Insects « The Yellow Farmhouse Garden

November 14, 2019

Witch Hazel blooming in the snow

Filed under: Flowers,Insects,Shrubs,Weather — Tags: fall flowering shrubs, flowering shrubs, Late fall, owlet moth, Snow on flowers, Winter flowers, Witch Hazel — bob @ 5:08 pm

Even though the meteorologists had it in their forecasts, the recent big snow and cold temperatures still took us all by surprise. With normal highs in the low fifties and lows in the mid-thirties, some parts of the natural world were caught unprepared too.

I’m sure our witch hazel bush wasn’t expecting over a half-foot of snow and temperatures down in the single digits. Late fall is the normal blooming time for witch hazel. Sure enough, there it was, blooming in the middle of all that extreme weather.

We have our witch hazel planted near a window so we can enjoy its flowers indoors while looking outside.

In addition to flowering in November, witch hazel is kind of unusual for a native plant in that it has both seeds and flowers on its branches at the same time.

The seeds that are present this fall are from flowers that were pollinated last fall. They begin developing in late fall then over-winter on the plant. The following spring the seeds begin growing again and develop into a full-mature seed in the fall. Once the seeds are mature, they are ejected from their seed capsules with a pop! that sends them many feet away. It really is a fascinating plant.

One question you might have is,if witch hazel flowers in the fall when it’s cold outside, how are they pollinated ? All of the bees, wasps, flies, ants or other usual pollinators are not flying or dormant this time of year.

It turns out there are moths that stay active during freezing weather. These moths belong to the owlet moth family (Noctuidae). They fly at night looking for sources of nutrition such as tree sap. And it just so happens witch hazel nectar is a perfectly acceptable food for them. Just like bees, when the moths feed on the nectar, they also inadvertently move pollen around allowing pollination to occur.

We rarely see these moths because they fly at night. I remember back when I was a young kid, I once saw some moths flying in the cold weather. It struck me at that time as being pretty odd.

So did the early snow bury the owlet moths and prevent witch hazel pollination this year? Probably not, the witch hazel was blooming well before the snowstorm and probably were already pollinated by that time.

Bob

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September 19, 2019

Migrating monarch butterflies

Filed under: Butterflies,Flowers,Insects,Other Organisms — Tags: goldenrod, goldenrod butterflies, monarch butterfly, monarch butterfly migration, nectar — bob @ 10:39 am

In past years, goldenrod has received a bad reputation through no fault of its own. For decades, doctors implied their patient’s allergy symptoms were caused by goldenrod pollen when in fact, the actual culprit was ragweed.

The thinking behind it was ragweed flowers are relatively inconspicuous compared to flowers on other plants. Unless you’re really looking for it, ragweed can be hard to find. Goldenrod on the other hand, with its bright yellow flowers can easily be seen by a man on a fast horse. Since goldenrod blooms when ragweed is shedding pollen, it was simply easier to tell allergy sufferers to expect their symptoms to show up when goldenrod is out. Botanists would call this a phenological event. That’s when something goes on with one species of plant that is a signal for something else.

Goldenrod flowers produce large amounts of nectar so is always eagerly anticipated by beekeepers. A large goldenrod bloom can make the difference between no honey crop or a bountiful one. It is one of the last family of plants to remain blooming after others have stopped for the year.

Honeybees are not the only ones that take advantage of the nectar bounty. It’s an important fall food for wild pollinators and butterflies such as monarchs and other species.

Earlier this week we were sitting on our front porch taking a break and noticed some movement in our wildflowers. Looking closer, we could see over twenty adult monarch butterflies feeding on nectar from the goldenrod growing in our yard.

Look closely, how many monarch butterflies can you see?

Judging by what is happening in and around my stomping grounds, it looks like a good year for monarch butterflies.

The monarch migration is underway and coincides with the fall bird migration (and Michiganders heading back to Florida).

During our break we also watched a kettle of broad-winged hawks circling high in a thermal updraft. They were on their way south to their winter home. While watching the hawks, way up in the air we could see something passing by in and out of our field of vision through the binoculars. After re-focusing and zooming in on them, we discovered they were monarch butterflies!

More monarchs were flying just over the tree tops. It was a lot of fun watching them fly at those different altitudes instead of fluttering around the garden.

