October 4, 2009
A COLD, SODDEN BUMBLEBEE
This week the hot dry season has suddenly snapped into the chilly rainy season. This weekend there was spotty frost in the area, and rain, with the snowfall line dropping ever lower in elevation. Tuesday with a temperature of 47°F (8.3°C), after a bone-chilling drizzle, I was wheel-barrowing leaf mulch into Anita's flower garden when I spotted the pitiful sight shown at http://www.backyardnature.net/n/09/091004bb.jpg.
A bumblebee lay atop a marigold flower sodden from the rain, not moving a hair even when I nudged her (worker bumblebees are female). In the picture, just inside the leg at the far left, you can even see the proboscis, her straw-like mouthpiece, extended downward into empty space, as if frozen in place by a sudden temperature drop.
I've often found bumblebees on flowers like this after a cold night. Are they dead, or just spending the night, planning to fly off when it warms up? I watched the bee throughout the morning and she didn't move. Later that afternoon after a few rays of sunshine had broken through -- she was gone!
I read that bumblebees sometimes forage into the night as well as during bad weather, their dense, hairy coats insulating them from the elements. However, sometimes they overdo it. If their body temperature drops much below 86°F (30°C) they can't stay airborne. Of course they can maintain that warm body temperature in colder air, but they must remain very active to do so. If a bee finds itself trapped away from its colony with night coming on or it turns cold fast, they may spend the night on a flower head, their metabolic rate much reduced, leaving only when it warms up the next day.
A BUMBLEBEE'S CORBICULA
Over 250 species of bumblebee are known so identifying them to species level can be a challenge. In fact, often other kinds of bees are confused with bumblebees, especially carpenter bees. In southern Mississippi I see many more carpenter bees than bumblebees. Carpenter bees generally have hairless, shiny abdomens (the big rear-end segments) while bumblebee abdomens are hairy. You can see that our marigold bumblebee is hairy.
Also, bumblebees are best distinguished from other kinds of large, fuzzy bees by the form of the female's hind leg, which is modified to form a corbicula. The corbicula, sometimes called the pollen basket, is a shiny, hairless, concave surface surrounded by a fringe of hairs. It's used to transport pollen. In similar bees the hind leg lacks the concavity and pollen grains are merely wedged into the hairs for transport.
Drastically enlarging and overexposing the photo of our bee's hind leg with PhotoShop, I got what's shown at http://www.backyardnature.net/n/09/091004bc.jpg.
Can you see the concave corbicula? It has water droplets inside its scoop part. Notice how longer hairs at the corbicula's base curve inward, sort of extending the scoop's sides so that the corbicula can hold more pollen.
A picture-key to some of North America's bumblebees is found at http://www.bumblebee.org/NorthAmerica.htm.
APHIDS ON THE CORN
A few of our garden corn plants are heavily infested with aphids. You can what that looks like at http://www.backyardnature.net/n/09/091004ao.jpg.
A view of the aphid world beneath a corn blade, showing aphids of all sizes, most unwinged but one with wings, some discarded exoskeletons, and a couple of large, round, brown ones can be seen at http://www.backyardnature.net/n/09/091004ap.jpg.
It looks like two species are shown there mingling. The most abundant one, with pear-shaped bodies, are probably Birdcherry Oat Aphids, RHOPALOSIPHUM PADI. A few, such as the larger one to the left of the winged one in the picture's center, display boxy thoraxes (the middle body segment) and look more like aptly named Corn Leaf Aphids, RHOPALOSIPHUM MAIDIS.
The Birdcherry Oat Aphid's common name reveals something about the species. Birdcherry is a kind of Eurasian cherry tree, so we learn that this aphid species is invasive in North America. The Oat in the name refers to the oat plant, and that points out that during the Birdcherry Oat Aphid's life cycle it alternately lives on two different plants -- winters on cherry trees and closely related species, and summers on oat plants and closely related grass species (such as our corn).
The Birdcherry Oat Aphid egg phase takes place on buds of cherry-related trees in the winter. When eggs hatch in the spring the larvae, normally all females, form colonies on the upper sides of leaves and in blossoms. Three to five generations occur there, the average female producing about 70 offspring. With warmer weather winged females are produced who migrate to a Grass-Family plant such as corn where they produce generation after generation of females. Toward the end of summer winged males begin to be born and these together with winged females migrate back to their cherry-related host trees where more males and females are produced. They sexually produce eggs that are laid in bud axils on young branches, and the life cycle starts over.
