The Natives are restless and, like their human counterparts, their land is being taken from them. I’m not speaking of the Algonquin, Sioux or Navajo. I am speaking about tribes with names like Megachilidae, Colletidae, Osmia, and Bombus. These are tribes of the Native bees of North America. They have lived here for centuries prior to the invasion of the European interlopers, the Honey bee. There are somewhere between 3500 and 4000 species of Native bees in North America. That means that all pollination done in North and South America prior to the 1600’s was accomplished by these little known creatures.
They are cataloged and typed by several different names. Sometimes they are collectively called “pollen bees” because they carry far more pollen than honey bees. They are also known as “solitary bees” because they do not form large colonies. Each female develops her own nest without honey stores or workers. They are largely invisible to the average person, but of huge significance to the world. There are so many different types of these Native bees that it is hard to talk about them all at once. But there are a few simple facts that are relative to most.
Perhaps most importantly, Native bees are highly efficient pollinators. They often do the lion's share of pollinating crops, although this is not always recognized or appreciated. They have a number of advantages over honeybees as pollinators.
• Many are active early in the spring, before honey bee colonies reach large
size.
• Native bees are active earlier in the day and later in the afternoon than
honeybees, thus providing more pollination time.
• Native bees tend to stay in a crop rather than fly between crops, providing
more efficient pollination.
• Native bees seldom forage more than a couple of hundred yards from their
nest, whereas Honey bees may travel many miles.
• Because they fly faster than honeybees, they can pollinate more plants.
• Unlike honeybees, the males also pollinate the crop.
• Native bees are usually gentle, and do not sting since they have no honey
stores to defend. When they do sting, it is mild.
• Many native bees do not get disoriented in greenhouses.
Because of these differences, many Native bees are far more efficient pollinators than honey bees. Some experts suggest they accomplish more than 100 times what the Honey bee does. For example 250 Mason bees can pollinate one acre of apples. The same job would generally require a honeybee hive of about 20,000 bees.
Native bees have been shown to increase crop yields when they are present. Over 50 species of native bees specialize in plants such as watermelon or sunflower and over 80 species have been shown to be involved in berry crop pollination in Maine and Massachusetts. Native bees tripled the production of cherry tomatoes in one study in California. Many of these crops simply would not exist without native bees.
Often, growers don't realize how much pollination is performed by native bees. Signs of inadequate pollination are often misinterpreted as weather problems or disease. In one study it was found that of the 1700 bees trapped, only 34 were honeybees. This means that Native bees were performing almost all of the pollination in that area. Experts suggest that the economic value of pollination by Native bees greatly outweighs the traditional value of honey and wax produced by honeybees.
The drastic decline in feral and domestic honey bees has made it even more important to conserve and study wild bee populations.
The number of Native bees has also declined, but the reasons for these declines appear to be different from honey bees and are not well understood. Though some Native bees can be managed and used in commercial agriculture, most of them are regional. We do not know enough yet about their biology to know why they are declining, or how to manage them effectively.
So the fading drum beat of declining natives is once again affecting the North American continent. Likewise there may be serious consequences to the conqueror. However, if we can understand and preserve these native tribes, we may, at the same time, better feed the world. Towards this end biologists at Mesa State College will be collecting, identifying and attempting to culture local species of native bees in the future.
Friday, October 9, 2009
Monday, October 5, 2009
ART AND SCIENCE
Science is uniquely concerned with physical things. Historically science is born of questions such as: How many are there? Why do apples fall down? How does a falling thing fall? What shape is it? How big is it. How much does it weigh? Why does that object act that way? This requires scientists to restrict their attention to a limited single object and study that one object carefully.
This study may require tremendous physical skill and special techniques. The scientist may have to invent new methods and perfect new skills to conduct his studies. Often numerous studies are done which simply attempt to establish a pattern or direction. But from this careful, and sometimes lengthy, study the scientist attempts to distil some kind of general understanding about the object or event that they have studied.
