Tuesday, October 1, 2013
Our friends who follow this blog know that I started it to feature nature at Creasey Mahan Nature Preserve where I volunteer.
Our website at Creasey has been redesigned and really looks wonderful. Part of the design was to incorporate KY Natural Inquirer into the website itself. The blog still exists, but you will need to look for it at http://www.creaseymahannaturepreserve.org/blog/. Let us know how you like the new look!
Tuesday, September 17, 2013
When you take a walk during this time of year, whether at the Nature Preserve, or just around the block near your home, your ears may be overwhelmed with the buzzing song of insects. Insects are usually unnoticed by most people, except for a passing comment perhaps. "Boy, those bugs sure are loud today! I wonder what's making all that noise." Because they are cold blooded, insects need hot days to warm up their instruments. You won't hear them on a cool morning. But if you listen, you will notice them around midday. By late afternoon or early evening, more insects will have joined the chorus. They are singing love songs, and looking for a mate!
These sounds are made by different insects, depending on the time of day you hear the singing. During the day, the loud buzzing is usually made by a cicada. There are several species, including an annual cicada and the dreaded 17-year species. A cicada is 1 to 2 inches long, with a blunt head and clear wings. Similar to true bugs, it has a mouth part for sucking. Like a drinking straw with a sharp end, the cicada's mouth part can pierce a woody plant and suck up sap. The female cicada has an ovipositor folded under her abdomen. She uses it to slice into the tip of a branch and deposit eggs inside. After the eggs hatch, the young cicadas (called nymphs) drop to the ground and use special front legs to tunnel into the soil. Underground, they feed on root sap and grow in dark burrows for many years.
Each cicada crawls out of the ground and up onto a tree or other woody plant. Then the cicada nymph inflates itself with air, moisture, and blood, splitting open its exoskeleton. Eventually, the grown-up cicada emerges and leaves its exoskeleton on the bark. Males begin to call for a mate, during the day, and females listen for their courting call. After mating and laying eggs, the adults die. Some people call cicadas locusts, but they are not. The confusion happens because locusts, which are a kind of large grasshopper, sometimes show up in tremendous swarms. However, locust swarms are very destructive. They devour entire crops, while cicadas feed only on plant juices and do minor damage to trees.
In the evening, other insects sing the buggy serenade. Katydids are some of my favorites, as they argue, "Katy did!" and "Katy didn't!" As a child I always wondered what Katy was supposed to have done! Katydids look like large green grasshoppers with super-long antennae. Indeed, another name for these insects is long-horned grasshoppers.
Like Katydids, crickets rub a sharp ridge on one wing against a rough part of the other. As it rubs, its wings vibrate. The vibration amplifies the sound. This singing style, known as stridulation, sounds like buzzes, chips, chirps, or clicks. Crickets. Crickets hold their wings flat on the back. Their long, slender antennae extend beyond the body. The female has a single long tube, called an ovipositor, for laying her eggs in soil or plants.
This is the time of year to enjoy the natural sounds of nature. Turn off you iPod and turn on your ears!
Wednesday, August 21, 2013
Luna moths can be found in deciduous hardwood forests, where a variety of trees including white birch, persimmon, sweet gum, hickories, walnuts, and sumacs serve as host plants for the young caterpillars. The adults are very strong fliers and are attracted to lights. Adult Luna Moths don't eat; in fact, they don't even have a mouth. They only live for about a week, and their only purpose is to mate.
|Luna Moth Female|
Luna Moth Male
Female Luna Moths release a chemical at night which attracts males. Notice that the antennae of the male are large and feathery, all the better to detect and locate the female by her pheromones. Adults die shortly after mating or laying eggs. Usually, two generations are born each year (that means that moths that spent the winter in a cocoon will hatch, mate, and lay eggs; then their children will hatch, mate, and lay eggs which will hatch and make cocoons for the Winter). Luna Moths were once very common, but are now considered an endangered species in some areas.
The eggs hatch in about one week and the caterpillars are sedentary and solitary feeders. They click their mandibles when threatened and can vomit fluids to deter predators. Leaves and silk are used to spin papery brown cocoons in litter under the host plant. Adults will have one brood from May-July in the north, two to three broods from March-September in the south. The caterpillars have 5 "instars", in which they shed their skin to allow growth into a bigger size.
Predators of Luna moths include bats, owls and some hornets. Do you think the large "eyes" on their wings would discourage a predator? For a terrific video showing an adult emerging from the cocoon, go to http://youtu.be/atOSro3_W7c.
Thursday, August 1, 2013
When is an acorn not an acorn? Sometimes you look up into the branches of an oak tree and see some peculiar looking acorns. They seem to encircle a twig, and are very deformed looking. Well, they aren't acorns at all, but some variety of oak gall.
