Mud dauber wasps are busy

This week while going through some items in a storage shed, I came across a beautiful dried ball of mud inside an antique trunk. It was the nest of a wasp known as a mud dauber.

When we think of wasp nests, usually the first thing that comes to mind is the papery nest of the paper wasp or the football-shaped nest of hornets. Mud daubers build their nests out of mud. There is plenty of mud for the wasps this summer because of the regular rains we’ve been having.

Mud daubers are not social insects like paper wasps and the others. Instead, they spend their lives as single, solitary insects. They do everything by themselves including, building a nest, laying eggs and collecting food for their young.

There are many different species of mud daubers in Michigan, this one is called the “black and yellow mud dauber”.

The adults look similar to the more common social wasps but are larger and have exaggerated features like the thread-like connection between their abdomen and thorax.

The female mud dauber builds the nest by collecting mud along the edge of puddles. Using her mouth parts, she rolls the mud into a ball then lifts it into the air and carries it to the nesting site. There she adds the mud to her nest, building rooms or cells for her young. Each cell is big enough for one young mud dauber.

The entrance to the nest is sealed shut. She must be out working collecting mud or food for her young.
Here she is, busy plastering new mud on her nest.
The entrance to the nest is open, she must be nearby.


While the female is away from the nest gathering mud or foraging for food, she temporarily closes the entrance to her nest to keep predators away from her young. During that time, the daubers are in the larval stage of their life cycle.

The female also packs away food for the developing larvae by placing insects or spiders into each cell so the larva has enough food in its cell to carry it through its growing stage. Some types of mud daubers only prey on spiders while others prefer caterpillars or other insects.

The entrance to the nest is closed shut. Mama mud dauber must be out collecting more mud or insects for her young.
The entrance to the nest is closed shut. Mama mud dauber must be out collecting more mud or insects for her young.

The prey is only for the young though. The adults feed on nectar, honeydew from aphids or other sugary liquids. Sometimes you can spot them sipping sugar water from hummingbird feeders.

Unlike other wasps and hornets, mud daubers don’t defend their nests. They are not aggressive and rarely sting. Although if you try hard enough you can sometimes provoke one into stinging you.

According to one university website, some species “sing” while building their nest! Mine didn’t seem to be in a singing mood when I found her.

They are generally considered beneficial insects because they eat other insects. You could argue that the spider-eaters are not very beneficial because spiders eat insects too — that is unless you hate spiders.

Most of the time we don’t notice the daubers until they build a nest somewhere where we don’t want it. Some people destroy the nest as soon as they find them.

There seems to be a small industry built around exterminating mud daubers and getting rid of their nests. I prefer to let leave them alone and let them go about their business.

I’ve noticed other smaller species of mud dauber wasp around too. They are not shy and can be very annoying as they buzz around looking for small holes to use for building their nests.


Monarch butterflies with wing tags

Monarch butterflies are on the move heading south on their annual migration. Look closely next time you spot a Monarch and you might see a flash of white against the orange and black pattern of their wings, it very well could be a marked butterfly.

We spotted one last week near Ann Arbor. It was flying and feeding on flowers in the Matthaei Botanical Gardens.

I mentioned in a previous blog how the Monarch population has dwindled. Several groups, professional and amateur alike, are studying Monarchs trying to learn more about their behavior during migration. The butterfly we found was tagged by someone working with a group called Monarch Watch, a conservation education and research organization.

Each ultra-light weight polypropylene wing tag has an identification number and an email address printed on it to report your find.

I would like to think that we found “our” butterfly after it flew and long and arduous journey from somewhere far, far away. But it could just as well have been tagged and released that day by someone nearby.


Tags are placed on a specific spot on the wing to minimize any impact on the butterfly's ability to fly.
Tags are placed on a specific spot on the wing to minimize any impact on the butterfly’s ability to fly.

All tagging information is placed in a data base. Monarch Watch contacts both the tagger and the person finding the butterfly with the location of where it was tagged and found and, how far it traveled.

Most of the tagged butterflies in the United States and Canada are found dead. Ours however looked to be a strong flyer.

Reporting tagged butterflies helps researchers learn how Monarchs move across north america to their wintering places in Mexico.




Apple maggot flies

I’ve seen noticeably fewer insects in my garden this year. It’s probably due to the relatively cool temperatures we’ve been having this summer, especially at night.

While looking at my apple trees this week I noticed some funny little insects flitting around the leaves and fruit — they were apple maggot flies. It is the larval stage of this fly that causes brown streaks inside infested apples.


Apple maggot flies have a distinct pattern on their wings. They are somewhat smaller than a house fly.
Apple maggot flies have a distinct pattern on their wings. They are somewhat smaller than a house fly.

Normally, the early varieties are the ones that really get hammered by apple maggots. However this year, my early apples were free of those pests. My guess is that because of the weather, the flies took a little longer than usual to develop and were not around around in sufficient numbers to cause any noticeable damage.

