Wednesday, September 30, 2015

A black-, orange- and white-checkered moth walked in...

...and decided to stay! Thus begins the story of the Ailanthus Webworm Moth and its excellent adventure. (This is a companion piece to an earlier post on the Common Buttonbush.) While Matty and I were sketching the Buttonbush flowers along the Little Miami River, we noticed a small black-, orange- and white-checkered insect was on a lot of the blossoms...

Orange-, black-, and white-checkered moths with long, thin beetle-like bodies were on many of the flowers at Spring Valley Wildlife Area.
Ailanthus Webworm Moths on a Buttonbush Inflorescence
These two dapper moths look like they are tiptoeing through the styles of each tiny flower. 

Ailanthus Webworm Moth
I'd seen the bug before, but had never studied it, so when we got home, I got out my "Kaufman Field Guide to Insects of North America," by Kenn Kaufman, and sure enough, there it was, an Ailanthus Webworm Moth (Atteva aurea), a day-flying moth that pollinates a lot of flowers as it visits them to sip nectar.

An Ailanthus Webworm Moth clings to the underside of a Swamp Milkweed flower along the Little Miami River near Spring Valley Wildlife Area. 

Tree of Heaven
This moth, which looks like a long skinny beetle when seen from a distance, is "sort of" a native to the United States (and here is where its excellent adventure kicks in). The lovely little moth got brave one day and jumped host plants. Originally, the moth was native to southern Florida and Central and South American, where its host plant, the Paradise Tree grew, but one day, it found a Tree of Heaven (Ailanthus altissima), which is closely related to the Paradise Tree, and decided to live on it. The Tree of Heaven is not native to the United States. It's from China, but it was introduced to the U.S. in the 1700s.  Since then, it has spread across the country, and the Ailanthus Webworm Moth moved along with it. (Click here for a detailed history of the Tree of Heaven in the United States and control strategies to prevent its spread.)


The Ailanthus Webworm Moth originally was native to southern Florida, but it followed the Tree of Heaven, an invasive introduced from China in the 1700s, as it spread across the nation.

The Tree of Heaven looks a lot like our native Staghorn Sumac (Rhus typhina), which produces seeds beneficial to the birds. There are several ways to tell the two trees apart. The easiest is the Tree of Heaven has smooth leaflets that turn yellow in autumn, while Staghorn Sumac has serrated leaves and turns bright red. Click here for an earlier post on Staghorn Sumac to see what it looks like in the fall, and learn about how it helps birds get through deep winter.  Click here for a pdf titled, "Invasives Strike Force Plant Guide, 2012," from the New York-New Jersey Trail Conference. This guide teaches you how to spot many invasive trees and tell them apart from native look-alikes.


An Ailanthus Webworm Moth, an early instar Monarch caterpillar, and a Monarch butterfly all share a Swamp Milkweed flower. The larvae of the Ailanthus Webworm Moth only eats Tree of Paradise leaves, but the adult moths are not picky and pollinate many types of flowers. 

One more thing...
The Tree of Heaven is famous for its starring role in "A Tree Grows in Brooklyn," by Betty Smith. Click here for a link to a critical essay on the symbols in the book, including the Tree of Paradise described in the first chapter, where the tree was a metaphor for all the immigrants coming into New York City during the 1700s and 1800s.


Additional references
For more information on the Ailanthus Webworm Moth, click here for "Moths of Ohio Field Guide," by David J. Horn, Ph.D; Ohio Department of Natural Resources, Division of Wildlife, or here for an interesting post on the blog "MOBugs; Missouri's Majority."

(I really enjoyed spending the day sketching with Matty (8-7-2015) at the Spring Valley Wildlife Area. Getting out in the wild with pencil and paper is relaxing and helps cement memories. The next day, I drove out with my camera to get photos. Beauty was everywhere...)

Saturday, September 26, 2015

A ping pong ball with wings...

...describes our chubby little migration-ready Ruby-throated Hummingbird! Rick and I were sitting on the deck yesterday evening eating our dinner when I looked up into a tree about 30 feet away and noticed what looked like a ping pong ball with wings resting among the leaves. I looked again and pointed him out to Rick. It was a fat little hummer ready for his big flight south...

This little hummingbird had been working hard to "enrich" his fat cells for his mighty trip south!
Hummingbirds need to double their weight to make the arduous trip safely. 

