The Boone County Buzz: How to Foil Flea Beetles

Does it look like a tiny shotgun has blasted the leaves of your eggplant? (See Figure 1 for an example.) Chances are you have a flea beetle infestation. First of all, don’t worry, “flea” beetles only bite plants! These are not like the fleas on your dog or cat. That’s a whole different order of insects. These are very small (1/10 inch) leaf-feeding beetles that are called “flea” beetles due to their large hind legs which enable them to jump much like fleas (Figure 2).

Eggplant with flea beetle damage.

Figure 1. Eggplant with flea beetle damage. Photo, Ali Eminov [CC BY-NC-ND 2.0]

Adult flea beetle

Figure 2. Adult flea beetle

There are several species found in Missouri but the only species I see regularly is all black. Depending on the species, they may feed on cruciferous vegetables, spinach, turnips, radishes, tomatoes, potatoes, peppers, beans or eggplant. The good news is that the adults die off in July. The bad news is, they can have two generations per year, meaning they can come back for your fall crops. Generally speaking I ignore flea beetles and their damage except when it comes to young seedlings. (Mature plants can usually sustain a bit of flea beetle damage to leaves and still provide fruit.)

For years, flea beetles have severely damaged my eggplant transplants. If I’m lucky, a couple plants survive, and, by late summer, I finally have plants that are large enough to produce. I have tried row covers to no avail. The problem here is that the adults overwinter in your soil and leaf litter. Despite clearing the plant debris from my garden in the fall there are still plenty of hungry adult flea beetles just waiting in the soil for some tender eggplant leaves.

Last year I tried an experiment. Since I only grow four eggplant every year, I went out and purchased some hard plastic domed frost guards. Eggplant are notoriously cold sensitive, so why not? In addition, I thought they might act as a physical barrier to hungry flea beetles. I figured if I found any beetles under the dome, I would shoo them off and quickly replace it since flea beetles jump when startled. In practice, I never needed to do this as the domes worked quite well. After a week I checked and the transplants were hole-free. To test my experiment, I uncovered one of my eggplants. Three days later, when I went out to compare it to the still-covered plants, I found that the unprotected plant was COVERED with flea beetles and feeding holes. The domes worked!

FRGD Frost Guards from Gardener’s Edge

Then, in an effort to save my sacrificial eggplant, I tried spraying it with organic neem oil. WOW! Another real find! It took several sprays, but apparently the flea beetles think it tastes as bad as it smells! They either died or left. My eggplant grew up, became highly productive, and I ended up with a freezer full of tasty ratatouille which my sweet husband enjoys.*

While I think I’ve cracked the code on safe ways to control flea beetles, there are some good suggestions on the websites listed below for other earth-friendly ways to lessen flea beetle damage:

* I have the BEST recipe for ratatouille. Email me at if you’d like it.

The Boone County Buzz: Are you a gambler?

I am! No, you won’t ever find me at the casino. I’m talking about gardening! I think most of us who garden have a touch of the gambler in us. How else can you explain the leap of faith we take every year when we put our seeds or baby transplants out in the wild world dreaming of luscious produce to come? Sometimes things go well and some not so well. That’s just part of life.

Well, today I want to encourage the wildest gamblers out there to take a chance on REALLY early spring lettuce. You know how all the seed packages say to plant your lettuce from mid-March to mid-May? I think they’re missing the boat!

mixed baby lettuceI followed those recommendations for years and what always happened was that as my lettuce finally started to head up it became bitter! The bitterness used to start around mid-June but I’ve had it happen as early as mid-May when temperatures are unusually warm. As a crazed, baby lettuce aficionado this is most frustrating.

Then about 15 years ago I was reading some book (?) where an old woman from the Ozarks said to put your lettuce seed out as soon as the snow melted. This seemed like insanity, but, again, I’ve got a gambling streak. I tried it. Yes, I ran out with a cloth sheet to protect it a few times. But I was eating beautiful baby lettuce salads by the end of March! Needless to say, I’ve been doing this ever since.

