Squash vine borer defense

Squash vine borers are one of the most insidious insect pests in the garden. They attack many vine crops in the vegetable garden especially pumpkins, winter squash, summer squash such as zucchini yellow crook neck, and gourds. Sometimes they will infest muskmelons, watermelons and cucumbers. I’ve had many times in squash and only once in cucumbers.

Although the adult stage of the borer is a moth, it doesn’t look like or act like a moth. Unlike most moths it flies during the day. And instead of fluttering around like a moth, it flies quickly, like a wasp.

The female adult lays its eggs on the base of the main vine, the eggs hatch and the baby borer eats its way into the vine and keeps feeding for about four weeks. It’s very possible that our squash and pumpkin vines have borers in them right now even though they are not exhibiting any visible symptoms.

At first it’s easy to confuse borer symptoms with drought. The plants wilt on hot, sunny days then recover overnight. If left alone, eventually the plants suddenly and completely collapse. The most startling symptom of a squash borer infestation is seeing healthy vigorous vines one day then seemingly the next day they are collapsed, wilted and dying.

I would hate to lose my squash vine at this point.
I would hate to lose my squash vine at this point.

You can help your vines minimize borer damage by taking advantage of  vine growth habits. You’ve probably noticed that squash and  other vines sometimes root themselves further away from the base of the plant. Those roots are actually functional and contribute to the vines growth. By encouraging rooting along different places along the vine, you can minimize the damage the borers do since the vine can get still get water and nutrients from the soil because of the extended root system. If the plant had to depend only on the roots at the base, no water would be able to reach those parts of the vine past the area damaged by the borer.

Rooting happens at the nodes.
Rooting happens at the nodes.

Rooting takes place at the nodes of the vine; those swollen spots on the vine from where the leaves grow. To encourage rooting, cover several nodes with a shovelful of garden soil. The secondary roots that form will support the plant even if the primary vine is destroyed by borers.

Bob

Local lacewings in your garden

While inspecting my garden today I ran across some very cool looking structures on the underside of a leaf. I could tell immediately that they were lacewing eggs. The thin stalks, each holding up a tiny white egg on its end, was the giveaway.

Lacewing eggs are held up on tiny stalks about 1/4" to 3/8" tall.
Lacewing eggs are held up on tiny stalks about 1/4″ to 3/8″ tall.

Lacewings are a good ally to have in your war against insect pests because they are a major predator of aphids and other soft-bodied insects like mealy bug, mites and even small, newly hatched caterpillars among others.

It is the larva stage of the lacewing that terrorizes the other small insects, especially aphids.

If left alone, aphids can rapidly overwhelm a plant by sucking the juice out of a plant's leaves and stems.
If left alone, aphids can rapidly overwhelm a plant by sucking the juice out of a plant’s leaves and stems.

Lacewings eat so many aphids that entomologists have nick-named them “aphid lions”. A single lacewing larva can eat over 200 aphids a week. The adult on the other hand, eats only nectar and pollen.

Depending on the weather conditions, the lacewings will stay in the larval stage for about two to three weeks devouring small insects all the while. When the time is right, they then spin a cocoon and emerge five days later as an adult. The adults mate and the females lay their eggs on the underside of a leaf or other sheltered spot. About four or five days later the eggs hatch and the cycle starts over again.

Watch for lacewing eggs on your plants and avoid spraying insecticide when you find them. Let them do their work and they will reward you by building up their population and eating even more insect pests.

Bob

Look out for cabbage worms

Earlier this week I spotted some small, white butterflies flitting around in our garden.  They were the easy to recognize adult stage of the imported cabbage worm larva. Now, a few days later,their larvae are voraciously eating our cabbage.

Typical signs of cabbage worm infestation: holes in the leaves and caterpillar droppings called "frass".
Typical signs of cabbage worm infestation: holes in the leaves and caterpillar droppings called “frass”.

Curiously, I haven’t seen any on the broccoli or kale yet, but they will show up there soon too. These pests eat any and all plants in the cabbage family including broccoli, cauliflower, kale, turnip and rutabaga. They are said to attack radishes as well but I’ve never seen it in all my years of gardening. Maybe it’s because our local population would rather eat the other plants if given the choice.

BTW, it’s not the baby caterpillar that makes the choice what to eat, it is its mother. The female butterfly flies all around looking for the ideal spot to lay her eggs so her offspring have the best food to eat. That way they can grow up to be big and strong and healthy. That is good for the cabbage worms but can be disastrous for a garden.

Farmers know that within days a few cabbage worms can chew so many holes into a cabbage that it will be unfit for market. Even in a home garden cabbage worms will ruin large portions of a cabbage.