This alteration of host species, with the hosts being very different plants, and males and winged individuals being produced only when they're needed, is typical of other aphid species, though of course usually other species employ different hosts.
In the above picture of many aphids on the bottom of a corn blade, did you notice at the top, right the two large, tan-colored, spherical-bodied aphids? Those are dead aphids called "mummies."
Aphid mummies result when a female parasitic wasp inserts an egg into the aphid. When the egg hatches the larva feeds on the aphid's internal body parts, eventually killing and emptying the "skin" or exoskeleton. Often you can find aphid mummies with neat holes in their tops or sides, even with the holes' "lids" still attached to one side like the top of an open tin can. This is where the parasitic wasp that has developed inside the aphid has escaped.
Though I've seen aphid populations where nearly every mummy had such holes, with a handlens I checked dozens of such mummies on our corn plants but they all showed only dark spots on their interior side walls, which I'm guessing were the parasitic wasps' pupae from which later the adult wasps will emerge and cut their ways from the aphid's shell.
At http://www.backyardnature.net/n/09/091004gh.jpg you see something abundant nowadays, bound to land on your shirt or hair as you hike along trails through grassy areas. It's a grasshopper nymph.
Grasshoppers undergo simple metamorphosis, with immature grasshoppers looking more or less like adults, except that they're smaller and wingless or with reduced wings. Immature grasshoppers are known as nymphs. The one in the picture is clearly a nymph because its oval, finely pitted wings are only about a quarter of the grasshopper's length. On adult grasshoppers the wings project well beyond the abdomen's rear end.
As nymphs grow they molt several times, shedding their "skins," or exoskeletons. Each progressive stage of nymph development is referred to as an "instar", so we might speak of a 2nd instar grasshopper or a 4th instar one. The final molting results in a full-size adult with full-size wings. Though it varies with species, five or six instar stages usually take place. The time from egg to adult typically is 40 to 60 days. Probably that's a 5th instar nymph in the picture.
While hiking trails through grassy areas nymphs pop out of the grass like popcorn, thumping against your legs or landing wherever there's place for them. They jump a yard or more but only the adults fly, and those fly ten feet or so before fluttering to the ground. Some species make loud cracking sounds as they fly but the one in the picture is quiet. I can't figure out which species it is -- just too many of them.
A ROSE GALL WITH A STORY
Along the gravel road leading up from the valley some "wild rose" bushes have the growths on them shown at http://www.backyardnature.net/n/09/091004gl.jpg.
This is the road I jog each morning so I've been watching the growths form for months, slowly enlarging and passing through several color stages. The big one on the right is a little larger than a golf ball. The whitish mess at the left is what's left of last year's edition of the same thing. You've probably guessed that they're galls. As in the case with most but not all galls, female insects caused them when they inserted their eggs into the plant resulting in tumorous growth around the eggs, and eventually the gall. Larvae from the eggs will eat the gall's relatively soft tissue, then metamorphose.
Thousands of insect kinds form galls on thousands of kinds of plant, and typically each insect has a specific plant or kind of plant it bestows with its galls, and each insect/plant combination produces a characteristic gall. In the present case the host plant is the Sweetbrier Rose, and the 0.16-inch long (4 mm) insect causing the gall is a member of a group of tiny wasps called gall wasps. Sometimes the species is known as the Bedeguar Gall Wasp; it's DIPLOLEPIS ROSEA. You can see from the species name that it specializes in roses.
Someone in the UK has produced an excellent page with many pictures showing the Bedeguar Gall Wasp working on a rose, accompanied by detailed information, at http://hedgerowmobile.com/Diplolepisrosa.html.
The gall itself is eye-catching enough to have several names, including Mossy Rose Gall, Bedeguar Gall and Robins pincushion. The galls once were used medicinally against colic and as a diuretic.
THE SWEETBRIER ROSE
Jepson's Flora of California, the most useful flora for southern Oregon, lists eleven "wild rose" species. Of those eleven species, nine are native and two are invasive. It happens that the spines or prickles of the nine native species are slender and straight, with their bases not particularly enlarged. The two invasive species' spines, however, are curved backward and are very thick-based, or catclaw-like. You may have noticed that the spines on the Bedeguar Gall Wasp's rose bush were very thick-based and recurved, so it's a "weedy species." It's the Sweetbriar or Eglantine Rose, ROSA EGLANTERIA, native to Europe and western Asia. It's invasive all across the world, though, and coast-to-coast in North America.