Our "house-hummers" flew the coop on Thursday, September 17 (it was a sad day). Hummingbirds migrate during the day, and ours must have taken off late in the morning, because we didn't see any the rest of the day, Friday or Saturday, but by Sunday afternoon, a new visitor had moved in (jubilation). He was a small and skittish juvenile Ruby-throated Hummingbird from the north, dropping in to fuel up for the next leg of his journey. We were used to our house-hummers who didn't mind our comings and goings and would hover inches from my face and hands as I changed the nectar in the feeders, but with our new visitor, if I even blinked, he would fly away. I texted my friend, Cheri, who lives a few houses up, and told her to watch her feeder. Maybe he was on his way to her. Within minutes, Cheri texted back that he was there! Then she would "blink," and he would take off in a huff for our house. Cheri and I texted back and forth that day while he ping-ponged between our feeders (and the huge trumpet honeysuckle vine that grows near our feeders). It was fun being able to predict his arrival. The next day, two more hummers dropped in, then another, then another. We appear to be a refueling and weight-gaining station for hummingbirds from the north as they wing their way south. I will keep my feeders stocked for a while, hoping to wring out the season as along as I can. The chatter of hummingbird-speak makes me happy, and getting to watch (and help out) hummingbirds migrating south is fun.

...yes, you're such a sweet little ping pong ball with wings!

If it were cold and he was fluffing up to stay warm, this fellow would look normal, but it was warm, and he was not fluffing up at all. He had gained the weight he needed to help him on his way south. I will watch for him today, but I bet he took off with the sun this morning. 

Hummingbird migration...
I've had three or four friends in the past couple of weeks as me how long they should keep their hummingbird feeders up. They don't want to impede their hummers' departure during fall migration. I always tell them, don't worry, a stocked feeder will not entice a hummingbird to stay longer than it should, but it might help a northern hummer on its flight south. Hummingbirds get itchy and jumpy when its time for them to migrate. They have an inner urge that drives them to leave triggered by the "intensity of daylight." As the days get shorter, hormones are released to increase their appetites so they can gain enough weight for their incredible journey south (from Mexico to Central America, as far south as Panama).

Hummers do not migrate in a flock, but they do fly out on favorable winds, so if there are many on the move, you might see several in a day. They usually fly during the day and sleep at night, except when they cross over the Gulf of Mexico. Hummingbirds fly low over the water, and it can take them 18-22 hours to cross. They can't sleep during this dangerous part of their journey and must have adequate fat reserves to fuel them across. Every time I think of these tiny little power houses winging low over the water my heart melts. Hummers are mighty birds! When hummers stop to rest along their journey, they may stay as short as one day, or as long as two weeks. I didn't know this, but I recently read when hummingbirds migrate, they fly low to the ground, just over treetops, so they can easily find nectar sources.

References
Click here for hummingbird migration details on the "World of Hummingbirds" website.
Click here for hummingbird FAQs on the "Hummingbird Journey North" website.
Click here for hummingbird migration basics on the "Hummingbirds.net" website.
A nice reference book is "Hummingbirds and Butterflies," by Bill Thompson III and Connie Toops.

Tuesday, September 22, 2015

Common Buttonbush along the Little Miami River...

A few weeks ago Matty and I went up to Spring Valley Wildlife Area along the Little Miami River with our sketchbooks. We spent the afternoon rambling about, sketching whatever we saw. When we came across a stand of Common Buttonbush (Cephalanthus occidentalis), we stopped and studied the tree and its blossoms, noting that the leaves occurred in whorls of three, and the "honey bell" was made of hundreds of tiny blossoms...

A Buttonbush inflorescence is a grouping of small flowers. The projecting needle-like styles create the starburst.
Common Buttonbush flower ball, also called a honey bell, dangles from a stem and looks a lot like a firework display, a starburst...or in a less romantic view, a pin cushion! 

Common Buttonbush is native to Ohio. It loves water and swampy areas, and true to form, we found a large colony hugging the edge of the lake and another in a low boggy area beside the lake, just steps from the Little Miami River. The flower balls were intensely fragrant, which is where it gets its nickname "honey bell" or "honey-ball," and butterflies were everywhere...

A female dark morph Eastern Tiger Swallowtail (Papilio glaucus) nectars on a Buttonbush flower-ball (inflorescence). The butterfly uses its proboscis to sip nectar from each tiny perfect flower and pollinates the florets in the process. 

Silver-spotted Skippers and Tiger Swallowtails were all over these flowers.
Two Silver-spotted Skippers (Epargyreus clarus) cling to the pin cushion for a sip of nectar as well. The long, projecting styles of each perfect flower in the inflorescence create the pin-like, starburst look.