There are a couple of different species of cabbage worms in our area, one is the imported cabbage worm, the other is the cabbage looper. They are both green and color and do the same damage. Imported cabbage worms are very slow and sluggish when they move. Cabbage loopers move along like inch worms.

If left alone, this young imported cabbage worm will quickly grow and cause lots of damage.
If left alone, this young imported cabbage worm will quickly grow and cause lots of damage.

Both species of cabbage worm are easily controlled by insecticides labeled for chewing insects on vegetables. Bacillus thuringiensis, or Bt, is a favorite worm killer among organic gardeners. It is made up of spores from a bacteria that infects only caterpillars and is harmless to other insects.

Controlling them now while they are still small is much easier than waiting until they get bigger and really start chewing away large chunks of your crop.

Bob

Join the Million Pollinator Challenge

While you’re deciding on what plants to add to your garden and landscape this year, think about pollinator friendly plants. By now most gardeners are aware of the steady decline in the number of pollinators over the past several decades. Bees, butterflies, moths, beetles and other pollinators have all taken a hit.

A large percentage of the foods we eat, over thirty percent, depends on pollinators. Plus, add to that, all of the different wild plants that depend on pollinators and you can see why it is such a problem. Even the federal government has acknowledged it be a matter of national security.

Planting even a few pollinator friendly plants in a garden will help, however more is better in this case.

Even though the situation is serious for pollinators, helping them doesn’t have to be a drag. The National Pollinator Garden Network has come up with a fun way to help us help pollinators. It’s called the Million Pollinator Garden Challenge. The organization hopes to register one million gardens, both existing and new,  that are pollinator friendly.

They suggest six simple to understand guidelines to help you with your pollenator garden. And if you want to take it to the next step, their website has loads of information to guide you.

Our own Michigan State University has been scientifically studying the pollinator decline and has a wonderful website tailored to the three general ecosystems in our state: Southern Lower Peninsula; Northern Lower Peninsula; and Upper Peninsula.

When you register with the Million Pollinator Garden Challenge, your garden site is pinned to a map of North America. It’s fascinating to see all of those pins on that map and where the gardens are.

Our area of southeastern Michigan looks under represented to me. I’m not sure if it’s because of a lack of gardens or if it’s because gardeners are unaware of the program.

Let’s make our gardens pollinator friendly this year, get pinned on the map and show the world how much our region cares about helping pollinators.

Bob

Help monarch butterflies by encouraging milkweeds

It wasn’t your imagination, there really were more Monarch butterflies this fall and it wasn’t just because we were looking for them anymore than usual. The folks at Monarch Watch have evidence that the monarch migration is shaping up to be somewhat larger this year than last.

As more gardeners and homeowners become aware of the importance of milkweeds and start encouraging the plants instead of eradicating them, the monarch butterfly population should rise in proportion.

One statistic I saw was that there are 113 million gardeners in the USA. Now just think for a minute if each gardener added only one or two milkweed plants in their yards how many more places there would be for monarchs to grow and develop.

In a few growing seasons, a single milkweed plant can quickly turn into a sizable local population.  Like so many other “weeds” milkweeds produce a lot of seeds. In my yard I counted about 80 seeds in just one milkweed pod. That small plant had seven or eight  pods growing on it. That’s around 500 seeds per milkweed plant. In more fertile locations, a milkweed plant can produce 20 pods that contain over 400 seeds in each pod!

Milkweed seeds grow in rows inside the pod.
Milkweed seeds grow in rows inside the pod.

Collecting and planting seeds is the best option for propagating milkweed. Just keep in mind that milkweed seeds require a cold treatment  — called stratification — before they will germinate. In the wild this occurs naturally each winter as temperatures drop below freezing. The easiest way to provide the cold treatment is to plant them directly into the soil in the fall and let nature provide the stratification.

Milkweed plants are perennials, meaning once they establish themselves, they will continue to come up year after year. Mature plants have roots that grow horizontally underground. They will send up a new shoot at intervals that grow into a new milkweed plant. So you can see how quickly milkweeds can get out of hand if you’re not careful.

I’ve had milkweeds pop up in my garden from roots sent out by plants many feet away. They can be very  persistent since a piece of root as small as an inch long can grow into a new plant.

Milkweed pods are just starting to open in southern Michigan. If you want to collect seeds, now’s the time to do it. Otherwise, soon the seeds will be gone with the wind.

Let the milkweed seeds fly or you can remove the silks and store the seeds in your refrigerator crisper until spring.
Let the milkweed seeds fly or you can remove the silks and store the seeds in your refrigerator crisper until spring.

As an extra bonus, you can spray paint your empty pods with gold paint and use them in craft projects just like we used to do in elementary school.

Bob

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.
IMG_3026
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.

Bob

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.

Bob

 

 

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.

Bob

 

 

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.

Bob

 

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.