When exactly do I take this risk? It varies with the weather and snow. Looking back in my garden diary (yes, you really should keep one) the first planting has been as early as January 5th but probably averages around January 25th. Have I lost my lettuce? Maybe once, but most varieties of lettuce can survive temperatures as low as 20 degrees Fahrenheit. Since lettuce seed is somewhat viable for up to 6 years I usually use old seed from a previous year, so if it is lost I won’t feel quite as bad. Sometimes, when the cravings are severe I’ve been known to start lettuce seeds inside in January and plunk the plants out in early February. Again, it’s a gamble but what an incredible payoff if you succeed! Take a chance!

Boone County Buzz: Our Insect Hotel Has Tenants! YAY!

Kathy Doisy

Kathy Doisy

In case anyone is wondering if our insect hotel is working, I have proof! If you look at the bamboo on the lower right, you can see that several of the holes have been covered with green pieces of leaves (Fig.1). This is the work of leaf-cutter bees (Fig.2). In July, a friend found me a mini-insect hotel that was going for cheap at Aldi’s — you know something is getting trendy when Aldi’s starts selling it. Anyway, while it didn’t have quite the flair of the one my beloved made for me, I thought why not? Well as you can see several of the holes have been sealed with mud by mason bees (Figs. 3 and 4).

Bamboo tubes filled with cut pieces of leaf.

Figure 1. Brood chambers of leaf-cutter bees.

Mason bees and leaf-cutter bees are represented by several species in the family Megachilidae. Most of the bees in this family are solitary bees meaning that each female performs all her own tasks, unlike the division of labor in a honey bee colony. She collects pollen on fine hairs on the underneath of her abdomen (this pollen spreads easily to the next flower making them excellent pollinators), then finds an appropriate tube to lay an egg in, while provisioning it with pollen for when her hungry larva hatches.

Picture of small bee on flower

Figure 2. Common species of leaf-cutter bee (USDA ARS free image).

She then seals that part of the tube with either a piece of leaf or mud, depending on the species, and goes looking for more pollen to repeat the process until all the space in that tube is filled. Whew, sounds exhausting! Which is why these small, gentle bees don’t waste their time defending their brood like honey bees. The only way you’ll get stung by one of these is if you grab it.

Image of bamboo tubes sealed with mud that looks like masonry.

Figure 3. Brood chambers of Mason bees.

Now here’s where it gets really interesting — at least to me. I went out to look at our homemade insect hotel and found that a new, different species has recently been using some of the tubes and stuffing the openings with grass (Fig. 5). I did a little research and found out there are several species of “grass-carrying” wasps in the family Sphecidae that also use these tubes for their brood. These wasps aren’t as good at pollinating as our solitary bees, but I’m a big fan of diversity and isn’t that grass cute? I’m hoping to catch one in the act.

Picture of small dark bee on flower.

Figure 4. Species of Mason bee (USDA ARS free image).

Picture of bamboo tubes with long pieces of grass sticking out the ends.

Figure 5. Brood chambers for “grass-carrying” wasps.

I think the take home point of this whole endeavor is highlighted by the fact that we live just a couple of blocks from the massive Brookside student apartment complex. Can sweet little pollinators thrive so close to all that concrete and trash? Apparently, yes. You can live downtown and still help nature. In fact, recent research indicates higher abundance and diversity of native bees in urban areas where there are higher densities of flowers and less pesticide use than fields in rural areas (D.M. Hall, et al. 2017. The City as a Refuge for Insect Pollinators. Conservation Biology 31:24-29.)

So, no more excuses! Start doing your part! Why not put a few native plants along the border of your veggie garden? If you don’t want a perennial, then plant a few annual sunflowers or zinnias. Both are good nectar sources for many insects and make lovely bouquets. For more information on helping these pollinators while producing nourishing food for yourself and friends, take a look at this website:

The Honeybee Conservancy

Boone County Buzz: We Love Squash (So Do Bugs)

round zucchini growingWhen I hear stories of gardeners abandoning cucurbits (AKA zucchini and other squash) on people’s doorsteps, I wish this was my problem. Why do I have trouble growing these plants? I don’t use pesticides. If you want to kill some bees and reduce your yield, treat your zucchini plants with an insecticide.

