eggs will develop into fertile males. The maturation and emergence of the new queens and the fertile males marks the end of the functioning of the colony. At this point the workers are not replaced and die out. The ruling queen, having served her purpose, also dies. The newly-emerged adults (queens and fertilized males) leave the nest, mate, and the fertilized queens overwinter and begin their colony cycle all over again in the following spring. Some small nests complete their cycle by mid-September, while some large nests are still going strong until the cold kills the larvae in late November.
Monarch Butterflies are not the only insects whose lives are dramatically affected by the current precarious health of the Common Milkweed population. Clockwise, starting middle, top: Yellowjacket worker chewing insect to feed to larvae; White Admiral drinking nectar; Jumping Spider drinking fly innards; deceased butterfly trapped by getting proboscis caught in stigmatic slit ; Small Milkweed Bugs mating; Assassin Bug feeding on ant; Red Milkweed Beetle; Virginia Ctenucha Moth drinking nectar.