The cranberry red stems of a Common Buttonbush shrub are almost as striking as its flowers. Its leaves have both a three-stemmed whorled arrangement (often near the flower) and an opposite arrangement elsewhere on the shrub.

Before the inflorescence bursts open, the tiny flowers (florets) are encased in tight mint-green buds (sepals). Here the flowers are just starting to open, but you can still see remnants of some of the buds and the light-green color.

After the flower petals have fallen away, little ball-shaped seed heads remain. Some will hold on through the autumn and winter. Each tiny flower in the inflorescence produces two seeds called nutlets. Often buttonbush trees grow at the edge of ponds, lakes, streams and rivers (or even in the water), so when the nutlets ripen and tumble out, they float and are dispersed by the currents. Wood Ducks, Mallards, teal, and other waterfowl like to eat the nutlets.  

For more information on the Common Buttonbush, including its historical use as a quinine substitute for malaria, look in "The Book of Swamp and Bog; Trees, Shrubs, and Wildflowers of Eastern Freshwater Wetlands," by John Eastman, pgs 34-37. For an online resource, click here for a link to The Hilton Pond Center's website, or here for the Ohio Department of Natural Resources Division of Forestry website.

What is an inflorescence?
When you look closely at a Buttonbush flower you'll notice it's a collection of hundreds of tiny flowers, called florets. Each one of the florets in the collection is a "perfect flower," which means it has a pistil (stigma, style and ovary) and stamens (anther and filament). The collection or grouping of florets is called an inflorescence. Common flowers with inflorescences are sunflowers and all the flowers in the daisy family. Click here for a past post called "Hummingbirds and sunflowers" that describes an inflorescence in more detail.


Tuesday, September 15, 2015

To attract Cedar Waxwings to your yard, let the pokeweed run wild...

The dark purple-blue berries of Common Pokeweed (Phytolacca americana) are irresistible to Cedar Waxwings. So much so that I don't even have to look out the window to know when they start to ripen. As soon as I hear the high-pitched, magical chittering of a flock of Cedar Waxwings in our backyard, I know the pokeberries are in season...

Pokeweed berries are nutritious for birds. Their dark color and beautiful light purple stems are attractive in the garden as well.
Common Pokeberries are ready for plucking and eating (by birds only; pokeweed berries are poisonous and can make humans sick). As soon as the berries are ripe, Cedar Waxwings descend and start feasting.  

These photos are from August 5 when most of the berries were not yet ripe. It was the beginning of their fruiting season, but it didn't stop the Cedar Waxwings from moving in. They knew exactly where every ripe berry was and wasted no time taking advantage of the nutritious summer treat. Now, the established plants are mostly picked over, but younger plants growing beside their elders are dripping with the dark, plump berries. In the wild, pokeweed plants look common, but in the suburbs, they look intensely exotic. Their cranberry red stems and racemes create an exciting backdrop to the dark blue fruit, and as autumn progresses, the colors only intensify. Our first stand of pokeweed started as a volunteer in 2008. At first I didn't know what it was, so I just let it grow, and did it ever grow. It grew tall and wide and arching, and soon it was dripping with chartreuse berries, but when they started to ripen, the fun really began. The first birds to eat the dark berries were robins, then came catbirds, and finally Cedar Waxwings. Over the years the catbirds still come, and the robins do too, but the Cedar Waxwings are the biggest consumer. I have a lot of pokeweed plants scattered around my yard, so I hear their chittery, magical sounds all summer.

A Cedar Waxwing looks for ripe berries. (There are two birds in this photo...can you see the second bird at the bottom near the right.) These two birds are part of a flock of 6 birds that regularly forage in our backyard. Earlier in the season, they feasted on mulberries from our 6 mulberry trees. 

A Cedar Waxwing swallows a pokeweed berry whole. You can see the bird's gular pouch distending to hold the berry (click here to learn more about gular pouches). 

If Thoreau liked pokeweed...
...it has to be good, right? I was reading "The Book of Field and Roadside; Open-country Weeds, Trees, and Wildflowers of Eastern North American," by John Eastman, and came across a reference to Thoreau where he wrote, "its stems are more beautiful than most flowers," which is true. You can't walk past the plant without taking a second look. I wanted to see what else Thoreau said about pokeweed, so I looked up the passage and found it in "The Writings of Henry Davide Thoreau, Volume 10," page 393. Click here for the online link to the free ebook. He goes on to describe them in detail as only Thoreau can, ending with "It is a royal plant. I could spend the evening of the year musing amid the poke stems."  