Now that I’ve picked all of my very early summer apples, the maggots have moved over to the other later varieties that have apples still developing. The adult flies are looking for apples on which to lay eggs. The eggs will hatch into those pesky maggots that ruin so many apples.

The storm front moved through yesterday and the rain has ended. That gave me a chance to spray my trees this morning to knock back those apple maggot flies. I like to spray early in the morning when the air is calm and spray material is not being blown back in my face by wind.

There are other ways of controlling apple maggot flies that take more time such as trapping adult flies, or wrapping each individual apple to protect it from egg-laying flies.

I suggest you spend some quiet time with your trees soon and look for apple maggot flies. If you find them, use your control method of choice. Your trees will reward you with pest free apples.




Milkweeds for monarchs in the garden

Back when I was a kid, it seemed like milkweeds were everywhere. We used to play with the ripe pods by breaking them open and letting the seeds blow away in the wind. I remember asking my Grandfather why they were called milkweed. He told me it was because when you cut the stem, it oozes out sap that looks sweet and milky. He also told me not to try the sap because it didn’t taste good. Of course, later, when he wasn’t looking, I decided to taste the sap, yuk!

Milkweeds have had a checkered past. Sometimes they were considered just a weed that needed to be weeded out of farm fields and gardens. Other times they were highly desirable. For example, during World War Two, ripe milkweed pods were collected and processed into filling for life jackets. The weed helped to win the war in the Pacific.

After WWII, they were once again considered a nuisance. Now, milkweed is rapidly becoming everyone’s favorite weed, or should I say native plant. This is because milkweed is the sole source of food for Monarch butterflies. Without milkweed there are no Monarchs.

With the eradication of milkweed, the Monarch population has crashed from one billion individuals down to around 33 million.

There is a huge and growing effort to allow more milkweed to grow for the sake of the butterflies. The easiest thing for gardeners to do is just leave a few milkweed plants grow in the corner of the yard or garden. Since they are a perennial “weed”, they take absolutely no effort to maintain.

There are more than one species of milkweed in Michigan. Here in our yard we have two different types. The first one blossomed early in the summer and has large pods growing on it already.

This milkweed has large pods aready.
This milkweed has large pods already.


The other is a smaller plant that is just finishing blooming this week. The second type has a wonderful fragrance.

This milkweed flowers later and has a different growth habit.
This milkweed flowers later and has a different growth habit.


Monarch butterflies are out and about in southern Michigan. These are breeding adults. I’ve only seen two so far at our place but other people I have talked to said they have seen several.

By growing milkweed you not only help the overall Monarch population but you get to enjoy watching the butterflies attracted to your garden.



Cabbage root maggot symptoms

If you have never seen it before, it seems perplexing — one or two dying cabbage plants in among a row of healthy plants. This is the work of the cabbage root maggot.

These maggots are the larval stage of a fly that looks very similar to a housefly, only smaller. And like houseflies, they go though part of their life-cycle as a maggot. They attack all plants categorized in the cabbage family which includes cabbage, broccoli, cauliflower, brussels sprouts and others.

Cabbage displaying cabbage root maggot symptoms.
Cabbage displaying cabbage root maggot symptoms.

During the time when the adults are active, they buzz around looking for suitable plants — such as your broccoli or cauliflower. The female fly lays its eggs right where the stem of the plant meets the soil. When the eggs hatch, the larvae begin feeding on the roots.

Infested plants lose so many roots to maggot feeding that they can’t sustain themselves so, the plant begins to wilt and eventually  dies.

Cabbage root maggots thrive in a cool, wet soil environment. Our early rainy growing season has provided ideal living conditions for this pest which is why you may be more likely to see them in your garden this year. Warmer drier weather will help reduce the incidence of this pest.

By the way, if you’ve ever come across wormy radishes or turnips, you’ve seen cabbage root maggots — they’re the same insect.

Predatory insects vs insect pests in the garden

Not all predatory insects live above ground like ladybugs and wasps. Many spend much of their lifetime underground.While weeding my onions, I had a chance to see a life and death struggle between a predatory insect and its prey — a cutworm larva.

Normally, cutworms  stay underground during the daytime but, my weeding disrupted the soil and brought it to the surface. A species of ground beetle noticed the cutworm too. I stayed very still so not to scare away the beetle. Sure enough, it attacked the cutworm. A major battle was underway that lasted several minutes. You can probably guess who I was rooting for.

The cutworm successfully fought off the ground beetle by a lot squirming and biting.
The cutworm successfully fought off the ground beetle by a lot squirming and biting.

The sun was very bright and was taking its toll on the beetle — he eventually gave up. The cutworm  crawled away as fast as it could to find shelter.

