Sunday, October 3, 2010

Wild and Wooly

I am constantly amazed as I continue to make discoveries in the insect world.  I've named this blog "Wild and Wooly" to simply show a few interesting members of the insect community that have beautiful furry textures and also offer a few interesting facts about them.

Virginian Tiger Moth

 Moths and butterflies share the insect order, Lepidoptera, which is Greek for "scale wing".  They also share a few similar characteristics, but they are classified under different sub-orders and have several morphological differences...way too complex to go into here, so I will just stick with easy, interesting information and observations.

I think the furry appearance of butterflies and moths really add to their appeal, although this feature is sometimes not noticeable at first glance.  This very pretty Virginian Tiger Moth appears to have a beautiful white fur coat wrapped around his body. (I think he looks like a mighty snow king that reigns over a tiny winter fantasyland! OK, enough of my child-like imagination.) The "fur" on moths and butterflies isn't actually fur, but "hair-like" scales that serve several purposes. Since butterflies and moths are ectothermic (meaning they are unable to maintain a constant body temperature without an outside source, such as the sun), the hair on their bodies serve as an insulator to help keep their core temperatures at a functioning level once the air begins to get cooler. They must have a certain body temperature to be able to fly. This is especially important for moths, since they are mostly active at night and cannot rely on basking in the sun as butterflies do.

Since most moths are nocturnal by nature, the hair also serves as protection from bat predators by  absorbing the echolocation calls that bats emit. The fur can absorb so much of the echolocation signals that a bat may not even realize the moth is there. Speaking of bats...Another extremely interesting note regarding defensive mechanisms for moths: Tiger moths can emit ultrasonic "clicks" at a much faster succession than the echolocation clicks of bats, thereby "jamming" the calls of the bat pursuers. This results in the inability of the bat to accurately locate the exact position of the moth. This has actually been proven in scientific studies. It is unbelievable how these tiny, fragile insects have such powerful defensive tactics that go completely unnoticed by the human species!

Since I actually disturbed this Virginian Tiger Moth from his daytime resting period (he had been hiding under some brush that I had cut the previous day and flew out when I cleaned it up), he maintained a stiff posture while I was trying to photograph him. I don't know if he was playing dead or if he was actually in a state of "sleep" because he is not normally active in the day, but he would not move at all. I wanted to get a better picture of his face and eyes, but he kept the eyes obscured with his "labial palps", as you can see in the pictures. These are not legs, but actually mouthparts that are covered with tiny sensory hairs and scales. The moth uses these labial palps to keep the proboscis and eyes clean, and also uses them to assist in determining if something is a viable food source. 

I plucked the blade of grass the moth was holding onto and placed it on a flower, but he still would not move. I took one more picture of this beauty and then left him alone. I don't ever want to cause stress or harm to the creatures I'm photographing. When I returned a few minutes later he had flown off to a private, darker area no doubt to continue resting until his normal activity time, which would begin sometime soon after nightfall.

Miscellaneous butterflies
As a rule, moths are normally more plump and hairy than butterflies. In most cases, that is true, but I've included a few butterflies that I've encountered that do have lots of soft hair on their bodies. You may not notice this kind of detail because of their constant fluttering and busy activity, but as I've noticed with all insects, once you get a close look you notice all kinds of remarkable characteristics. Butterflies definitely adorn our world with beauty and grace, but just what is the purpose of the gorgeous fur on their bodies?

Butterflies warm their bodies by the sun, but like moths, they cannot maintain that body temperature when the fahrenheit dips down. This covering of hair (not really hair, but long hair-like scales) serves as thermal insulation as it does in moths. It also aids in protecting their soft bodies and adds water resistance, but there are also other specialized hairs and scales covering the entire bodies of butterflies (and moths) called "tactile setae" that serve a further purpose. Depending on the species, these tiny hairs may be on the eyes, antennas, body, wings, and legs and each are attached to special nerve cells, which relay information about the hair movement to the butterfly-this is very important for survival. The sensations the butterfly feels provides important feedback as to what is happening to him or to his immediate environment. You can see the many fine hairs and "fur" on this Least Skipper. It even appears that he has long eyelashes! These hairs serve a much higher purpose than just making him look adorable!
The tactile setae also serve a vital purpose for flight on butterflies and moths. The extremely specialized communication between setae and sensory nerves help the adult to sense wind, gravity, and the position of the head, body, wings, legs, antennae and other body parts. The fine hairs on the antennae sense both touch and smell. Butterflies' wings are covered by thousands of overlapping scales, which further strengthen, protect and insulate. They also aid in the flow of air along their wings as they fly. Delicate hairs that form fringed margins along the wings, as pictured below on this Pearl Crescent Butterfly, also provide important aerodynamic functions. 


