Sunday, November 28, 2010

The Liquidator

This title may bring to mind a violent character in a mafia movie, but the term "Liquidator" also  accurately describes the feeding behavior of this lovely but deadly orange invertebrate. Meet the Assassin Bug! This particular one is a nymph, meaning he has not yet reached maturity. They go through different growth stages before becoming an adult. His physical appearance will change somewhat and he will also grow wings by the time he reaches his final stage of maturity.

So what is so intimidating about the behavior of this orange, spiny creature? Well, the following is proper dining etiquette according to this species:

The Assassin Bug will either lie in wait to ambush his prey or will stalk it, and then aggressively grab it with its powerful forelegs and plunge its "beak" (proper word is rostrum) into the unfortunate prey's body, pumping a powerful dose of lethal toxin into the tissues, which paralyzes the victim, then liquefies his insides. The Assassin Bug then guzzles up the gooey goodness through the same straw-like tube that he used to impale the victim with. Depending on the size of dinner, the Assassin Bug may feed for up to an hour to get every last bit of ooze. (Ahh, good to the last drop...wait, isn't that a Maxwell House slogan?) If that thought isn't bad enough, keep in mind that this insect is not afraid to attack something much bigger than itself! The potent poison is capable of liquefying a small insect in as little as 3 seconds and can even "do the job" on a very large caterpillar in as little as 7 or 8 seconds!

As I stated above, this nymph will change somewhat in appearance, but most Assassin Bugs share some general elongated head, narrow neck, long legs, and the prominent tube for feeding (rostrum). The rostrum can be a surprising weapon, containing tiny needles (stylets) that are used to puncture the food source, but while not in use it is held curved up toward the underside of of the body. The end of the rostrum is often held into a groove called the prosternum.  Notice how in some pictures the rostrum is tucked under, and other times, during hunting, it is swung forward. Interestingly, the insect can rasp the rostrum against ridges in the prosternum to produce sound--a tactic often used as an attempt to deter predators. If this warning doesn't work, the agitator receives a quick, painful stab.

Notice the many spines present on the nymph stage. Magnification shows tiny stiff hairs at the top of each spine. I am guessing this is a defensive characteristic for this young insect. It looks like he means business at both ends!! Abdominal dorsal spines are not present on the dorsal surface of the adult, and the adult's abdomen becomes more flattened.

There are thousands of species of Assassin Bugs that live in fields and forests world-wide. Mexico, Central America, and South America even have a species that likes to co-habitate with humans, and they have been known to transmit a potentially fatal disease called "Chagas Disease". We don't need to worry about that here in our part of the United States though. There is, however, a species commonly called the "kissing bug," because it lurks around at night in homes and will bite humans on the lips! This one is not prevalent in our immediate area either, but lives in the more Southwestern part of the United States. Some assassin bugs kill specific insects

That being said, you should still respect the species we have in our area because although they are normally a slow-moving, mind-their-own-business type of bug, they will inflict a very painful defensive bite if handled carelessly. Their "bite" is actually the same process they use to kill their prey...they will stab your skin and inject the same toxin into your tissues that is used to paralyze and kill insects, and this could cause necrosis cells at the injured site, causing burning and pain initially, and then an itchy lump later. There may even be a few individuals that are sensitive to the bite and they may experience a swollen tongue, larynx or difficulty breathing (as in bee sting allergies).

I felt very fortunate to be able to observe this Assassin Bug nymph as he was walking and hunting along the tops of some Queen Anne's Lace blooms in a field at Clear Creek Metro Park. This was the first of this species I've seen, and I thought he was strikingly beautiful. I loved the way he kept his eyes on me the entire time that I kept my eyes (and camera) on him. He literally watched every move I made. He had a very slow, deliberate pace as he moved from petal to petal of the flowers, carefully moving one leg at a time. I'm not sure, but I would imagine this "stealth walk" decreases the chance of him being noticed by his potential prey. The following are a series of pictures I took just because I loved observing him...His steady eye never leaving mine! By the way, these insects are actually very beneficial in controlling harmful insect populations. They do much more good than harm regarding their impact on humans. 

It was kind of comical how he was observing me from behind this leaf.  I thought it was cute at the time, but maybe he was sizing ME up??

Looks like an aphid lunch!