Gouty and horned galls are abnormal growths or swellings comprised of plant tissue found on leaves, twigs, or branches. These deformities are caused by a tiny, non-stinging, wasp which produces a chemical or stimuli inducing the plant to produce large, woody twig galls. Most galls are aesthetically not pretty, but normally cause little damage to tree. However, severe infections may bring about the decline of the tree. Chemical control is seldom suggested for management. The horned oak gall has small horns that protrude from around the circumference of the gall. It can be found on pin, scrub, blackjack, and water oaks. The gouty oak twig gall is smooth and can be found on pin, scarlet, red and black oaks.
In early spring a tiny wasp of the cynipidae family emerge from woody stem galls. The females lay eggs on the veins of the oak leaf buds. Male and female wasps emerge from these tiny, blister type galls on the leaf vein about mid summer. Mated females deposit eggs in young oak twigs. The next spring small swellings develop on the twigs and enlarge over the next two or three years. The galls provide protection, food, and shelter for the developing larvae. When the larvae reach maturity, the horned galls developed small spines or horns. An adult wasp emerges from each horn and another life cycle of wasps begins.
If you look carefully at other plants, you may find other galls as well, in golden rod for example. Just keep a sharp eye out for them!
Tuesday, July 16, 2013
The older I get, the more confused about similar things sometimes. On the other hand, there are many similar things in nature that I have always had trouble distinguishing. On a recent walk around the grounds of the Nature Preserve, I found two of those similar things growing right next to each other. Blackberry and black raspberry are two different fruits. A person who is not that exposed to berries will surely have a hard time distinguishing one from the other; but you can never blame them because it is really hard to tell which is which by simply looking at the fruit itself. Bramble fruits are characterized by the clustering of smaller fruits (druplets) to become one bigger clump of fruit.
Blackberries are perennial plants which typically bear biennial stems ("canes") from the perennial root system. In its first year, a new stem, the primocane, grows vigorously arching or trailing along the ground and bearing large palmately compound leaves with five or seven leaflets; it does not produce any flowers. In its second year, the cane becomes a floricane and the stem does not grow longer, but the lateral buds break to produce flowering laterals (which have smaller leaves with three or five leaflets). First- and second-year shoots usually have numerous short-curved, very sharp prickles that are often erroneously called thorns. These prickles can tear through denim with ease and make the plant very difficult to navigate around. Unmanaged mature plants form a tangle of dense arching stems, the branches rooting from the node tip on many species when they reach the ground. Vigorous and growing rapidly in woods, scrub, hillsides, and hedgerows, blackberry shrubs tolerate poor soils, readily colonizing wasteland, ditches, and vacant lots. Blackberry leaves are food for certain caterpillars; some grazing mammals, especially deer, are also very fond of the leaves.
The flowers are produced in late spring and early summer on short racemes on the tips of the flowering laterals. Each flower is about 2–3 cm in diameter with five white or pale pink petals.
The drupelets only develop around ovules that are fertilized by the male gamete from a pollen grain. The most likely cause of undeveloped ovules is inadequate pollinator visits. Even a small change in conditions, such as a rainy day or a day too hot for bees to work after early morning, can reduce the number of bee visits to the flower, thus reducing the quality of the fruit. Incomplete drupelet development can also be a symptom of exhausted reserves in the plant's roots or infection with a virus such as Raspberry bushy dwarf virus.
The black raspberry has lots of tiny prickles on the stems, and larger leaves. When you pick up the black raspberry from the plant, you will notice that it has become hollow. In other words, its stem (more appropriately termed as receptacle) was pulled out from the fruit and remained with the plant. This is not the case with blackberries because when you harvest them, you will almost always retain its stem.
Black raspberries become hollow in the middle when picked from the main plant whereas the blackberries retain its stem. Black raspberries are harvested at an earlier time while blackberries are more sensitive to cold temperatures. In terms of looks, blackberries are said to be smoother and shinier than black raspberries. Blackberries are native fruits in North and South America, as well as, in some parts of Asia and Europe whereas black raspberries are only indigenous in North America.
Black raspberries have less commercial value than blackberries.
Wild berries are tasty, but you will get scratched up - just count on it. And you are likely to get bit by chiggers and other bugs.
Thursday, June 20, 2013
A great crowd of frog enthusiasts joined Bill Dean, aka Dr. Frog, at the frog pond last week, and not one person said "EWW!" as he netted up frogs, tadpoles and eggs from the bottom of the pond. I was proud of everyone! The pond is home to green frogs and bullfrogs at this time of year, although other species can be found earlier in the spring. Green frogs live wherever shallow freshwater ponds, road-side ditches, lakes, swamps, streams, and brooks are found. Most often seen resting along the shore, they leap into the water with a loud "eek" when approached. Inhabiting the terrestrial and aquatic habitat boundary, green frogs employ a simple leap to leave behind their many and faster terrestrial enemies that cannot cross that boundary.
Dr. Frog noted that female green frogs have a white throat, while the males have yellow throats. Actually, they don't have much green color at all. Green frogs breed in semi-permanent or permanent fresh water.
Males call from and defend their territories. The distinctive call sounds like a plucked banjo string, usually given as a single note, but sometimes repeated, during the breeding season from April to August. They were quiet while we were all there, but by Wednesday afternoon, the chorus was in full voice, much to my surprise. Their territories can't be too big, given the number of frogs in close proximity. See how many you can count in this short video.