Here is dorsal view of another tiny, Pearl Crescent Butterfly, showing lots of fine soft hairs. Another purpose for body hair is that of involuntary pollen transfer. As butterflies light from flower to flower inserting their proboscis into flowers, pollen will stick to the hairs on the legs, underside of the body, and even to the proboscis, and they will carry that pollen on to the next flower. Bees are true pollinators, but the butterflies do a fairly good job unintentionally!



Below is a picture of the beautiful Orange Sulphur Butterfly. As you can see, the sulphurs are also very hairy! These butterflies are relatively small, and while in flight their beauty cannot be truly appreciated! Patience and a macro lens help to capture the real beauty and innocence of nature that unfortunately often goes unnoticed!


The picture below is of a Common Wood Nymph. This beautiful brown butterfly has distinctive eye spots on their wings, which function as a special form of defense. If threatened, the wood nymph spreads its wings, displaying the eyespots, which often will distract a predator or possibly even scare it off! The occurrence of patterns and colorations are important survival strategies, (for example, mimicry and camouflage), and also necessary to attract potential mates.  The variation of the pigmentation of scales and how they are positioned and shaped can create beautiful illusions of iridescence and make the butterfly appear to have many more colors than they actually do. Beautifully colored scales also serve to attract a potential mate.

Actually, the properties of the scales on the wings and how they function is very highly complex. Scientists have even taken inspiration from the tiny crevices of butterfly wings to create a nanosensor technology that could detect weapons and explosives, due to the fact that their wings have acute chemical-recognition abilities. It is utterly amazing that such seemingly simple creatures of nature that we take for granted could have such an influence on modern technology!

This wood nymph is found in grassy areas, mostly in fields, open meadows and marshlands. I found a bunch of these in a beautiful open meadow while camping in West Virginia. Every morning they were in the same place under an old apple tree along the corner of an old wooden fence. I felt like they were much more tolerant of my presence than some of the other butterflies, and I truly enjoyed standing still and having them flutter and land all around me!


The Wooly Alder Aphid 
While walking along the shallow end of Lake Logan the other day, something caught my eye. At first glance it appeared that that there was a white fungus growing on a speckled alder sapling along the lake's edge. A closer inspection revealed an amazingly organized colony of hundreds of aphids with white fuzzy bodies packed shoulder to shoulder on a section of the alder.  (By the way, aphids are soft-bodied, tiny insects that suck the sap out of small tree branches, vines, flowers and plants of all kinds.) There are hundreds of different species, but I'll concentrate on the wooly alder aphid. Get ready for an interesting story!

The name, wooly alder aphid, is due to the aphid's ability to secrete a white, waxy filament from their abdomens that resembles white wool. Their bodies become completely covered with these entangled filaments, which serves as a protective defense from predators. Should a predator attempt to eat one of these plump juicy insects, they may just get a mouthful of waxy, wooly fuzz instead of a juicy meal, thus discouraging the attack!



Lets take this wild story from the beginning...The life cycle of this interesting aphid actually starts from the single egg that each female will lay in the bark of a silver maple tree. Once the eggs hatch in the spring the nymphs begin feeding on the mid-vein of new leaves of the maple. Amazingly, ALL young aphids nymphs are wingless FEMALES and they mature quickly and continually give live birth to MORE FEMALE aphids. The act of reproducing young that requires NO MALE INTERVENTION is called parthenogenetic reproduction. This FEMALE-ONLY colony builds very quickly and all remain relatively hidden underneath their own waxy strands.

In late June, they become winged and begin to fly to alder trees to carry on their life cycle on this second host. They resemble little tufts of cotton flying through the air. They continue to reproduce MORE FEMALES and produce more waxy filaments until the occupied areas of the alder begin to look cotton-covered. The population grows rapidly. All summer long they feed on sap and produce female clones.

