The Incredible Diversity of Iowa Bees

The Incredible Diversity of Iowa Bees

June is National Pollinator Month! While many animals can act as pollinators (from bats to butterflies to beetles), this month we are choosing to celebrate the most efficient pollinators of them all: native bees!

Iowa has nearly 400 species of native bees. While the word “bee” brings the honey bee (Apis mellifera) to most people’s minds, this is just one species of bee and it is not native to Iowa; they were brought to the States by early settlers. Unlike honey bees, nearly all of Iowa’s native bees are solitary, meaning one female bee creates and tends her own nests. There are too many bee groups and species to cover in one article, and therefore we are focusing on only eight common groups of bees in Iowa to appreciate this month: bumble bees, cellophane bees, sweat bees, mining bees, mason bees, long-horned bees, leafcutter bees, and carpenter bees.

Bumble Bees
One of the most beloved groups of bees, bumble bees are large bees that look chunky and fluffy (what’s not to love?). They nest above or below ground in abandoned burrows or cavities, and are Iowa’s only truly social native bees! Their colonies can be large but only live for one year. Near the end of the hive’s life, young queens hatch and leave the hive to hibernate alone during winter, then emerge the next year to start their own hives. An easy way to tell bumble bees apart from large carpenter bees is that they have fuzzy abdomens, while carpenter bees have shiny black, nearly hairless abdomens.

Common Eastern Bumble Bee

Cellophane Bees
Also known as plasterer bees or polyester bees, these fuzzy friends are in the bee genus Colletes. They are known by a wide range of plastic-alluding names due to the plastic-like coating they create to line their underground nest cells. The plastic-like substance acts like waterproofing, protecting eggs and developing larvae from moisture, fungus, and other threats. Cellophane bees are active in spring here in Iowa.

Cellophane Bee

Sweat Bees
Bees in the sweat bee group belong to the family Halictidae. They come in a vast array of colors, sizes, and nesting strategies; there are about 500 different species of sweat bees in North America alone! My favorite genus of sweat bee may be Augochloropsis; these bees have green, comma-shaped wing shields (also called tegulae), are a brilliant blue-green color, and there’s even a bee with the species name metallica! Other sweat bee genera range from metallic to dull brown in color, with many nesting in the ground. While not truly social, some sweat bees nest communally by sharing main tunnels underground, similar to how we share hallways in apartment buildings!

Sweat Bee

Mining Bees
This group of bees often includes bees in the Andrenidae family. These bees excavate their nests in the ground and come in a range of sizes. These bees are currently active in Iowa! Look for their nests by finding small piles of dirt around a hole the size of a #2 pencil (though the size of the hole varies between species). You may find more than one nest in an area!

Mining Bee

Mason Bees
Belonging to the genus Osmia, this group of bees is especially important for the pollination of fruit and other crops! They are also in the same family as leafcutter bees (Megachilidae). They are beautiful metallic bees here in Iowa and are active in spring. Some species are cavity nesters, so they may occupy a bee hotel if provided! Alternately, some species make their nests entirely out of mud, a trait that earned them the nickname “mason bee”.

Mason Bee

Long-Horned Bees
Aptly named for their long antennae, most species of long-horned bees nest in the ground. Only males have amazingly-long antennae, sometimes nearly reaching the length of their entire body! Many bee genera belong to the long-horned bee group. Some species are very fluffy and are consequently called “teddy bear” bees, which is probably the cutest nickname in the insect world!

Longed Horned Bee

Leafcutter Bees
Belonging to the genus Megachile (meaning “big-lipped” in Greek), many leafcutter bees have huge jaws that cut pieces of leaves with which to line their nests. These bees mostly nest above-ground and may utilize your bee hotel. While many bees store pollen on their hind legs, leafcutter bees are unique in that they collect and store pollen using the underside of their abdomen! There they have thick, broom-like hairs called scopa that sweep up and trap pollen during flower visits.

Leafcutter Bee

Carpenter Bees
Did you know that there are two main kinds of carpenter bees? There are the large carpenter bees that you are probably familiar with, which can look similar to bumble bees. However, there is a second, lesser-known group of tiny carpenter bees belonging to the genus Ceratina. These tiny carpenters chew down the pithy centers of stems and twigs to form rows of nest cells. These bees are one of the reasons to dead-head your flowers and leave the stems standing at the end of the growing season; you’re providing a nesting site for tiny bees! Also, some species have the coolest cream-colored spot on their nose.