Pokeweed has a wide spreading habit. This is just one plant (and it's only half of it!). Pokeweed grows 4-10 feet tall, and its berries can remain viable for 40 years. 

Pretty to look at, but leave the berries for the birds (all parts of a pokeweed plant are toxic to humans). 

Pokeweed is a poisonous plant...
If you have children, pokeweed might not be a good plant for your yard. The roots are the most poisonous, followed by the leaves and stems, and then the berries. Children can be sickened by eating as few as 10 berries. Babies are especially vulnerable to the toxins and can die after eating only a few berries. The roots are deadly, and you should wear gloves if pulling the plant while it's alive (the juices can harm the skin). To learn more about pokeweed, click here for The Ohio State University's "Ohio Perennial and Biennial Weed Guide."

Mulberries attract Cedar Waxwings too...
In late May and Early June the mulberries in our yard start to ripen, and they are the first berries to welcome back the waxwings, but their season is short, and by July, they are gone, which makes pokeweed so perfect. It lures the Cedar Waxwings back in, and we get to listen to them all the way through the end of summer and early autumn.

A Cedar Waxwing sits in one of our mulberry trees. He's not looking for fruit in the tree. It's been gone for a long time. He's looking at the pokeweed bushes near the tree...

Thursday, September 3, 2015

Busy little caterpillar, eat, eat, eat...

As a prequel to the previous post of the monarch chrysalis and the butterfly's first flight, I thought it would be nice to look closely at a monarch larva. I was able to use my macro lens to get a closeup of a monarch caterpillar (5th instar) chomping its way through a milkweed leaf. It gives you a good idea of how fast a larva can devour a leaf, and just how much it eats (practically nonstop) to be able to grow so quickly and move through 5 instars...



When the larva is ready to molt, it becomes very still and latches itself to a leaf with silk it produces from a spinneret located on its lower lip. The head capsule is the first to molt, and the cuticle (outer skin) then splits down the back. Below you can see the caterpillar just after it escaped from its cuticle (the grey mass behind it). It has now moved into its fifth instar. You can tell which instar a monarch larva is in by the size and shape of its tentacles. To learn more about monarch larva and instars, click here for a pdf version of "A Field Guide to Monarch Caterpillars (Danaus plexippus)," by Karen Oberhauser and Krista Kuda, or here for the monarch life cycle on the University of Minnesota's website. 

Our monarch caterpillar has just molted into its 5th instar. You can see the thin, crumbled cuticle behind it. 

In the following video, you can see the very end of the caterpillar shedding its skin. The quality isn't great, because I took it with a cell phone instead of my camera, but you get the idea... 


Monarch caterpillar shedding its cuticle (outer layer of skin) from Kelly Riccetti on Vimeo.


Where is its head?
At first it's a little hard to tell the front end from the back end of a monarch caterpillar. Both ends have black fleshy tentacles that resemble antennae, but when you look a little closer, it's easy to tell the difference. First look at the tentacles. The front pair are much longer than the back pair. The front tentacles function as sense organs similar to antennae, but the back pair are thought to be defensive to confuse predators on which end is the head. Second, look at the legs. Three pairs of jointed "true legs" are in the front. Five pairs of "false legs" (prolegs) are attached to the abdomen all the way to its rear. 

The monarch caterpillar's larger tentacles are near its head. Three pairs of jointed true legs are on the thorax near the head as well. In the photo above, the head is on the right (you can't see the third set of true legs).

What's the difference between true legs and prolegs?
Caterpillars have three pairs of true legs attached to the thorax. These legs are segmented and often have a claw on the end. They help the caterpillar hold its food. If you look closely in the photo below, you can see the tiny claws at the tips of the true legs on the monarch caterpillar. True legs transform into the legs of the adult insect during metamorphosis. Caterpillars also have prolegs attached to the abdominal segments, but the number of pairs varies among species (monarch caterpillars always have five pairs). Prolegs are stumpy, cylindrical, and unsegmented. They also have microscopic hooks at their tips that work like suction cups to help the caterpillar cling to stems and leaves. The prolegs dissolve during metamorphosis.

In this close-up you can see why monarch tentacles are always described as "fleshy." They are not segmented like an adult insect's antennae, they are fleshy. You can also see a close-up of the three segmented true legs on the thorax.


Cuteness! A monarch caterpillar was underneath the leaf munching away, then another crawled over the top and started to eat as well. When the two "met in the middle," they touched heads, looking a little smoochy-smoochy. The caterpillar underneath shook its head and moved to the other side of the midrib of the leaf. No time for that...must eat more milkweed leaves!