Kathy Doisy

I like bumble bees. This despite a traumatic incident as a small child when I was stung by one (I can still see her coming at me!).  Anyway, I’ve gotten over that, and I do everything I can to encourage them in my gardens, which are filled with them on sunny days. Why do I like them? Well, for starters, they are beautiful, industrious insects that benefit my plants. They also are an important part of our ecosystem and deserve to be here.

We have ten recognized species of bumble bees in Missouri and all of them are important pollinators. However, only four of these species occur commonly: the Common Eastern, Two-spotted, Brown-belted and Half-black bumble bees. Great names, aren’t they?

Bumble bees are great generalist pollinators, meaning that each species may feed on the nectar of several vegetable, fruit or flower crops while collecting and feeding the pollen to their larvae. They are “eusocial” like honey bees, meaning they have different “castes” that perform different tasks for the benefit of the colony. However, they differ from honey bees in that the colonies are much smaller, occur in the ground and only last one year. Newly inseminated queens overwinter before starting a new colony in the spring.

Every year, someone tells me about how a bumble bee was acting territorial with them or other bumble bees. It was hovering about head height and challenging anything that came near. That’s why I decided to write this article. A bee like that isn’t a bumble bee!

Figure 1: Eastern Carpenter bee. Note the shiny, hairless abdomen.

Figure 2: Bumble bee.

If you look closely at a bee acting territorial, you’ll see that it’s abdomen is shiny and hairless (Figure 1), unlike the abdomens of bumble bees (Figure 2). With proper training you would also see that it is a male bee, and unable to sting you despite his bravado. The bee I’m describing is the Eastern Carpenter bee.

To be honest, I set out to show you the difference because I was trained 40 years ago to dislike this species because it damages wood. However, in doing some background reading I’ve come to realize that feelings towards this bee have changed. The Eastern Carpenter bee does damage wood, including unpainted fresh lumber of the pine and cedar varieties. They do this when the female tunnels into the wood so that she can lay her eggs. This species is also capable of being a nectar robber, meaning that it sometimes rips open the corollas of tubular flowers to get at the nectar while failing to pollinate them. However, despite these negatives, researchers now believe that they still do a lot of beneficial pollinating, albeit not at the level of honey bees or bumble bees. So, now it’s up to you to decide what to do about them. When I see them in my garden, I will let them be, but I’ll still net and dispatch any females trying to damage my potting shed.

More information on bumble bees and bees in general:

• A pictorial guide to the bumble bees in Missouri and Illinois
• Use of Bees with Vegetable Crops
• Bumble Bees of the Eastern United States
  (By Sheila Colla, Leif Richardson, and Paul Williams. US Dept Agriculture)
• Bee Basics An Introduction to Our Native Bees
  (By Beatriz Moisset and Stephen Buchmann. A USDA Forest Service and Pollinator Partnership Publication.)

Kathy Doisy

Garden leader Calvin Miles, from Friendship Garden Club, recently asked me a very good question, “What are the good insects?”

Well, first off, we want pollinators. As I mentioned in my last post about “insect hotels,” these include honey bees, bumble bees, solitary bees, ants, butterflies, moths and some flies. Where this gets tricky is that some butterflies and moths are actually laying eggs so their young can devour your crops. I could go on (and on, and on), but, generally, if you see a butterfly or moth hanging around your cole crops or corn it is probably laying eggs because these plants don’t require pollinators. Of course, it may also just be taking a rest. One rule of thumb is that if it’s a pretty butterfly, give it a nudge to move it along. If it returns and especially if it’s white or yellow, get rid of it if you can.

So, beyond pollinating many of our crops, insects may be beneficial to our gardens by consuming other insects and relatives that damage our crops. There are dozens of these beneficials, so I’m just going to address the ones I most commonly see in my Columbia garden. Then I’ll list some good websites for readers who want more information.

Most everyone knows what a ladybug looks like. Maybe you also know that they help our gardens by eating aphids and other small plant pests. Did you know that immature ladybugs do the same thing? They range from a few millimeters to ½-inch in length. Here is picture of one so you know to leave it alone or move it to a plant with an aphid infestation!

Ladybug larva

Another good type of insect to find in your garden is a praying mantis. There are three species found in Missouri, ranging in size from about 2½ to 5 inches, and in coloration from brown to bright green. These feed on most anything they can catch, even including, on rare occasions, hummingbirds. I’ve seen a picture of this and actually found a pair of hummingbird wings mixed in with the butterfly wings beneath one of my Chinese mantises! Survival of the fittest, right? EEK! That said, put a mantis on your green bean plants and forget about leaf damage.

Praying mantis

Lacewings are another great predator. The adults and young both eat aphids, small caterpillars, mites, etc. (and fortunately not hummingbirds). The adults are about ¾-inch long and may be green or brown. Larvae are about a ½-inch long and brown.

Adult lacewing, left. Immature lacewing, right

Stink bugs…are way too complicated. Generally speaking, stink bugs feed on our crops and damage them by sucking fluids. However, a few species of stink bugs suck the juices out of all
kinds of crop-destroying caterpillars. Unfortunately, even I can’t tell the good guys apart from the pest species without a magnifying glass. While all stink bugs have long, tube-like mouthparts, the predators have a broader tube than the plant feeding types. So, unless you find a stink bug in the process of killing something else, you might just go with the odds and kill any that you see. (If you’re game to try sparing the predatory species, though, read to the end for a couple good guides to common species.)

Green stink bug

Another group of beneficial predatory insects I often see is damsel bugs. There are quite a few species you may encounter. The one I frequently see is brown and about a ½-inch long.  These are true bugs (like stink bugs) and, therefore, grab their prey and use tube-like mouthparts to suck the juices from a variety of caterpillars, leafhoppers and other garden pests.

Damsel bug

So that’s just a few of the more common beneficial insects. There are also dragonflies, ground beetles, ambush bugs, assassin bugs, predatory and parasitic wasps, predatory flies, and our non-insect friends the spiders and some mites. To learn more, check out some of the websites listed below.

More information on beneficial insects and how to attract them:

• MU Extension – Increasing Beneficial Insects in Row Crops and Gardens
• Missouri Botanical Garden – Beneficial Insects
• Washington State University Extension – Beneficial Insects, Spiders, and Other  Mini-Creatures in Your Garden
• Wikipedia.org – Beneficial_insects

More information on stink bugs:

• BugGuide – Stink Bugs
• Virginia IPM – Field Guide to Stink Bugs