The genus Pselliopus is distinguished by the black banded, bright orange bodies.  believe the species in this blog is the Pselliopus cinctus, which is very similar to Pselliopus barberi. (It is hard make a positive ID of a nymph, but these two species are the common ones found in the Eastern United States). The bands are black and white on the cinctus and orange and black on the barberi. Dennis Profant, Entomology and Natural Resources instructor at Hocking College helped me to identify this one because of the confusion between the similar species (there is yet another species that also has the same coloration, but is only found in the western states). Insect identification sure gets confusing...I'm sure glad I have Kaufman's Field Guide to Insects and an Entomology instructor as a friend!

Friday, November 26, 2010

There's gold in them thar weeds!!

Back in August while walking along a field, a tiny sparkle of gold near the ground caught my attention. This little glisten begged me for a closer look! Down on hands and knees, I discovered a gorgeous, yet odd-looking little creature that looked like a microscopic turtle with antennas! Just so happens this little insect is appropriately named the Tortoise Beetle. There are actually 1400 different species (many brightly colored) in North America, but this particular one is the Mottled Tortoise Beetle (Deloyala guttata).

This miniature wonder is no more than 1/4 inch in diameter and sports a cool, colorful "shell" adorned with brilliant metallic gold splotches. The gold is super reflective! This shield flattens out around the edges and becomes nearly transparent, perfectly concealing the head and legs much like that of a tortoise (hence the name). I think they appear like they are encased in glass. These insects live and feed primarily on plants in the morning glory and bindweed family. The adults will spend their life among these plants and will lay eggs on the underside of the leaves. The larvae will hatch after a couple of weeks and they too, will immediately begin feeding on the leaves of the plant.

Interestingly, the larvae of the tortoise beetle carries a shield of a different kind on its back...they have spiny bodies and a hooked abdomen that serves to excrete and deposit large amounts of excrement (poo), which they will carry around on their back for camouflage. This excrement sticks to the back, along with the skins that are shed during molting, creating quite an unsightly appearance that may cause prey to look elsewhere for a meal. (These little critters create quite a disgusting image with all that crap on their back). This protective barrier is called a "fecal shield," and they will continue this masquerade until they reach the adult stage.

The larvae will continue to feed throughout the summer until they mature to adults, and will then overwinter in the debris at the base of the plant, where they will emerge the following summer.

When summer arrives again, you can bet I will be crawling around the bindweed and honeysuckle vines looking for tiny holes in the leaves that will be evidence of the feeding tortoise beetles. They are not very tolerant when approached, and will fly away quickly, but I welcome the challenge to get a better photographic angle to capture the adorable face that is hidden under the transparent edge of that unique, "stained glass" shell!

Sunday, November 14, 2010

Mother Oak

A couple of days ago my husband and I had the good fortune of meeting up with well-known Naturalist, Jim McCormac. He met us at Rhododendron Cove, which is a beautiful nature preserve, and led us on an enjoyable and informative hike.  His passion for the outdoors was evident as he introduced us to the many birds, plants, insects and trees that thrive there.  His keen ear and knowledge of "everything nature" made it effortless for him to identify every audible vocalization along the way, whether it be a chirp, cheep, buzz, screech, trill, tick or twitter!

The three of us rambled along discussing the many things we encountered along the way as we enjoyed the warm temperatures and morning sun. Jim and Steve continued up the steep trail to view the rock formations and dense rhododendrons, but I decided to hang back and check out photo opportunities (specifically insects)!

The leaf-littered footpath quickly turned into a "road to enlightenment" for me as I came upon a huge oak tree that would prove to be more than just a solitary stand of timber. I sat down at her base to look and listen. I find that when I sit very still and watch with a "soft gaze," things start to come to life! This is how I like to discover the many living creatures that inhabit wherever I happen to be.

The texture of the bark suddenly began to reveal a microscopic world in full motion! It turns out this big, beautiful oak tree was serving as a sanctuary to various tiny, yet very significant organisms! I sat and observed the movement in the cracks and crevices of the thick textured bark, as well as where the trunk meets the damp soil beneath the leafy ground-cover.  All of the "tenants" of the tree seemed too preoccupied with their own business to pay any mind to who or what else happened to be lurking around. It was amazing that Mother Nature had provided this oak as a guardian and safe haven for some creatures, yet some of the others were utilizing it for a stalking and hunting grounds. Somehow in nature this delicate balance works flawlessly and is a prime example of the yin and yang of life! The amazing part is that all of this energy was going on just three feet above the ground...that is not to mention the importance of what is happening 60 or 70 feet above in the canopy where yet another ecosystem thrives involving many birds, mammals and other insects!

