Sunday, September 25, 2016

Back From The Dead

This year seemed to be a very “good” year for tent caterpillars. I had more people remark on seeing them than ever before. The caterpillars (or rather the parent moths) seemed especially fond of sourwood (Oxydendrum arboreum) and persimmon (Diospyros virginiana) trees this year. As is my way, I left the trees alone to let nature run its course.

Tent caterpillars on sourwood

The small persimmon next to the street light was 100% engulfed and surely looked fit for a Halloween decoration by the time the caterpillars were done with it. Nearby, several medium sourwoods looked like something out of a Dr. Seuss story, with large pompom-like nests on the branches. I know that the neat-nik neighbors down the street must have been horrified every time they drove past.

Datana caterpillars finish off the leaves

One sourwood in the back was doubly cursed. The leaves not eaten by the tent caterpillars were consumed by a different species until nothing but the thin leaf veins were hanging in wispy groups. I was truly concerned for this tree. Could it possibly survive such devastation? 

While the caterpillars themselves don’t kill the tree, without the leaves to gather sunlight and make nourishment for the roots, the tree might actually perish.

New leaves beside remnants of the eaten ones

I am happy to report that all the affected trees, including the one in the back, have started to put out new leaves. We might even get some decent fall color on these trees (sourwoods have awesome fall color when they have leaves).

So if you ever wondered what happens to trees with tent caterpillars … now you know they can make it just fine!

Sunday, September 18, 2016

Roadsides: Trash or Treasure?

I think about roadsides a lot this time of year and there are several reasons why. 1) Sunny roadsides with good native plant populations really shine this time of year. 2) Roadsides that got whacked by utility contractors are really ugly this time of year. 3) Roadsides that are overgrown with invasive plants are at their tangled peak by now. I wonder what other people think. Do they look at roadsides and see trash or do they see treasure? The answer, I think, lies in how much they know about what they see.

You see roadsides can be full of trash or treasure. It depends on how they are treated, and humans play an important role in what’s there or what’s missing. What would make a roadside be considered trash vs. treasure?

You probably won’t be surprised to learn that the distinction lies in the type of plants that reside there. A roadside with native plants tips toward the treasure end of the spectrum. How far along the spectrum it is depends on what kind of native plants are there. A roadside rich in a diverse mix of native plants is desirable compared to one that is composed of just a few types. For example, a roadside composed of all one type of tree (for example, pine trees) won’t support as many insects and birds as one with a dozen different plants. If that diverse mix includes flowering plants across several seasons, the treasure score goes even higher.

Small residential area with part lawn and part wild roadside
A good roadside is a sunny strip that might be bordered by a bit of a tree line with 2 or more different kinds of native trees and shrubs. It would include some rambunctious annuals, some biennials and a few perennials as well. In my area that might be daisy fleabane (Erigeron), black-eyed Susans (Rudbeckia), thistles (Cirsium), goldenrod (Solidago), thoroughwort (Eupatorium), milkweeds (Asclepias), ironweed (Vernonia), sunflower (Helianthus), and native grasses. The tree line has sweetgum, oak, pine, sassafras, sourwood, tuliptree, muscadine, and maples.

A wet ditch roadside might have wingstem (Verbesina) and ironweed (Vernonia)

At the trash end of the spectrum is the roadside choked with non-native plants. The very worse (at least to humans) might be one smothered in kudzu. However, it doesn’t even have to look that obvious to be a place that offers very little sustenance to our native insects and birds. (A roadside composed of crape myrtles and Bermuda grass would do the trick, and surprisingly, these types of manicured roadsides are being installed more often around interstate exchanges – imagine the maintenance!) Usually, roadsides are havens for non-native plant seeds to settle and take root, free of most human intervention to dislodge them (until they get in the way of a utility).

Roadside in 2014 with pears moving in; 2 years later it is thick as a jungle
A trashy roadside has non-native grass, lespedeza, mimosa, tree of heaven, princess tree, elaeagnus, privet, Queen Anne’s lace, non-native thistles, and vines like kudzu, Japanese honeysuckle, porcelainberry, and English ivy. It’s roadsides like this that give roadsides a bad name! They become overgrown with invasive plants, untended except by utility contractors and road crews anxious to get the job done and be gone (bush hogs are popular brush management tools in my area).

English ivy chokes both the trees and the ground

How can we have better roadsides? In general, I would recommend four concepts to foster more productive roadsides:

  • Protect roadsides that already provide good native plants
  • Manage roadsides for invasive plant removal and annual mowing and maintenance if needed
  • Create roadside habitat by seeding degraded areas with native seeds/plants
  • Educate people on why roadsides and edges can help local insects and birds if native plants are present
Imagine that road crews might be instructed to identify and remove the top 5-10 invasive woody plants rather than just hack them back (only to have them return with a renewed vigor). People could reseed disturbed areas with native seeds, instead of non-natives, and with plants chosen for low maintenance even while they support the local insects. People would use the power of the Internet to identify what plants are and decide to keep them or not!

So, are roadsides trash or treasure? The answer is both – for now. How long will that last, until all we have is trash? Let’s invest in developing more treasure. As more and more of our land turns to developed spaces, the roadsides are some of our last sources of food for insects, birds and small critters that live around us.