When fall approaches. something incredible happens...hormones in their bodies change in response to temperature, day length, overcrowding, and quality of food, which suddenly causes WINGED MALES to be produced! The winged males and winged females then fly back to the silver maple trees where they  mate sexually this time and lay eggs, which will overwinter within the cracks and crevices of the bark. New generations will begin in the spring with the hatching of once again ALL-FEMALE wingless aphids (who will quickly become cotton-covered) and new large colonies will accumulate in the maples and then move on to the alders by June's end. (No real harm is caused to either the alder trees or the silver maple trees during the life cycle of this aphid.)

Interestingly, since the parthenogenetic nymphs are actually perfect clones of their parents, they are perfectly adapted to their environment from birth. The occasional mating ensures genetic diversity, which simply means chances for future survival of the species is increased because it allows the species to adapt to a new environment, should there be a change in their current situation.

The picture below shows a couple of ants crawling among the aphids. (There were many ants present, just not pictured). These ants actually protect and "farm" the aphids. They stroke the aphids with their antennas, which causes the aphid to release a drop of a substance rich in sugar that is produced from the sap they suck out of the tree. The ants highly desire this excrement, which is called "honeydew". They will fiercely protect the aphids in return for this honeydew-an example of one of the many mutualistic symbiotic relationships that occur in nature!


Another twist to the amazing life of the wooly aphid is that some insect predators will actually pull some of the wool off of the aphids and attach it to their own bodies to "fool" the ants so they can feed on the aphids without the awareness of the protector ants!!





Flower Scarab Beetle (euphoria sepulcralis)


Scarab beetles are very interesting creatures, with about 30,000 species worldwide. This particular one is a flower-loving scarab commonly named, the "Flower Scarab Beetle." This species is dark brown to black with metallic bronze and green reflections. (The iridescence of this one  actually caught my attention). Although some scarab beetles eat animal dung, the diet of the flower scarab consists of flower pollen, flower nectars and liquids from decaying fruits.  As you can see, this species is somewhat furry, giving them a "teddy bear" appearance!  This is the first time I've ever seen one and I was impressed at how darn cute it was! This one stood on the edge of a Queen Anne's Lace bloom and seemed to lean forward and look right at me! I think he sort of looks like a miniature moose! This is one of the more interesting insects I've had the opportunity to observe.

The ends of a scarab's antennas are made from 3 flattened plates called lamellae that can be compressed into a ball or fan out (as pictured above). When fanned out, this flower scarab is "smelling" the air. Antennas of insects are the primary olfactory sensors. They contain super-sensitive receptors that can also sense vibrations, assess temperature and humidity, and assist in locating food and mates. The scarab will flatten the lamellae when they're not needing to assess their environment (as pictured in the photo below).

Although very sluggish, the beetle still seemed to be quite coordinated as it slowly crawled along the delicate bloom, sometimes hanging upside-down by a leg or two. (Their strong legs are more adapted for digging than for precision climbing). I was careful not to intrude too closely, for if they feel threatened they will feign death and drop off the flower. He didn't seem to mind my curiousness though. I eventually saw a beautiful assassin bug nymph (that I will post in a future blog) that caught my attention and when I looked back, the scarab beetle had flown away to another bloom and I couldn't find him again.


This is not the best angle, but I read that while the scarab's head is buried into a flower, the rear, exposed part resembles a bee due to the coloration and markings, which could serve as a deterrent for a predator.

An interesting note...Scarabs (some extremely beautiful, shiny and colorful) have existed for millions of years, and the Egyptians regarded them as sacred. They were a symbol of resurrection and new life, and they used them for jewelry, amulets and seals for both the living and the dead.

Saturday, September 4, 2010

Color Me Beautiful





The brilliance of this Dogbane Leaf Beetle is certainly eye-catching and he is truly a creature of beauty. As he moves about, it appears he constantly changes color from every hue of red, gold, blue and green. The surface of this beetle's body is covered with tiny, slanting plates that overlap a special pigment. Some light rays reflect from the plates, while others reflect from the pigment. These different reflections cause interference that result in a psychedelic changing-of-colors. This prismatic phenomenon helps protect the insect by communicating to possible predators that he may be poisonous so chances will be less likely that he will be eaten or harmed. He will emit a foul smelling enzyme if disturbed. This gorgeous insect is very fun to watch! The beetles feed mainly on dogbane and milkweed and they pose no harm to humans or important vegetation.
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The metallic "armour" covers every bit of his body from his head down to his toes! Brilliance in motion!