This blog includes my photographs, personal observations, and some research I did on the inhabitants of the lower portion of this living shelter I refer to as "Mother Oak".

This colorful, TINY insect (not quite the size of a grain of rice)  is an Orange and White Leafhopper. I believe this particular one may be Arboridia plena. There are around 20,000 different species and most are brightly colored with patterns of lines, patches and/or spots of various shades. There is a different leafhopper species for almost every type of plant. I have photographed other beautiful leafhoppers that I'll include in a future post.

This particular one seemed to be seeking shelter in a crevice in the bark. He was so tiny I actually had trouble getting the camera to focus on him. These are sap-sucking insects and they have very powerful, spiny back legs that allow them to jump very high and quick. They have especially large eyes for their size to provide excellent visual acuity, which aids in their survival.

An interesting note: They are also referred to as "sharpshooters" because they forcibly squirt out excrement in a fine stream of droplets from the huge volume of liquid they digest after feeding. Another interesting note is that they have sound-producing organs at the base of their abdomens. The "songs" that they produce are too faint to be heard by humans.

There were several other leafhoppers that were hopping around between the base of the tree and the dried leaves. I saw bright green ones and other striped ones, but they were too fast for photos!

Here is the most exciting thing I happened to see! I thought my eyes were playing tricks on me as I watched this little piece of bark seem to walk and around and nestle itself into a tight little crack of the oak's bark. It became still, and then another tiny clump of bark-like material began walking around, then another and another. I had never seen anything like it before! The moving clumps were very soft to the touch. Jim and Steve had just come down from the top of the trail and Jim informed me that it was a Lacewing Larvae. What the arrow is pointing to is the clump of lichen that the larvae has attached onto its back! This incredible behavior serves two purposes: It completely conceals them so they can stalk their next meal-and it certainly works! You absolutely would not notice this tiny insect if you were not paying VERY CLOSE attention! They move fairly slowly, so they are almost undetectable. Some larva may even cover themselves with their victim's dried remains so they can continue to stalk and feed without the next victim even becoming suspicious!

The other purpose this camouflage serves is to protect themselves. They blend so well into their surroundings that birds or other predators cannot detect them as food.

These tiny insects are actually ferocious predators and have a huge appetite, eating as many as 100 insects per day. They devour aphids, scales, mealybugs, mites, whiteflies, and insect eggs. They are considered very beneficial in this larval stage, as they help to keep those harmful populations down. They have sharp, curved jaws that resemble ice picks and can easily impale their prey. Aphids are a favorite, and they will grab one, suck out their juices, throw the remains to the side and grab another. They have even been given the name "Aphid Lion!"

These larvae will overwinter in the tree bark crevices or other protected places.

The adult Lacewing is a delicate, pretty insect with wings that resemble translucent lace. They feed mostly on pollen and nectar, and supplement their diet with some mites and aphids.

Here you can get a glimpse of this amazing insect! Jim pulled one of the clumps off the tree so we could get a look at what was underneath. As you can see, that clump of lichen is really packed around that tiny body! This one seemed really agitated being upside-down. His tiny legs were kicking like mad! His abdomen is what is visible, so his head is still hidden under the clump. When Jim returned him to the tree, he stuck to it like velcro and continued his journey upward! I was really excited to be able to witness this cool and unusual display!!

This strange-looking fellow's common name is Winter Firefly (Ellychnia corrusca). This is another insect I have never seen before! They are a bit larger than the common lightning bug. There were several of these fireflies deeply tucked inside the cracks and crevices of their huge "Oak shelter". They tuck their heads under, displaying what resembles a shield against their body, and will overwinter in the crevice, and will become active once again in March. Mating will take place in April and May.

