Shady Ladies

A walk up a wooded hill on a recent sunny day brought beauty — pale blue clematis, twining around the base of an aspen.

They love shaded woods, trailing along the ground or winding gently up a tree trunk, each flower upright on a tall stalk. The four-pointed blossom is pale blue verging on mauve.

Clematis belongs to the buttercup family (Ranunculaceae) which includes many familiar flowers, among them anemones, columbines, larkspurs, crocuses and, of course, buttercups.

Even when clematis go to seed they are lovely, forming silvery plume-like clusters. Another walk up the hill is warranted soon.

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Blue clematis   Clematis verticellaris var. columbiana

Sapsucker Sap Wells

 

Okay, say that title 5 times without tripping over your tongue.

Sapsuckers do, indeed, suck sap. It’s their main food source, though they also dine on insects, especially ones attracted to sap.

Sap wells are the holes that yellow-bellied sapsuckers drill into live trees. Once you’ve seen sap wells, you can’t mistake the lines of organized holes for anything else.

In the spring sapsuckers drill deep round holes (into the tree’s xylem for the botanically inclined) to catch the sap rising from the roots up to the branches.

Later, after the tree has leafed out, they drill shallow, rectangular holes (into the phloem) to catch the sap being sent down the tree to be stored in the roots.

Yellow-bellied sapsuckers are frequent visitors to our yard. For years they have dined on the sap from lilac, saskatoon and mountain ash.

Even from a distance it’s possible to spot a sap-stained tree trunk.

The lilac still blooms each year, despite the havoc heaped on some of its trunks.

The saskatoon bush has also seen lots of sapsucker activity.

Recent holes on the mountain ash (the yellowy orange ones) along with the work of years past.

This year, for the first time, I caught a sapsucker family feeding on a large aspen.

This year’s young

Male, with red head and red throat. Females lack the red throat patch.

The long vertical white wing bar is a distinguishing feature of yellow-bellied sapsuckers

Search YouTube if you’d like to see these suckers in action. 🙂

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Yellow-bellied sapsucker   Sphyrapicus varius
Aspen   Populus tremuloides

Egg Case

The Tortrix moth infestation that occurred this spring was of almost biblical proportions. Many of the aspen forests were completely denuded by the ravenous caterpillars (aka larvae).

They pupated next, then after a short respite, the adult moths appeared. Thousands of them. And of course, their main goal was mating and egg laying, which they did in grand fashion.

In fact, so intense was the drive to lay eggs, they did so in the most unusual places. We discovered egg cases, like the one above, on the windows of the house, on the siding and on the vehicles.

Many of these eggs never hatched. The ones on the south-facing windows, for example, simply got too hot. But not before some activity occurred.

The egg cases were all about the same size as this one — 1.3 cm or so long (0.5 in). The original egg case was a lime green — some of that is still visible. I’m assuming it was plant material to feed the newly hatched larvae.

The comma-shaped figures are the newly hatched black-headed larvae. Some of the cells are empty — perhaps they survived?

Mother Nature’s Natural History Show is a wonder. Glad I caught this episode.

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Large aspen tortrix   Choristoneura conflictana

Here’s Lookin’ At You, Kid

I don’t get to see the underside of life very often. Bugs and butterflies don’t take kindly to being upended.

Finding this large aspen tortrix moth on my window was a perfect opportunity to check out the undercarriage. Quite different from the bland topside view — this is right out of a sci/fi movie.

This spring its larvae devastated huge swaths of aspen poplar, eating all the leaves until limbs and twigs were bare. Their silk festooned the woods, draping over everything below, right down to the forest floor.

The trees are slowly recovering and the moths are disappearing. Cycles within cycles.

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Large aspen tortrix   Choristoneura conflictana

The Silk Makers

I wrote recently about The Silk Road. This is the rest of the story.

How many mouths does it take to eat a tree?  Not the wood. Just the leaves. All of them.

That’s what has happened in our corner of the world. Most of the aspen poplar have been completely defoliated by armies of small black caterpillars.

The caterpillars, or larvae, are the second stage in the life cycle of the Large Aspen Tortrix.  The name Tortrix comes from a Latin word meaning to twist. When you see the leaves they’ve been feeding on, you can see why that name was chosen.

These photos and captions tell more of this tale …

Aspen defoliated by caterpillars of the Large Aspen Tortrix. The other leafy trees are balsam poplar which are mostly unaffected.

The start of the infestation — larvae have eaten much of the leaves.

Larva on a spruce branch. Strong winds and the search for more food sent larvae groundward on strands of silk. This one landed on a spruce tree.

Larvae that weren’t able to find poplar leaves to pupate in settled for spruce.

Tortrix larva beginning to spin silk on a poplar leaf in readiness for the next stage in its life cycle.

This larva is spinning silk on a balsam poplar leaf, drawing the leaf sides closer together until it is completely hidden. It will hide there, turning from an active leaf-eating caterpillar into a non-feeding pupa, the next stage in its life cycle.

Here’s an interesting grouping (L to R): a fully formed pupa, the larval skin it shed as it pupated, and a caterpillar beginning its transformation.

Some pupae have already split open, releasing the adult moths. I imagine we’re in for quite a show when the big hatch happens.

We’ve had defoliations in the past, but I don’t recall anything like this — it stretches for kilometres in all directions.

Although this feeding frenzy sounds disastrous for the aspens, it’s not as gloomy as one might expect. The trees are already sprouting new leaves and before long will look more like they should at this time of year.

Conditions this year are different. Winter was mild. Spring came early. It turned hot. Rainfall has been little and sporadic. Are we seeing the effect of climate change? Or merely a brief climatic blip?

It’s an ongoing evolutionary dance as we each strive to adapt to our world.

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Large aspen tortrix   Choristoneura conflictana
White spruce   Picea glauca
Trembling aspen   Populus tremuloides

 

It’s Not a Perfect World

The aspen leaves, barely unfurled, are already facing a barrage of bugs and worms intent on eating them alive.

But the aspens — and most of their leaves — are still here.

They’ve done this dance before.

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Trembling aspen   Populus tremuloides