By Scout Nelson
Bumblebees are among the most important pollinators found in gardens, farms, and natural landscapes. These insects help pollinate many flowers, fruits, and vegetables, making them valuable to both agriculture and the environment. Their ability to survive cold winters and return each spring is one of nature’s most remarkable processes.
Many gardeners enjoy growing annual and perennial plants that attract pollinators. During the growing season, a variety of insects such as bees, flies, and wasps visit flowers in search of nectar and pollen. This information is shared by Carrie Knutson, Horticulture agent, NDSU Extension – Grand Forks County, who highlights the importance of pollinators and explains how bumblebees survive North Dakota’s challenging winters.
Among the many pollinator species, bumblebees are often easy to spot because of their large size and fuzzy bodies. Species such as the Hunt’s bumblebee and the brown-belted bumblebee are common visitors to flowering plants. They can often be seen moving from bloom to bloom throughout summer while gathering food.
To understand how bumblebees survive winter, it is important to learn about their life cycle. During the warm months, a queen bumblebee starts a new colony. She finds a suitable nesting site and begins laying eggs. These eggs develop into female worker bees that take over many colony duties.
Worker bees collect nectar and pollen from flowers, feed developing young, and help maintain the nest. Their efforts allow the colony to grow throughout the summer. As more workers emerge, the colony becomes stronger and more active.
Later in the season, the colony produces male bumblebees and new queens. The main role of the males is to mate with the newly produced queens. Once they leave the nest, males and young queens search for mates from different colonies. This process helps maintain healthy bee populations through genetic diversity.
After mating, the life cycle of most colony members comes to an end. The original queen, male bees, and worker bees do not survive the winter. Their lifespan is limited, and they eventually die as temperatures become colder. Only the newly mated queens carry the next generation forward.
Before winter arrives, these young queens prepare carefully for the months ahead. They feed on nectar and pollen to build energy reserves. Nectar provides carbohydrates, while pollen supplies protein and important nutrients. These stored resources help the queens survive during their long dormant period.
As winter approaches, newly mated queens search for safe places underground. They usually settle just beneath the soil surface, where they remain protected from harsh weather. During this time, they enter a dormant state known as diapause.
Diapause is similar to hibernation in insects. It allows bumblebee queens to significantly slow their body functions and conserve energy until spring returns. Environmental factors such as cooler temperatures and shorter days trigger this natural survival process.
Winter conditions can be difficult, especially in northern regions where temperatures often fall well below freezing. However, nature provides important protection. Snow cover acts as a natural blanket over the ground. Layers of leaves and plant materials also help insulate the soil and reduce extreme temperature changes.
Because of this, gardeners can play a valuable role in supporting pollinator populations. Leaving fallen leaves and plant residue in garden beds during autumn creates better overwintering habitat for bumblebees. These materials help trap snow, insulate the soil, and increase the chances that queens survive until spring.
When warmer weather arrives, the surviving queens emerge from their winter shelters. Their first task is to find nectar and pollen to rebuild energy. They then begin searching for suitable nesting locations where they can establish new colonies.
After laying eggs, the queen cares for the developing young until the first workers emerge. This usually happens within three to four weeks. Once worker bees begin foraging, they take over food collection and nest maintenance duties. The queen then focuses mainly on producing more offspring.
This cycle repeats every year and helps maintain healthy bumblebee populations. Although only a small number of queens survive the winter, they successfully create the next generation of pollinators that support plants, gardens, and agricultural crops.
Photo Credit: pexels-robert-schwarz
Categories: North Dakota, General