Here is one of the Winter Fireflies who apparently has not picked out a suitable winter resting spot yet! This species is diurnal, which means they are active in the daytime (whereas the common firefly we know so well is active at night). The Winter Firefly is also a bit different, in that it is "fire-less". They are not bioluminescent like our night-loving fireflies. This species lack the light-producing organs. They are very active during the summer days and feed on flowers and sweet sap, but as temperatures cool, they become less active and begin to stay close to tree trunks where they will find refuge in the crevices throughout the cold winter months.

Here are a couple of other very small critters making the oak tree their home. The top tiny insect is labeled "Collembola". The common name is Springtail. There were several of these throughout the bark of the tree, and no doubt many more that went unnoticed among the leaves and soil. These insects have been around for 400 million years and are by far the most abundant insect in the world!  They can be found anywhere on earth and exist in the soil, moss cushion, fallen wood, grass tufts, ant and termite hills and tree bark...just about anywhere. There are some 6000 species worldwide and different species can survive extreme climates. There are some that can be found at 21,000 feet on Mt. Everest and even Antarctica, and still others that can be found in the volcanoes in Hawaii, surviving at 130 deg. F!

The insect gets its name from a curved organ on its ventral surface that it uses to propel itself up into the air. Their quick jump resembles that of a flea. They are so small you can hardly see them, but they do play an important role. They eat organic material (decaying vegetation, fungi, bodies or fragments of dead organisms, etc.) and this aids in microbial breakdown as well as in aiding the formation of soil and micro structures. In other words, they serve a vital part in the soil-making process. They are also a significant food source for beetles, spiders and other carnivorous invertebrates. I guess everything in nature, regardless how tiny, has a purpose!

I'm not completely sure, but I believe the spider is one of the Sheetweb Spiders. There are over 4000 species known and they are very small, shiny and many have ornamental abdomens. They are called Sheetweb Spiders because of the shape of their web. The different species build different types of sheet webs, but this particular species builds a very fine, almost invisible, non-sticky web on tree bark, the ground, on stones or plant material. It is difficult to tell from this picture, but there is a very fine web that just barely clears the crevices of the bark. It covered quite a large area.  These tiny spiders are very well camouflaged in their surrounding as you can see.  This species is one of the most common ballooning spiders...they can release a burst of silk into the air, which can carry them quite considerable distances.

I found this interesting-looking bug on a leaf on the ground. This may look like a small leaf on the surface of a larger leaf, but it is actually a Diamond-Backed Spittlebug (Lepyronia quadrangularis).  There are several different species of these  sap-sucking insects and they are best known for the frothy foam they produce as a nymph. The white froth is produced from ingesting liquids from plants, which are then secreted from their hind-end. The liquid is blown through abdominal openings, creating tiny bubbles that they use to cover themselves with by using their hind legs. This frothy mass of spittle is used to shield the nymph from predation, insulate it during cooler temperatures and prevent dehydration. Pictured is the adult spittle bug, and they are usually found in fields and meadows. This species usually lives cradled in leaf axils, and they prefer leaves with a wide axil. (The axil is the space between the stalk of a leaf and the stem to which it is attached). The adult will overwinter in swampy, protected areas. Notice this spittlebug is well camouflaged on this oak leaf; another example of how this mighty tree provides protection! This species of spittlebug is also referred to as a "froghopper" because it of its extreme jumping ability. It can even catapult itself higher and faster then grasshoppers and bush crickets!
The shape of the diamond-backed spittle bug even resembles a tree frog when the frog is at rest...below is a picture I took this past summer of a tiny  spring peeper resting on a leaf. When the frog's eyes were closed, the shape was incredibly similar to this spittlebug! They are even close in size. I guess that is an example of nature's mimicry!

It was fascinating to see so many different species who all occupied the same space and seemed to stay out of each other's way. I love viewing the macro world-there is so much to discover! I can't get enough of learning about the things that I find through my viewfinder, and it always makes me want to research and read as much as I can to better understand the different species and how they contribute to the big picture.  I try to make sure the information in my blog is as accurate as possible. Dennis Profant, Entomologist and Natural Resources instructor at Hocking College, is a huge help whenever I cannot identify something. He is such a valuable resource and like Jim McCormac, he is always eager to share his infinite knowledge!  By the way, if you aren't already one of Jim's followers (Ohio Birds and Biodiversity), you can see his blog here:
Dennis Profant also has a very interesting blog that he regularly posts. You can see it here: Field Biology in Southeastern Ohio