Kathy Doisy

Kathy Doisy

My first job at MU was on an EPA program called “Rebuttable Presumption Against Registration.” Our job was to send the EPA data on the pros and cons of using various pesticides. Essentially asking whether the risk was worth the benefit. Based on that experience, when it comes to flea and tick control I’m on-board with man-made chemicals. (I apologize to my Kitty Boys but there is nothing worse than a home flea infestation). However, putting chemicals on something I’m eventually going to eat just doesn’t happen unless it’s absolutely, positively necessary. That means that to harvest a lot of squash and other cucurbits I have to do some serious plant monitoring. My methods are working pretty well, as we have gone from losing our plants to insect pests by the first of July, to harvests still going on in September (knock on wood)! My freezer is filled every year with my version of a delicious summer squash bisque! (If you want the recipe email me!)

adult squash bug

Figure 1. Squash bug approximately ½ to ¾ inch long. Photo, Keith Weller, USDA.

When it comes to growing squash or cucumbers around here, the big problems are squash bugs, squash borers and cucumber beetles. Anyone who has ever grown squash two years in a row knows what a squash bug looks like (Figure 1). The squash borer adult is more elusive (Figure 2). Our cucumber beetles tend to be the twelve-spotted variety (Figure 4).

adult squash vine borer, photo by Jesse Christopherson

Figure 2. Squash borer approximately ½ to ¾ inch long. Photo, Jesse Christopherson

Here’s what is working for me with the squash bugs and borers.

First, I clean up my garden waste after the first hard freeze in the fall. This way I’m removing overwintering sites for many pests including the squash bugs. Then in the spring, I plant two separate patches with summer squash as far apart as possible and leave 4 or 5 plants per mound. Depending on your garden size I recommend planting your cucumbers and winter squash in the same fashion. It may be crowded at first but it is inevitable in gardens over a year old that one of these pests will kill some of your plants.

Most mornings I get up early (it’s really nice out then — it’s cool, the birds are singing), I put on my flexible garden gloves, take my 5-gallon bucket of soapy water and an aerial (butterfly) net to the garden. First I sneak up on my plants looking for adult squash borers laying eggs near the base of my plants. It’s their larvae in the plant stems that make your otherwise healthy zucchini plant suddenly collapse and die. If you see one you have to act FAST. I swoop the net on top of it and then hold up the end of the net so they will fly up into it. Catching them on the wing is more difficult, but when you succeed it’s thrilling (well at least for a 62 year-old woman).

Squash bug eggs and immature squash bugs. Photo, Zsofia Szendrei,

Figure 3. Squash bug eggs and immature squash bugs. Photo, Zsofia Szendrei, Michigan State University

Then, when I’m done scouting for those I start looking for adult and immature squash bugs, but more importantly squash bug eggs (Figure 3). These are usually laid in clusters anywhere on the plant. When I see the eggs or immature bugs on a plant leaf or stem I remove part or all of that leaf and plunge it under the water in my bucket. If I see an adult or near-adult bug I crush it with my gloved hand or step on it. I’ve killed thousands and never been hurt, so don’t be afraid to do it.

spotted cucumber beetle

Figure 4. Spotted cucumber beetle approximately 1/3 inch long. Photo, DrPhotoMoto

Unfortunately I don’t have much luck removing cucumber beetles by hand. The damage they do to my cucumbers by feeding is negligible, but they do a lot of damage by transmitting a bacterial wilt, which is why I plant several vines on each patch. Usually one of them makes it! For other ideas on how to deal with these pests, take a look at the websites below.

Missouri Botanical Garden – Cucumber beetles

Missouri Botanical Garden – Squash borers

Missouri Botanical Garden – Squash bugs

The Boone County Buzz: Bugs in Your Broccoli?