What is this strange creature? It is actually the tail-end of a Gray Hairstreak Butterfly! At rest, this little beauty uses a technique of constantly rubbing his hind wings together, which makes the tail projections move about like antennas, while the coloration at the tips of the wings resemble eyes-an attempt to fool predators. As he collects nectar from various little flowers, tail-end in the air, he may only get a nip off his wings and still be able to escape unharmed. I was amazed at his coordination...diligently working on a flower with his nose down, yet keeping up the act on the other end, somewhat like a puppet.  It was very convincing-I really had to look closely when I first saw him in this position because I wasn't sure what it was at first!
Here is the full view of the Gray Hairstreak. He is actually very tiny and flies about eratically-you may not even notice him, but in good lighting he is very vivid. I love the tiny little stripes on his antennas and legs.


I was lucky to have noticed a slight movement in the leaves that revealed this juvenile Angle-Wing Katydid. This one has not yet reached maturity, but he was still quite large. Perfectly camouflaged, he blends in with the green foliage and is often more easily heard than seen. As you can see, the intricate patterns are quite beautiful as if painted on by a skilled artisan. The katydids are closely related to crickets, and they contribute to the wonderful insect "chorus" that can be heard in late summer and fall evenings with their chirps, buzzing and ticking. They create the sounds by rubbing a file on one broadened wing against a scraper of the other wing much like someone playing a fiddle.
Here is a different angle of the katydid-look closely at the front leg and you'll see an oval opening...this is where the ear is located! Ears are located on the two front legs and are used to listen for mates and predators such as bats. Bats can locate and prey upon the katydid by their songs, so katydids may pause their song in response to bat echolocation calls.





This sparkling little jewel is the Virescent Green Metallic Bee. These tiny bees nest socially, but do not make honey, although they are a pollinator of some plants. A female will dig a tunnel in the bare soil or in a dry bank for the colony. The entrance of the tunnel is then guarded by a single bee who will plug the entrance hole with its body until another bee wants in or out. You can observe the guard bee's head right at the entrance as it prioritizes who will enter or exit. Bees returning with pollen will be allowed to enter before any of the bees wishing to exit will be allowed out. The bee pictured here is the male-he can be distinguished by his striped abdomen.


I was pleasantly surprised when I blew up this image. Such a pretty sight as it appears this tiny little bee is holding the stamen of this little flower known as "blue-eyed grass" as if he is smelling it! He is not actually smelling the flower, and he isn't really a bee.  The insect is actually a Hover Fly. (He gets his name because of the way he can hover in mid-air and dart quickly around, and also fly backwards). This species is a "bee mimic".  His coloration and movements mimic those of bees. This insect cannot sting in any way, but may mimic the stinging action of a bee or wasp by pushing the tip of his abdomen into your fingers if he is caught and held. (Another of nature's mechanisms to ward off potential dangers). This tiny hover fly is beneficial because it is an important flower pollinator and also because their larvae will eat many pests in gardens and crop fields.

The pattern on this one reminds me of something that would be painted on a '70's volkswagon bus! This is the very pretty Ailanthus Webworm Moth. While feeding, he doesn't look anything like a moth  for a reason. He mimics a brightly colored beetle by wrapping his wings tightly around his body. This is another of nature's defensive techniques-pretty cool! This moth's name comes partly from the name of the tree that it likes to feed on-the Ailanthus Allissima (Tree of Heaven). This weedy-looking tree was introduced by central and South America to the United States back in the 1700's and now can be found growing wild just about anywhere, even in the cracks of sidewalks or growing out of old abandoned buildings.  Lucky for us this elegant little insect has taken a liking to this very invasive tree!  The Ailanthus Moth was originally an exotic species that was imported into the U.S. from China for the silk industry in the 1800's.  During the caterpillar stage, they spin silky webs within the leaves and they were raised to produce a coarse grade of silk. 






Cicadas Beware!
The following pictures that I'm including in my "Color Me Beautiful" post are anything but beautiful...in fact, they are downright terrifying. I am including them here because of all the cicada activity going on this time of year. 


I was photographing some birds when I heard a loud buzzing and big commotion in the leaves of a branch just above my head. I looked up and witnessed a Cicada Killer paralyzing and capturing a cicada. 


