Saving the rusty patch – one garden at a time
A rusty patched bumble bee visits a wild bergamot flower - a bumble bee favorite! Photo by Jill Utrup/USFWS.
How many times have you watched a documentary showing the plight of an endangered species sliding toward extinction and wondered what you can do to help? We at the U.S. Fish and Wildlife Service have good news for those of you who live in the range of the rusty patched bumble bee: Helping save this endangered pollinator is something you can do without traveling far or spending much money. You don’t even need to leave home – in fact, you can do your part while gardening in your own backyard. Don’t have a yard? No problem – you can still plant containers on your porch, patio or balcony.
Rusty patched bumble bees, listed as a federally endangered species in 2017, were once an everyday sight in summer fields, farms and yards in 31 states and Canadian provinces from Connecticut to South Dakota. Just 20 years ago, the rusty patch was so common, it went almost unnoticed, flitting from flower to flower, collecting nectar and pollen. But in just two decades, its numbers plummeted to the point that extinction poses a real risk to this once abundant pollinator. Now the species occurs only in scattered populations in Illinois, Indiana, Iowa, Maine, Massachusetts, Minnesota, Ohio, Virginia, West Virginia and Wisconsin.
What happened? As is true with many imperiled species, a number of factors played a role in the recent decline of the rusty patch. Disease and pathogens from commercially bred bumble bees, pesticide use, effects of climate change and loss of habitat likely all contributed to the decline, and now, with low population numbers, these threats are especially concerning.
A look at the rusty patch’s life cycle gives a hint to what you can do to help. Rusty patched bumble bees, like many pollinators, need the right kind of habitat to establish their colonies and find food. Rusty patch queens are among the first bees to emerge in the early spring, and are in immediate need of food sources. The queen establishes a colony underground, often using abandoned rodent cavities, and begins to populate it with eggs. Through summer, the queen grows her colony of female workers, then later in the season, she produces males and new queens. At the end of the season, all members die except for the newly produced queens. These new queens disperse, find a place to overwinter, and begin the cycle once again the following spring.
Here's where you can step in and help save the rusty patch
These bumble bees need flowers for food from early spring through fall. Even the lowly dandelion, the bane of suburban lawns, can provide nourishment. Dandelions are sometimes the only food source available to newly emerging queen bees. If you can put up with dandelions, skip mowing in spring and summer where you can, and let them stay!
Of course, there is more you can do to help than merely leaving dandelions in your yard. Here are some other tips if you want to give the rusty patched bumble bee and other pollinators a helping hand:
- Create your own bumble bee habitat, and offer a mix of flowers throughout the growing season. Rusty patched bumble bees are generally active from April through October. Planting a mix of flowering trees, shrubs and herbaceous plants so that something is always blooming during that time can be a real benefit. Native plants are a great choice as they are especially nutritious and typically not treated with pesticides. Need tips on what to plant? Check out our plant guide for rusty patched bumble bees.
- Early spring is important! The only bumble bees that survive the winter are queens, which mated the previous year. The future of bumble bees depends on these queens as they emerge and look for nest sites and start laying eggs. Help them start new colonies by providing spring flowers that bloom quickly. Early blooming flowering trees and shrubs are great options.
- If you discover a bumble bee nest, great! Nests are a rare find. Leave the nest be – it will be occupied only until the fall.
- In fall, leave some areas of your yard unraked or pile leaves and branches at the edge of your yard or garden beds. Rusty patched bumble bee queens use these places to overwinter.
- Avoid pesticides as much as you can. Pesticides, especially insecticides, can harm bumble bees and other pollinators (they’re insects, after all!). And herbicides used on weeds can reduce food sources by removing flowers from the landscape. If you do need to use pesticides, limit use and follow instructions carefully.
A few fun facts about bumble bees:
- Bumble bees are great pollinators because they “buzz pollinate.” They are able to produce vibrations to loosen hard-to-get pollen, resulting in an explosion of pollen that provides food for the bee but also boosts pollination.
- Unlike honeybees, which maintain hives of up to 10,000 individuals over several years, bumble bee colonies only survive from spring to fall, with up to 1,000 bees. Only the new queens survive the winter.
- Female bumble bees very rarely sting when threatened, and males are not able to sting at all. In general, bumble bees are very docile and would prefer to go about their business collecting nectar and pollen rather than mess with us humans!
- Rusty patch queens produce female bees all summer. Only in late summer do they produce males and new queens.
- All rusty patched bumble bees have entirely black heads, but only workers and males have a rusty patch on their backs.
- Bumble bees are important pollinators of crops including blueberries, cranberries and clover. Bumble bees, including the rusty patched, make up the predominate group of insects that pollinate tomatoes.