Kathy Doisy

Kathy Doisy

“Cruciferous” vegetables include cabbage, broccoli, kale, cauliflower, arugula, and the list goes on. These crops love cooler weather and are known as “super” foods, because they are packed with nutrition. I don’t grow large quantities of them. It’s not that we don’t like them, but from past experience it seems like all the “heading” types become ready to harvest almost simultaneously. If you don’t have a big family or like to do serious fermenting, pickling and/or canning, it may cause more stress than pleasure. So, if you do like broccoli, cabbage or cauliflower, but have never grown them, I have a suggestion. On March 24th and 25th, the CGC will be offering transplants of these cool season vegetables at the Claudell garden. Why not ask for a couple of each? That way you can see how it goes without being forced to get 4-6 of them at the nursery or big box store. Also, please remember when picking up these plants that a donation helps us keep all of this going!

cabbage white butterflies

cabbage white butterflies (photo Masaki Ikeda)

Another reason for the scarcity of these types of veggies in my garden is the large number of insect pests that LOVE cruciferous plants. I don’t like to use chemicals, especially on the parts of a plant I’m going to eat. This means that for each cruciferous vegetable that I do grow I spend a lot of time monitoring it for pests.

When I walk out for my daily garden inspection I’m always wearing lightweight, flexible gardening gloves and carrying a bucket of soapy water. This allows me to crush or drown every garden pest I encounter. (Though bunnies and turtles get a pass.) For someone who has pet spiders in her home, I can be surprisingly vicious when it comes to biological control on my plants. Another possibility is row covers which will at least slow down the flying pests. Our long-time board member Bill McKelvey says that he grew spectacular cauliflower and broccoli last year using row cover, so I’m going to give it a try. The materials for row covers will be available along with seeds and the transplants at the Claudell Garden on the aforementioned dates.

garden beds demonstrating use of row cover with hoops, photo by Mark The Trigeek

Using row cover and hoops over a garden bed. (Photo by Mark the Trigeek.)

Unfortunately, I can think of twelve different species that can wreak havoc on various cruciferous vegetables. I don’t have the time, space or inclination to address all of these potential pests and chemical-free ways to grow them, but fortunately I don’t need to. Below you will find several links where someone has already done it for me.

Identification of cruciferous insect pests:

Earth friendly suggestions for control of some of these pests

(Tip: These sites all offer recommendations on other pests, too.)

The Boone County Buzz: Bumble Bees and Why You Should Like Them

Kathy Doisy

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!

Eastern Carpenter bee

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

bumble bee

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:

The Boone County Buzz: Beneficial Insects for Your Garden

Kathy Doisy

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, photo by Mausy5043

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

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 & immature lacewings

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

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

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:

More information on stink bugs:

The Boone County Buzz: Introducing Insect Hotels

Kathy DoisyHi! My name is Kathy E. Doisy, and I am a new board member for the Community Garden Coalition. I have always admired this organization because it helps so many people, and it’s completely volunteer. I’ve been an avid gardener since 1976, and I’m a retired entomologist so I have a lot of knowledge about gardening and garden pests. As the season goes forward, I’ll be posting timely information about common garden pests in a column we’re calling “The Boone County Buzz.” In the meantime I thought I might suggest a way that you can prepare for next year’s crops and help the environment at the same time.

I think we all know that insect pollinators are important for the production of many of our favorite fruit and vegetable crops. When you mention pollinators most people think of honey bees which are a lovely, beneficial species. But did you know they are not native to North America? They were introduced into the New World by Europeans. However, North America already had a huge diversity of native insects that act as excellent pollinators, including bumblebees, solitary bees, moths, ants, butterflies, and some flies.

I’ve been trying to encourage these native species in my garden for several years because it’s a LOT easier than being a beekeeper! Then I heard about “insect hotels.” Just type that or “bug hotels” into your favorite search engine, and you will be inundated with pictures and articles about how to build one for your yard or garden. I don’t know whose idea this was but it’s a good one! Below are few good websites for your perusal. I encourage you to help our native pollinators while also helping your garden!

How to build an insect hotel:

Detailed information on our native bees:

And here is my own new insect hotel:

Kathy's insect hotel