Carpenter Bee

There are countless details in the bee world to learn and appreciate. This is by no means an exhaustive list of all of the bee groups and their quirks occurring in Iowa, much less the rest of the world. For instance, I didn’t even mention parasitic bees, which are bees that don’t make their own nests or collect pollen for their young; instead, they steal it from other bees! Next time you are outside on a sunny day, take a moment to focus your eyes on a smaller scale and look for flower visitors; you may meet someone new!

Take it Easy for Pollinators This Spring!

Take it Easy for Pollinators This Spring!

Signs of spring and warmer weather can be energizing, motivating us to start spring-cleaning our homes inside and out. However, some pollinators are still resting in their winter homes, and cleaning up your lawn too soon can be detrimental to the new generation. For some spring lawn care tips that support pollinators continue reading below!

Pollinators either migrate to warmer climates or go through a phase called “diapause” to survive the harsh winters of Iowa.

Diapause is similar to hibernation in which an insect pauses any development and stays in a kind of suspended animation until conditions are more favorable. There may be many insects in your yard that are still hibernating under leaves or inside flower stems waiting for warmer weather in order to emerge. Rushing to clean up all your leaves and brush now can disturb and damage these pollinators so it is best to leave some “messy” areas in your yard as long as possible. Waiting until the end of May, a time of year when day temperatures consistently reach 50 F (usually), is best. Taking it easy and waiting until later in the spring to tidy up is the easiest way to support pollinators at home!

One specific way to protect pollinators until they emerge is to leave the leaves that have accumulated in your yard. Bumble bee queens especially love to overwinter under layers of leaves as it provides them an insulating layer that protects them from the wind and cold. While you may not want leaves covering your entire yard this spring, leaving the leaves in your garden beds, in particular, can not only protect the pollinators resting there but may also provide you with some composting and weed-suppressing services. Additionally, leaving last year’s flower stems in the garden and not cutting them back until late May will give most stem-nesting bees a chance to emerge as well.

An additional option to support pollinators is to participate in No Mow May, a campaign started by Plantlife in the UK and spearheaded here in the US by Bee City USA, run by the Xerces Society. The goal of No Mow May is to keep your mower in the garage until June and allow floral resources such as dandelions and clover to spring up in your yard providing early pollinators with food resources. Waiting to mow also means the longer grass is able to provide more cover for other insects needing shelter.

While we all want to support pollinators and enjoy them in our yards this year, it can be difficult to allow your lawn to look a bit wilder and to your neighbors, it may look a bit messy. They may not understand that your yard isn’t a mess – it’s a habitat for pollinators! There is much pressure to maintain the traditional, yet outdated, yard of green turf grass containing little to no diversity. To address these concerns we provide the following solutions:

  • Start taking it easy on your backyard
    If your front lawn simply must remain manicured, set aside your back yard to leave the leaves and flower stems and not mow until May. This will still help pollinators and make the pollinator habitat less visible from the street.
  • Create a “Cozy Corner”
    If you can’t put aside your entire back yard, try leaving an unused area in the yard undisturbed. You can create a “cozy corner” for pollinators throughout the coming growing season by leaving the leaf litter there undisturbed and by adding twigs, branches, and other brush to the area as you clean up. This cozy corner can provide shelter for not only insect pollinators, but birds as well! Adding layers of brush to your cozy corner will ensure it serves as an excellent shelter for birds and a fantastic nesting site for pollinators, especially for overwintering. It is also a fun family activity that can be built upon throughout the year!
  • Educate your neighbors
    Let your neighbors know that your yard is providing a specific and important purpose and that it may mean they will be able to enjoy more butterflies and bees in their garden this summer. Here’s a link to free signs created by the Xerces Society you can print out and place in your yard. Spread the word about how you are helping pollinators. Ask others to join you!

There are many ways to support pollinators at home. Many people are starting the fun process of gardening for the foraging needs of pollinators by growing native flowers. However, few people think about the nesting resources that pollinators require. Be mindful with yard clean-up by taking it easy this spring and finding an area to leave undisturbed throughout the year. It will aid in pollinator emergence and provide them with nesting sites. Have a happy and relaxing spring!