Sunday, September 11, 2016

Useful Eupatoriums

Have you seen the plants with a haze of white flowers on the roadsides lately?  Many of them are 3-5 feet tall, thriving in both dry and wet ditches, holding their own against non-native weeds.  Small, individual flowers come together on flowerheads, which then combine together to form a larger inflorescence. The appearance of these inflorescences is as almost-flat clusters that together span the width of the plant. This is late thoroughwort, Eupatorium serotinum.

Eupatorium serotinum feeds a lot of insects

Eupatorium serotinum

This species and many others in the Eupatorium genus are late summer bastions of nectar and pollen for a variety of insects. Eupatorium is a member of the Aster family (Asteraceae) so it has many small flowers arranged on a flowerhead. Unlike what you might think of as an aster, these plants only have the non-showy disk flowers (the classic aster flower that you might envision has inner disk flowers and surrounding ray flowers).

I actually have quite a few species in my garden –  as many as 5 different ones. As I’ve been thinking about this post, I’ve been watching them, for this is the week that they have exploded into bloom. The insect community that uses them varies over the course of the day, and it’s an amazing parade to watch.

Eupatorium rotoundifolium

Morning visitors are the bees that spent the night on the flowers and who are just now waking up. There might be a few leftover moths as well, but generally, morning is the quietest time.

In the afternoon, fragrance emerges in the warmth of the day and it’s the busiest time. I see bees of all sizes, from the small green bees to the energetic medium-sized bumblebees to the largest carpenter bees (dragging down every stem they touch). I see flies like syrphid flies and bottle flies. Wasps love it too and there are at least a dozen species that visit!  

Small green bee

Carpenter bees are a bit big for this
Bumblebees are just right

Of course, we all love the Lepidoptera and, during the daytime, the tiny ones rule! A couple of red-banded hairstreaks have been constant visitors while an Eastern tailed-blue has stopped by several times as well. Skippers and common buckeyes also enjoy it when they’re in the area as well as American lady butterflies and other medium-sized ones. The flowers are too tiny for large butterflies like tiger swallowtails.

Red-banded Hairstreak
Eastern tailed-blue

It should come as no surprise that there are a few predators as well. Baby Carolina anoles patrol the inner stems for small bugs like mosquitos (yes, they visit too). I’ve also seen a couple of ambush bugs, carefully camouflaged and wedged between the flowers, and there are always spiders.

Carolina anole hunts
Green lynx spider on Eupatorium album

The flowers stay open all night so the moths continue to visit in the dark, their eyes shining like colored diamonds in the beam of the flashlight that I use to find them. It’s been fun checking on them at night and watching them slurp up nectar.

Actually a day-time moth (Desmia)

In addition to their flowers, Eupatorium members also serve as larval host plants for at least 42 different species of butterflies and moths. So if you’d like some late summer action in your garden, add some Eupatorium to it.

And don’t forget some of the former Eupatorium members like Joe pye weed (now Eutrochium) and blue mistflower (now Conoclinium). Even though they’ve been kicked out of the genus, they are popular with very similar insects.

Sunday, September 4, 2016

Caterpillar Tales

Acronicta tritona on blueberry
What a week it has been for caterpillars here! Or is it just a week in which I have become more observant? I’m sure they have quietly been here all along, but this week I was inspired to search for them and - once I started looking - there they were.

It started with a Facebook group – Caterpillar Identification of North America (originally for Eastern North America). With almost 3000 members, a lot of pictures get shared every day of recently found caterpillars. I thought to myself that I really needed to look around more here, for surely some of those could be here too.

Saddleback on goldenrod
So I braved the mosquitos and went outside after work and started looking. And they were there! For a string of several days, I was able to find a new one every day. On Sunday, I found 3 tiny saddleback caterpillars (Acharia stimulea) on goldenrod (Solidago erecta) in the garden – they are colorful but painful! I carefully relocated them to another goldenrod far away from the garden.

On Monday, I found the colorful hooded brown owlet moth nestled in a pot of ‘Golden Fleece’ goldenrod (Solidago sphacelata). I had always hoped to find one of these. It becomes a brown moth that I may never notice, but what a great caterpillar!

Cucullia convexipennis on goldenrod

Also on Monday, I found triton dagger moths on the blueberries. What a cool name! They were small and green when I found them, but some are reddish now as later instars. They are very modest eaters compared to some others.

On Tuesday, I was determined to check the redbud (Cercis canadensis), and I found something! This brown and green caterpillar turned out to be Schizura ipomoeae, the morning glory prominent moth.

Acronicta tritona on blueberry
Schizura ipomoeae on redbud

Excited about my daily treasure hunt, I went out Wednesday to check new types of trees. Near the driveway are several green ash trees (Fraxinus pennsylvanica). Looking up into the leaves, I spotted a brown blotch and realized it was a caterpillar - the hag moth (Phobetron pithecium). I pulled the leaf down to take pictures and have been fetching fresh ash leaves for it ever since.

Phobetron pithecium on ash - how nice!
Phobetron pithecium, the hag moth

Thursday was a bust, however, and I found nothing new. Despite thorough searches on oaks, I found only the usual yellow-striped oakworm this week.  I have found nothing so far on hickories or cherries at all. Of course, I am limited to searching at mostly eye level.

Actias luna on sweetgum

On Friday, I checked out sweetgum trees (Liquidambar styraiflua) and found a bright green luna moth caterpillar. I found only one and when I went back several hours later, it was nowhere to be found. I feel lucky to have found it the first time!

So if you've been wondering where the caterpillars are, get out there and find them. Apparently, they are quietly chewing all around us.