During the summer ours produced fragrant, pink flowers but now it bears only the oblong, red hips shown at http://www.backyardnature.net/n/09/091004ra.jpg.
The second weedy, invasive rose species we have here, the Dog Rose, Rosa canina, is similar, but can be distinguished from the Sweetbriar Rose by a simple trick, or field mark, if you know it. That is, the leaves and sepals of the Sweetbrier Rose are "glandular" while on the Dog Rose they're "glandless." You can examine a leaflet underside of our plant at http://www.backyardnature.net/n/09/091004rb.jpg.
See those globular, transparent items, like dewdrops atop stubby little hairs? Those are stalked glands. The Sweetbrier Rose's sepals are similarly glandular. One supposes that the glands are sticky or contain chemicals making insects feel unwelcome there.
PACIFIC DOGWOODS FRUITING
Last spring we saw that the Pacific Dogwood's flower heads are similar to those of the Eastern Dogwood, except that they're larger and usually bear four white, petal-like bracts, not five. Our Pacific Dogwoods are fruiting now, and the fruits are a good bit different from the East's, as you can see at http://www.backyardnature.net/n/09/091004dw.jpg.
The Pacific species produces many more fruits per cluster than the Eastern, and the fruits are much more closely packed. They're not quite as shiny and red, either.
Dogwood fruits usually are regarded as drupes, a drupe being a fleshy fruit with one hard-shelled seed, with the fruit not splitting open when mature. Sometimes a fruit turns up holding two seeds, however, making the fruit a berry.
PINK HONEYSUCKLE FRUITING
Another fruiting plant catching anyone's eye these days with its glossy, succulent, red fruits is shown at http://www.backyardnature.net/n/09/091004hs.jpg.
Especially because of the way the fruiting heads emerge from the center of a roundish leaf, you may recognize this as a honeysuckle. It's the Pink Honeysuckle, LONICERA HISPIDULA var. VACILLANS, fairly commonly occurring here as a vine twining up shrubs along dry, sunny, weedy roadsides, at woods edges and in open woods. A few months ago the vines bore spikes of inch-long, paired, pinkish white, fragrant flowers. It's native from British Columbia along the Pacific to southern California and maybe into Mexico.
There's another closely related honeysuckle, Lonicera interrupta, with similar fruits but yellowish flowers over much of the same area where Pink Honeysuckles occur and at this time of year when flowers aren't available they could be hard to distinguish -- if you don't know a neat identification trick, or field mark. Pink Honeysuckle leaves bear very obvious stipules at the bases of their petioles, while the yellow-flowered species doesn't. The stipules are seen at http://www.backyardnature.net/n/09/091004ht.jpg.
In that picture the large white area at the left is the bottom of one of two leaves arising from a "node" on the stem (the leaves are "opposite"). At the leaf's base its short petiole curves upward to attach to the stem, and then the rounded, green, upward-flaring, ear-like thing is the stipule, with the other stipule arising opposite it.
A wide variety of birds eat the fruits.
Unfortunately the fungal pathogen causing sudden oak death, Phytophthora ramorum, inhabits Pink Honeysuckle's leaves. In some places in California and Oregon sudden oak death is killing nearly all the oaks and tanoaks, so any effort to control the disease must take into consideration the presence of this wonderful honeysuckle.
In this spring's May 3rd Newsletter I introduced the California-laurel, or Oregon-myrtle, UMBELLULARIA CALIFORNICA, whose shiny, evergreen leaves are powerfully fragrant with an odor something like sweet- spicy peppermint mingled with menthol. The leaves are often used in cooking. That Newsletter entry, with a nice picture of the tree's yellow flowers, is online at http://www.backyardnature.net/n/w/c-laurel.htm.
Now our California-Laurels are fruiting, as shown at http://www.backyardnature.net/n/09/091004um.jpg.
The inch-long fruit, which technically is a drupe, turns yellowish green to purple when mature. The one in the picture is almost mature. Note the fruit's "cupule" (the enlarged fruit-stem) from which it dangles. Such cupules are common in the California-Laurel's family, the Laurel Family. Sassafras belongs to this family and you may remember that Sassafras fruits arise from similarly enlarged cupules. In the picture you can also see several silvery flower buds, which will open next spring.