Another way to tell the males from females is to look at the tympanum, or ear, next to their eyes. Mature females are typically larger than males, but the male tympanum is twice the diameter of the eye, whereas in females, the tympanum diameter is about the same as that of the eye. The dorsolateral ridges, prominent, seam-like skin folds that run down the sides of the back, distinguish the green frog from the bullfrog, which lacks them entirely.
Actual mating involves amplexus, whereby the male grasps the female with his forelimbs posterior to her forelimbs. The female releases her eggs and the male simultaneously releases sperm which swim to the egg mass. Fertilization takes place in the water. A single egg clutch may consist of 1000 to 7000 eggs, which may be attached to submerged vegetation. Yet few of the tadpoles reach maturity, since they are the favorite food of just about every other animal living in the pond.
Green frog tadpoles are olive green and iridescent creamy-white below, and eat mainly diatoms and algae. Adults eat insects, worms, and occasionally other small frogs and fish. Rather than chase their prey, they sit and eat whatever comes by. Metamorphosis (changing from the fully aquatic tadpole, to an air breather with legs) can occur within the same breeding season or tadpoles may overwinter to metamorphose the next summer. Males become sexually mature at one year, females may mature in either two or three years. Following metamorphosis, juvenile green frogs often travel from their natal ponds to neighboring ponds. Movements of up to three miles have been documented.
Like other frogs, green frogs have well developed senses. Their bulging eyes allow them to see in many directions. The round spot behind the eye, called the tympanum, or eardrum, is used for hearing. This specialized patch of tissue vibrates when sound waves hit it. The vibrations are then interpreted as sound by the frog's brain.
Yeah, no doubt about it. Frogs are cool!
Friday, June 14, 2013
You never know the questions that may arise from a simple walk in the woods. Last week, I visited the Morgan Conservation Park in Oldham County for the first time. Our target was the nightjars known to live there. Nightjars? The family to which Whip-Poor-Wills and Chuck-Wills-Widow belong - in other words, birds that sing at night. We found a redbud tree with the oddest thing - it looked like some bug with a hole puncher had taken bites out of the leaves. I've never seen this before, and sent it around to other nature friends.
Turns out that these holes were chewed by a leaf-cutter bee. What? Yes, a native bee species. It's time to investigate bees a little more. I knew that sometimes it's hard to tell bees and flies and wasps apart, but I was astonished to learn about native bees! Some bees are "solitary," not living in hives with a queen like the honey bees do. Both males and females work for a living. This leafcutter digs a burrow in the ground, and uses the leaf pieces to separate each egg chamber from the next.
We are familiar with honey bees, and the problems they are having these days. But did you know they are not native to the New World? Honey bees arrived with European settlers about 400 years ago. Read this terrific brochure from the USDA about native bees. For example, there are over 4,000 different species of native bees in the United States! Many of our native bees are quite specialized, such as the blueberry bee or the squash bee.
|Bees or Wasps?|
Upper left: An eastern yellow jacket wasp
Lower left: The familiar black and yellow mud dauber wasp
Upper right: A digger bee,
Lower right: The nomad bee
Bees are descended from wasps. Most wasps are carnivores; they either prey upon or parasitize other insects or spiders, and use this rich protein source to feed their young. About 125 million years ago, when the first flowering plants evolved, some wasps made a switch from hunting prey to gathering pollen for their brood. Perhaps they were hunting for insects that visited flowers and ate some of the pollen or drank the nectar along with their prey. It didn’t take much to find the advantages of consuming pollen over hunting. Pollen is rich in proteins and doesn’t fight back, so it is easy to imagine why the bees became vegetarians. Gathering pollen and nectar requires certain adaptations different from those of hunters, so they started to change, to evolve to meet these requirements and consequently became bees.
How to tell the difference between honey bees and bumble bees, the two most familiar bees?
Carpenter bees are a native species with a bad reputation. They have powerful jaws called mandibles with which they can excavate tunnels in wood. Fortunately they prefer soft wood and dislike paint or other finishing materials. It is possible to prevent them from doing serious damage to wood structures by taking simple precautions, such as painting or staining the wood. These gentle giants are called carpenter bees, and very likely you have seen some of them and their handiwork. There is usually a pile of sawdust below the opening of the hole during the early nesting and burrow excavation season. These bees create “particle board” spiral partitions between adjacent cells. Most bees construct spiral partition cell closures, a trademark of bees rather than wasps.
|Green Metallic Bee - Agapostemon splendens|
|Robber Fly with Bee Prey|
Further research found that this was in fact a robber fly. And you thought flies were only interested in garbage and manure! There are two simple ways to tell a fly mimic from a bee. First, look at the wings: bees have four wings, but flies have two wings. Second, look at the antennae: bees have elbowed antennae, while many flies have short, stubby, or hair-thin antennae. If you can't see the antennae, you're probably looking at a fly. A site called Beespotter has lots of great info on bees and bee look-alikes.