Pair of monarch butterflies mating in mid-September

There are still quite a few caterpillars feeding on our milkweed plants too. We even spotted a pair of mating adults. That seemed late to me. The eggs will have to hatch; the caterpillars have to pupate; and the adults emerge before the weather gets too inclement for them to fly south. I’m not sure if they’ll have enough time to complete their life cycle this fall.

Bob

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August 30, 2019

Striped cucumber beetles can devastate your crop

Filed under: Disease,Insects,Vegetables — Tags: bacterial wilt, cucumber beetle, cucumbers, identifying bacterial wilt, spotted cucumber beetles, stripped cucumber beetles — bob @ 8:12 am

The first striped cucumber beetles of the season have finally showed up in my garden. These bright and happily colored pests cause a lot of damage in the garden. Although cucumbers are their preferred food, melons are also attacked was well as squash and pumpkin to a lesser degree. At this time of the year, these are actually the second generation descended from those that were around earlier in the spring. I didn’t see those from the first generation in my garden but they must have been around in the neighborhood.

Cucumber beetles have a distinctive yellow color with black stripes.

Typical cucumber beetle feeding damage.

Adult beetles are a triple threat to cucumbers. First, the physical act of feeding by chewing holes in leaves reduces the leaf area stunting plant growth.

Secondly, they reduce the number of actual cucumbers by destroying flowers as they feed on them. Fewer flowers equals fewer cucumbers.

Cucumber beetles will eat flowers as well as leaves.

The third threat is the most damaging of all. In their gut is a bacteria that causes bacterial wilt, a very serious disease that can destroy a majority of a crop. As the beetles feed randomly over the surface of the leaves, eventually they will have to defecate. The feces contains large amounts of bacteria that will infect the plant if it is deposited over a chewed spot.

As you probably can guess from its name, bacterial wilt causes vines to suddenly wilt. Early on during the infection, vines will appear to recover somewhat overnight only to wilt again the next day as the day progress. The vines will eventually die in about seven to ten days — there is no cure. Remove any infected vines and compost them or discard them away from the garden.

Symptom of bacterial wilt on cucumbers.

One single beetle is enough to infect an entire plant so it’s important to kill the beetles as soon as you see them. There are conventional and organic insecticide sprays on the market that do a good job controlling them.

Plant breeders have developed cucumber varieties that are less attractive to beetles than regular varieties. Organic farmers will grow the one of the new varieties as their main crop. At the same time, they plant a more attractive variety in different spot to lure the beetles away from the main crop eliminating the need to spray the main crop.

If all that damage is not enough, as a bonus, the beetles will feed on the actual cucumbers themselves leaving behind feeding marks that disfigure the fruit.

Another species, the spotted cucumber beetle, also can show up. They are the same size and shape as the striped beetles but have black spots instead of stripes. They cause the same kind of damage and need to be controlled too.

Bob

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August 15, 2019

Michigan monarch butterflies and milkweeds up north

Filed under: Butterflies,Insects,Weeds — Tags: milkweed, milkweed leaves, monarch butterfly, monarch larva, monarchs, purple milkweed — bob @ 10:13 am

We’ve been spending time in northeast Michigan on and off for the past month or so. In one particular location, I noticed more Monarch butterflies this year than in the past.

A couple of weeks ago there were at least a dozen Monarch adult females frantically flying around from plant to plant laying eggs on a colony of milkweed plants. That lasted for a couple of days and was still going on when we left for home.

We returned earlier this week expecting to find caterpillars all over the place. The plants were still there but there were no caterpillars to be found anywhere. The only difference was the plants had bloomed and the blossoms were quickly fading.

These are a different species of milkweed than we have at home. The purple flowers with their distinctive scent along with a purple mid-vein on the leaves, plus other traits, told us these were purple milkweed, Asclepias purpurascens. At our home in southeastern Michigan we have mostly common milkweed, Asclepias syriaca.

There are several species of milkweed. This is purple milkweed.

I’m not sure why no caterpillars developed on the purple milkweed plants. It could be that predators ate the eggs before they hatched or ate the small caterpillars just as they emerged from their eggs.