Mature California-Laurel fruits can be eaten raw. The seeds are a bit bitter but when roasted or parched they lose their bitterness and can be eaten whole or ground into a powder from which bread can be made. Besides seasoning stews with the baylike leaves, a tea can be made from them. I read that the tree's root bark can be used as a coffee substitute; I'm guessing that it must be roasted and ground first. You might guess that such an aromatic plant must have had many traditional medicinal uses, and that's right -- so many that no particular ones stand out.
A superb article on how to prepare food from California-Laurel's vegetative parts and fruits is at http://www.paleotechnics.com/Articles/Bayarticle.html.
NUTRIENT DEFICIENCIES IN CORN
At http://www.backyardnature.net/n/09/091004pk.jpg you see a corn leaf blade in the garden. It's easy to be wrong when diagnosing illnesses but I'm thinking that the leaf's problems are caused by deficiencies in both potassium and phosphorus. Here are the main corn-blade symptoms of deficiencies of the main nutrients:
NITROGEN: general yellowing of plant, especially toward tips of blades
PHOSPHORUS: purple coloration on blades
POTASSIUM: Yellow and brown coloration of blade margins
SULFUR: on younger blades, yellow striping running lengthwise between veins
ZINC: on upper blades, yellow striping starting at midrib in center of blade, then may progress outward
You can see examples of these symptoms at http://plantsci.sdstate.edu/woodardh/soilfert/Nutrient_Deficiency_Pages/CornD.html.
The blade in the picture displays the purple of phosphorus deficiency, plus its yellow and brown margins suggest potassium deficiency. Both of these deficiencies may result from our garden's heavy, clayey soil, and the corn having been planted when the ground was still cold this spring. Corn planted later when it was warmer now stands taller and shows fewer nutrient deficiency problems, and even has fewer aphids.
COLORS OF SIMPLICITY
The other day I passed by Anita's kitchen table as she was juicing grapes. On the table several pails of grapes surrounded a random collection of other fruits from backyard trees and vines, as shown at http://www.backyardnature.net/n/09/091004__.jpg.
It means a lot to me to coexist with such color and texture in my everyday life, to have the time to admire these things and take them into my own spirit. Such gorgeousness satisfies a great hunger in me.
In fact, it's interesting that some people considering my disinterest in material wealth seem to think that I live as I do because I strive to "be good" in an ethical sense. I like thinking of myself as living ethically, but I have to admit that mostly my lifestyle results from something else entirely.
Much of the reason I live as I do is because I am such a gluttonous, sensual fellow. Remember that when I left the farm in the 1960s I weighed 340 pounds. I am programmed for gluttony and I know all about it firsthand.
It's just that over the years my tastes for what I'm hungry for have changed. Somehow, one day I began hungering more for a healthy, good-looking body (and the women that such a body might catch) than I did the greasy hamburgers that earlier I'd craved. I developed an irresistible hankering for free time to do what I wanted, a desire much stronger than my wants for things that cost money. I found myself with an all- consuming lust for freedom, and that passion simply blew away all appetite I'd had until then for the comforts and securities that most people strive for.
Moreover, I became epicurean in my tastes. It wasn't enough, for instance, to eat healthily: I wanted to taste that healthy food with intensity. Experimenting in ways to satisfy that special hunger I blundered onto the discovery that food tastes best when it's eaten with great moderation. The same with women and good music -- all things complex and worthy enough to be interesting are best enjoyed when ravenous for them.
Commonness never is admired, but rarity is a quality of any treasure. Indulgence deadens our senses, but hunger imparts an edge to flavors no fancy chef can attain. A preoccupied mind overlooks much, but an unhurried mind at peace and emptied of distractions can dwell on any loveliness that happens along.
"I make myself rich by making my wants few," Thoreau said, having recognized the principle long before I.
The cold, rainy season has arrived in the Pacific Northwest. Therefore, despite my having enjoyed such a wonderful summer with my friends and having been treated so well in every respect, tomorrow, Monday, I'm boarding a Greyhound bus once again, heading to warmer climes. I doubt that this time next week I'll be in a shape to write coherently, so probably I'll skip next week's Newsletter.
See you down the road in a couple of weeks.
Best wishes to all Newsletter readers,
All previous Newsletters are archived at www.backyardnature.net/n/.
Visit Jim's backyard nature site at www.backyardnature.net