Of all the insects I’ve found in milkweed patches over the years, the Hummingbird Clearwing is one of my favorites. It is a species of sphinx moth, named for its habit of hovering at flowers while it gathers nectar with its proboscis in a manner similar to that of hummingbirds. In fact, they are often mistaken for hummingbirds. The transparent wings, light brown thorax and dark chestnut abdomen are the field marks to look for. A diurnal moth, the Hummingbird Clearwing can often be found during the day in milkweed patches.
Milkweed is in full bloom right now, presenting the perfect opportunity for young and old alike to discover the multitude of butterflies, beetles, bees and other insects that are attracted to these magnificent flowers. If you visit a milkweed patch, don’t leave before getting a good whiff of the flowers’ scent – one of the sweetest on earth. How many of the insects you find are carrying milkweed’s yellow pollen “saddlebags” on their feet? You might want to check out my children’s book, MILKWEED VISITORS, which I wrote after spending the better part of one summer photographing the various insects I found visiting a milkweed patch. ( http://basrelief.org/Pages/MV.html )
Liverworts, along with mosses and hornworts, are classified by botanists as bryophytes – non-flowering plants that lack vascular (conductive) tissue. It is possible, even likely, that liverworts were among the first plants to make the transition to life on land. Their appearance varies according to the stage in which you see them, but the plants we think of when we think of liverworts are very small (less than an inch in diameter and about 4 inches in length) and can be relatively flat, growing very close to the ground. Liverworts have two basic stages, the dominant one being the flattish, leaf-like gametophyte. It produces male sex organs (antheridia) which produce sperm and female organs (archegonia) which produce eggs. The stalked, fringed, palm tree-like structures in the photograph are egg-producing archegonia, and the stalked, lobed structures are antheridia. Both are less than an inch tall and are produced on the same plant (unlike 80% of liverwort species that produce their sex organs on separate plants). The sperm must reach an egg in order for fertilization to take place, and it usually does this by swimming through rain water or dew. Once fertilization occurs, the second stage of the plant, or sporophyte, develops. The sporophyte produces spores, some of which will grow into gametophytes and the cycle (called alternation of generations) will repeat itself.
Yesterday’s post was, as you quickly guessed, an eyespot from the forewing of a Luna Moth, Actias luna, one of North America’s giant silkworm moths. With a wingspan up to 4 ½,” it is one of our largest moths. Markings that resemble eyes are found not only on moths, but also on butterflies, birds, fish and reptiles. When they occur on butterflies and moths, eyespots are usually on the wings and are thought to scare off potential predators as well as to direct attacks away from vital body parts. After emerging from their cocoons, Luna Moths live for only about a week, during which time their sole mission is to mate. Like many other ephemeral insects, Luna Moths have no mouthparts and thus, do not eat as adults. (The phenomenal number of Luna Moths this summer may, in part, be due to the mild winter we had, which allowed more pupae to survive.)
The next time you’re in a field, stop and take a close look at a few of the grasshoppers you find there. Chances are great that you will see tiny, red mites on some of them. These Red Grasshopper Mites, close relatives of ticks and spiders, go through three stages: larva, nymph and adult. The larvae (6-legged) attach to the base of a grasshopper’s wings, where they suck the grasshopper’s blood. The nymphs and adults (both 8-legged) are free-living and feed on grasshopper eggs. Each Red Grasshopper Mite nymph requires more than two grasshopper eggs to become an adult. An adult male Red Grasshopper Mite requires three grasshopper eggs for reproducing, and each female, seven to eight eggs. After breeding, a female mite deposits up to 4,000 eggs. Entomologists believe that mites reduce grasshopper survival and reproduction dramatically.
It’s easy to miss Blue-eyed Grass (Sisyrinchium angustifolium), as its flower is only about ½” in diameter and the plant only reaches a height of six to twelve inches. Blue-eyed Grass is a member of the Iris family, not, as its name implies, a member of the Grass family, although it does have stiff, grass-like leaves. Dark lines on its petals and sepals may well serve as nectar guides, leading pollinators to the yellow center. Each blossom is open for only a day at most. Typically you find Blue-eyed grass growing in sunny, wet fields, often on elevated soil — Thoreau noted that if you followed Blue-eyed Grass through a wet meadow,
you could keep your feet dry.
Two common spiders that we often see carrying their egg sacs are the wolf spider and the nursery web spider. Wolf spiders attach their egg sacs to their spinnerets, whereas nursery web spiders carry them with their mouthparts. When nursery web spiders are about to hatch, the mother puts her egg sac into a silk tent she has spun, and they live there for a week or so. When a wolf spider’s spiderlings emerge from their egg sac, they climb up onto their mother’s abdomen and cling to it while their mother continues to hunt for food. After about a week, when partially grown, the spiderlings disperse, either by ballooning through the air on silk strands or simply by scurrying off along the ground.
If you’ve been traveling on sunny dirt roads lately, chances are that you have seen White Admiral butterflies all over them. They are in the road to obtain salts and minerals that have leached from the soil into standing puddles and moist dirt. Because butterflies do not have chewing mouthparts as adults, they must drink their meals. While nectar is their main source of nutrition, males often supplement their diet with these minerals. The act of acquiring nutrients in this manner is referred to as “puddling.” If there’s no water around, a butterfly may regurgitate into the soil and then drink in the hope of retrieving minerals. In addition to finding butterflies on dirt roads, look for them puddling on animal scat.
Like many flowering plants that blossomed two or three weeks early this year, Great Northern Loons (previously called Common Loons) got an early start to their nesting season. While some adults are still sitting on eggs, some chicks can be seen hitching a ride with their parents. Even though chicks can swim as soon as their down dries, their inability to regulate their body temperature for the first two weeks and their need for protection from predators at this vulnerable time, they are brooded on the backs and under the wings of their parents. After a couple of weeks, however, the chicks are under their own steam and can be seen bobbing in the water near their parents. (Kayakers and photographers — extreme caution should be taken to avoid approaching loon nesting areas too close at this time of year.)
Great Blue Heron chicks are getting big enough so that you can easily observe them (can you find all four?). Occasionally you can even detect flies and other insects buzzing about them, which, given the fact that nest sanitation is not a priority for herons, is not surprising. While the parents do toss the eggshells out of the nest, feces, partly eaten prey and even dead chicks often remain in the nest. Also, parents feed their young by regurgitating into the nest and the chicks will regurgitate when disturbed. Unlike most song birds, Great Blue Herons re-use their nest year after year. It is quickly apparent why they add more sticks and boughs to their nest every breeding season – were that housekeeping for humans was that simple!
Baby birds like this robin are starting to fledge, and it’s the time of year when we see them on the ground, looking very vulnerable. Often we assume that such a bird has been abandoned, and with all good intentions attempt to “rescue” it and finish raising it ourselves. Young birds recently out of the nest are still cared for by their parents for several days, but the parents aren’t always in sight. Usually one parent is nearby, keeping an eye on its fledglings, feeding them and teaching them survival techniques such as where to find food and water and how to avoid predators – skills humans can’t provide. If a bird has feathers, is hopping around, and has a tail an inch or so long, it has probably fledged and not fallen from its nest accidentally. A good rule of thumb is to watch the bird for at least two hours to see if a parent comes to it before taking it to the nearest bird rehabilitator.