My idea was to pick up the worm and toss it to the chickens as a snack. But just before the cutworm ducked under some leave litter, a tiny insect — not much more than one-sixteenth of an inch long  — flew in out of nowhere. In a split second, it lightly landed on the cutworm then just as quickly flew away.

It was a predatory wasp that stung the worm and laid a clutch of eggs under the cutworm’s skin.

Those wasp eggs will immediately hatch and the wasp larvae will begin feeding on the innards of the cutworm.

I let the worm go so that the wasps could complete their life-cycle.

In the struggle between predator and prey insects, the cutworm may have won the battle but it lost the war.


Young ladybugs in the garden

Ladybugs are the most well-known beneficial insects in our gardens.  With their spotted  orange body, adult ladybugs are immediately recognized by everyone, even young children.

It’s the adult stage of the beetle that we usually see. But, if you look closer sometimes you can find the larval stage. The larvae are not as attractive as the shiny adults. Some people say they look like little alligators.


Ladybug larva on peony bud looking for aphids to eat.


Beginning gardeners get concerned when they see these insects. Not realizing that they are young ladybugs, they reach for the insecticide to kill them, “just in case”.

The larval stage eats as many insect pests as do the adults.  As a matter of fact,they’re out there roaming the garden right now looking for harmful insects to eat.

Keep in mind that insecticides — even organic ones — will kill all insects, both good and bad. So, keep an eye out for these garden helpers before you decide to spray.


Gypsy moth eggs hatch

Those of you who are regular readers of this blog may remember a post from last fall. It was about a gypsy moth caught in the act of laying eggs. I decided not to destroy that eggs mass.

Last week, the eggs hatched. In the photo you can see how small and seemingly helpless they are at this stage of their life. They are less than one-sixteenth of an inch long. A single rain drop could probably crush a baby caterpillar if it landed right on it. Or, at the very least, wash it from the tree branch.


Over one hundred gypsy moth caterpillars hatched from this egg mass.


So how do these small caterpillars survive our spring rain storms?

Looking at the egg mass, I think I figured it out. The mama gypsy moth lays her eggs on the underside of a branch where the baby caterpillars are well protected from direct rainfall. I’m sure many get washed away but many survive to live another day.

This is also the stage at which they are most vulnerable to insecticides. You can imagine it wouldn’t take much spray to kill these pests now compared to later in the season  when they have grown into full-sized caterpillars.


Baby grasshoppers hatch inside terrarium

Spring arrived early this year, at least that’s what some grasshoppers at our house thought.

Last fall we planted some small, glass terrariums using plants growing in pots outdoors. We used a variety of tender succulent plants which meant we had to bring them inside so they wouldn’t die from the winter’s freezing temperatures.

This week we discovered a family of baby grasshoppers  had hatched inside one of our terrariums. It looks like there are about 30 of them in there.

You’ve probably heard the saying “cute as a bug”, well these little guys really are that cute! You rarely see them at this stage because they are so tiny and they are the favorite food of a wide variety of predators. Just a small percentage ever make it to be full-sized adults.

This grasshopper nymph is only a few days old.
This grasshopper nymph is only a few days old.

Grasshoppers spend the winter underground in the egg stage of their life cycle. They hatch in the spring when the temperatures warm up — that is known as the nymph stage. The nymphs look like a miniature versions of adult grasshoppers except they don’t have wings. They’ll earn their wings later on in the season.

The nymphs look like miniature grasshoppers -- minus the wings.
The nymphs look like miniature grasshoppers — minus the wings.

In our case, an adult grasshopper laid its eggs in the soil of a potted plant we had outdoors. When we transplanted the plant, we accidentally brought along the grasshopper eggs. The eggs spent the winter in our home inside the terrarium. There they transformed into nymphs and hatched out.

They’re safe and sound behind the glass — for now. When the weather warms up, I plan to release them outside where they will have to fend for themselves.


Autumn Aphids on Brussels Sprouts

Our killing frost finished off the rest of the vegetable plants in my garden. The only ones left were the cold-tolerant  types like Brussels sprouts, kale, turnips and a few others.  I thought that I could coast along until it was time to harvest those crops later next month.

Earlier this week, I went out to the garden to check my Brussels sprouts. I was surprised to find the sprouts covered with aphids and the leaves infested with active cabbage worms. Apparently, our warm Indian summer stimulated a population explosion of insects.

I put away the sprayer for the season a couple of weeks ago. So, I dragged it back out and filled it with a solution of Pyola insecticide. This is a very safe and effective spray for most garden insects. It is basically canola oil combined with a small amount of pyrethrum and is approved for use in organic gardens.

A shot of Pyola insecticide should take care of these aphids.

After thoroughly drenching my Brussels sprouts, I triple-rinsed the sprayer, dried it out and put it back into storage. Hopefully, that will be the last time it will see the light of day until next spring.