On the other hand, this past weekend in the Caseville area, our daughter Robin and her cousins saw tons of caterpillars on milkweeds. Each and every plant, even the yellowing ones, had at least two caterpillars, others had even more. They didn’t know what species of milkweed those were since the plants hadn’t started blossoming yet. Adult females were quite busy laying eggs there too.

With that many caterpillars you expect to see evidence of predators and they did. While admiring a caterpillar up close, out of nowhere a predatory wasp zoomed in and dive bombed it. The caterpillar fell from the plant and was writhing wildly on the ground. When the spasming ceased, the hikers returned him to his roost on the milkweed. The hikers didn’t know it at the time, but the caterpillar was already doomed. The wasp had laid its eggs inside the caterpillar’s body making a nursery for a new generation of wasps.

We did eventually find a caterpillar on the purple milkweeds in the northeast location. We found it in a most unlikely spot. While we were hiking through a dense, shady cedar swamp with ferns, mushrooms, and jack-in-the-pulpits we came across a clearing where some trees were knocked over during a storm.

In the middle of that sunny clearing was a single purple milkweed plant that had one lonely monarch caterpillar that was nearly full grown.

An airborne milkweed seed landed in the middle of the woods and took root. Later a female butterfly found it and laid an egg.

Deep in this seemingly inhospitable environment, it was no place for a butterfly. It’s a wonder how the Mother Monarch found her way there at all.

Bob

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July 27, 2019

Remove fallen fruit from your orchard

Filed under: Fruit,Insects — Tags: apple pests, apple worm, Codling moth, codling moth larva, fallen apples, worm in an apple — bob @ 9:44 am

What’s worse than finding a worm in your apple? A: Finding half a worm.

Modern pesticides and strict inspection policies have made finding a codling moth larva, or worm in an apple from a supermarket’s produce department a pretty rare thing for most consumers. Even though kids nowadays have never had that experience, the friendly worm in an apple still is subject of children’s books and cartoons.

A codling moth larva crawling out of an apple — the proverbial worm in the apple.

Most backyard fruit growers on the other hand, have had direct experience with codling moth larvae. It’s one of the most common insect pests attacking apples and pears and if you let down your guard they will find your fruit and make a home in it.

Codling moths have a lifecycle similar to other moths. First, the adult female lays her eggs on the surface of an apple. Then the eggs hatch and the tiny larvae burrow into the fruit eating their way to the core. When fully grown, the larvae emerge from the fruit and find a protected area where they spin a cocoon and pupate. Early in the season they will emerge as new moths and lay more eggs.

Those present at the end of the season will spin a cocoon but will not pupate. Instead they overwinter as larvae inside their cocoon and pupate the following spring.

A regular spray schedule will keep these pests at bay but not everyone wants to use chemicals on their produce. In fact a major reason people have for growing their own fruit is to eliminate or reduce the amount of chemicals they may be exposed to. Sometimes a spray or two can missed, due to weather or other reasons, allowing the moths to gain a foothold.

Like most things in life, ignoring the problem will not make it go away. If you don’t want to spray, you’ll have to do some other things to reduce the number of worms.

The first is to pick any damaged fruit on the tree to keep the larva inside from completing their life cycle. Also pick up any fruit that falls. Codling moths are just as happy to live inside a fallen apple as one hanging on the tree. Dispose of these apples in a way that the larva are destroyed. I give mine to our chickens, they love those wormy apples. For them, the worm is a special treat inside!

Composting is usually not a good option for disposal because most backyard compost piles don’t get hot enough to destroy codling moth larva. Municipal composting on the other hand has no problem with them. So bag them up for city compost or put them in with your regular trash.

Codling moth females prefer to lay their eggs on the most protected spot on a fruit. This often is on the spot where two apples are touching each other. Removing one of the apples eliminates the “sweet spot” that egg laying females are looking for. It’s one of the reasons why you should thin fruit as your crop begins to develop.

While getting rid of infested fruit helps tremendously, it won’t completely eliminate codling moths. The can fly fairly long distances and may fly to your trees from surrounding areas where fruit is left to fall and codling moths emerge.

Other fruit pest such as apple maggot, oriental fruit moth and plum curculio also can be reduced by disposing of fallen fruit.

Bob

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