For those that have never seen one, a Cicada Killer is a very large wasp that digs a burrow in well-drained soil in areas that are largely exposed to full sunlight. Their evacuations  begin shortly after the cicadas begin singing. These large wasps look very intimidating, but they normally pose little threat to humans. The males cannot sting, but may dive-bomb people's heads as they display territorial behavior. The females are not aggressive and will rarely sting, but if intentionally provoked they can inflict a painful sting.


The following pictures show how a female captures her prey and then transports it away to her burrow. Some of the pictures are a little blurry due to the fast motion of the cicada killer during the attack:


This first picture shows the female flying in like a torpedo, claiming its victim by inflicting a sting that  instantly paralyzes the unsuspecting cicada.















The picture above and below show the cicada killer flipping the victim over and straddling it. This is the usual way in which a cicada is prepared before being transported away.



This was the last picture I took before the killer carried the cicada away. The female will glide with its victim and either climb another tree and glide again, or drag it (or both) until it reaches its burrow. The paralyzed (but alive) body is placed in a "cell" within the burrow were she will lay an egg on it. Within a couple of weeks, the egg hatches into a larvae and it will feed on the cicada and develop into the next stage (pre-pupa). It will remain in this stage the remainder of the winter and then emerge the following summer where the cycle is repeated.

The cicada killer is beneficial because it controls the cicada populations.




Tuesday, August 3, 2010

Got Milkweed?

While meandering along the edges of Lake Logan today, I noticed numerous bright, black and orange-colored bugs that seemed to be congregating on the milk weed plants. (Milk weed is the 3-4 foot tall plant that is commonly seen throughout the summer, with the big green seed pods that open up in the fall releasing seeds that float around on fluffy white parasols.) It turns out this particular insect is the Large Milkweed Bug. This bug is one of the few insect species that can tolerate the toxicity of the milkweed plant. When the bug feeds on the sap of this plant, the toxic compounds cause it to have a very bad taste, thus discouraging predators. For instance, once a bird eats a milkweed bug, the experience may deter him from doing it a second time. The bright coloring of this insect seems to display a warning to would-be predators. Even the beautiful monarch butterfly is protected by this "warning flag" in the natural world because of his coloring, (the color being very similar to the milkweed bug). As a caterpillar, the monarch also feeds on the milkweed plant, thus consuming the poisonous resin. Birds can become sick after eating too many monarchs so they learn to avoid insects with this coloring. This strategy is called "aposematism", and is employed by many organisms in nature. This defense can also be displayed through odor, shape or sound to avoid being eaten. Interestingly enough, the viceroy butterfly has evolved to look enough like a monarch that predators will leave him alone too! I love discovering these fascinating survival adaptations that are necessary in the animal kingdom!



The picture below shows how the milkweed bug penetrates the skin of the milkweed pod to access the seeds inside. As an adult, they utilize their long, sucking, tube-like mouth parts (proboscis) to access the nutritious seeds, while as a nymph they must feed on the surface of the green pod or from the leaves of the plant.


I find this picture fascinating! Here is a cluster of milkweed bug nymphs, which are very, very small. They are very brightly colored just like the adult even at this primary stage of their life. You may assume the larger one is the parent, but it is actually a nymph too! They go through 5 stages before they reach maturity. The stages are called "nymphal instars". Each time they molt, or progress to the next stage they become a little larger and more developed. The larger bug is simply in a later stage than the tiny ones-you can see it now has black "wing buds".  You may wonder why they are all piled up together.  Well, if you remember, their "warning coloration" fends off possible predators, so the more they cluster together, the brighter and more loudly they display this message!
As I was observing this group, the little nymph on the right side that is looking at the bigger nymph seemed to make a gesture with his actions, and the bigger one perked up and lifted his antennas.  Then the little one hopped over to join him. I don't know if this actually was a form of communication between them, but is was very interesting to watch! 

Another interesting thing I witnessed: while two adults were mating, another male came inching closer and closer and finally rushed in and knocked the other male away from the female, had a very quick rumble with him and instantly assumed the position that the previous male had occupied. The first male scurried away. I found that interesting enough to mention! Maybe I spend too much time creeping through the milkweed? (I had pictures of this too, but I didn't realize my batteries quit working on my flash, and the photos were too dark).