This general understanding is sometimes called a theory. As it becomes more reliable and useful, it is sometimes is called a Law. These general ideas can then be used to compare other similar objects, evaluate the theory further, and make predictions about events under certain conditions.
But the overall conclusion is that scientists tend to begin with some real-world physical object or phenomenon and conclude with a general idea. They turn the world of reality into the world of imagination and thought.
In contrast, art appears to be concerned with ideas. Much of art, including visual art, music, language arts and performance, appears to be born from such matters as: religious concepts, political movements, cultural characteristics, imaginary events or social ideals. This requires the artist to restrict their attention and focus on a specific idea they wish to explore.
This exploration may require an extended period of time to consider all the ramifications of the idea they wish to explore. This is followed by an extended period of time when the artist may have to invent new methods and exert considerable skill in his chosen medium to produce a model. Often the artist may make several models or attempts to capture the ideas he is contemplating.
In the end the artist creates a physical object which represents his view of the purely ethereal idea he has been contemplating. The important thing is that the end product is a function of the physical world. It may be visual, audible, or palpable; but it is real. This object can then be used to test the accuracy of the artists (and societies) understanding of the idea, explore the ramifications of the idea, explain the idea more fully to others, or even test the truthfulness of the idea.
But the overall conclusion is that artists tend to begin with some non-physical idea and conclude with a real object or physical manifestation that can be detected by the senses. They turn the imaginary world of ideas into reality.
It seems that both groups of people are concerned with understanding our world, arriving at some form of truth and increasing understanding. Even the skills and talents involved are very similar in a general sense. What appears significantly different is that they initiate their mental journeys from separate starting points.
Unfortunately, because of their opposite trajectories, scientists and artists often see themselves as in conflict. Understanding similarities enriches each field significantly. This can be especially powerful in educational endeavors where numerous studies and pilot projects have shown that using one approaches to study the other is especially effective.
For example, having students write about math or science has increased understanding for many students. Writing computer programs that artistically animates scientific phenomenon has proven animate to be an excellent learning tool. The discipline of assigning an artist to explore a specific scientific concept in an art class leads to greater understanding of both art and science.
The world appears to need fewer engineers and poets, and far more people who understand the relationship between ideas and objects. The creation of ideas has an effect on the physical world. The creation of objects has an effect on the creation of ideas.
This study may require tremendous physical skill and special techniques. The scientist may have to invent new methods and perfect new skills to conduct his studies. Often numerous studies are done which simply attempt to establish a pattern or direction. But from this careful, and sometimes lengthy, study the scientist attempts to distil some kind of general understanding about the object or event that they have studied.
This general understanding is sometimes called a theory. As it becomes more reliable and useful, it is sometimes is called a Law. These general ideas can then be used to compare other similar objects, evaluate the theory further, and make predictions about events under certain conditions.
But the overall conclusion is that scientists tend to begin with some real-world physical object or phenomenon and conclude with a general idea. They turn the world of reality into the world of imagination and thought.
In contrast, art appears to be concerned with ideas. Much of art, including visual art, music, language arts and performance, appears to be born from such matters as: religious concepts, political movements, cultural characteristics, imaginary events or social ideals. This requires the artist to restrict their attention and focus on a specific idea they wish to explore.
This exploration may require an extended period of time to consider all the ramifications of the idea they wish to explore. This is followed by an extended period of time when the artist may have to invent new methods and exert considerable skill in his chosen medium to produce a model. Often the artist may make several models or attempts to capture the ideas he is contemplating.
In the end the artist creates a physical object which represents his view of the purely ethereal idea he has been contemplating. The important thing is that the end product is a function of the physical world. It may be visual, audible, or palpable; but it is real. This object can then be used to test the accuracy of the artists (and societies) understanding of the idea, explore the ramifications of the idea, explain the idea more fully to others, or even test the truthfulness of the idea.
But the overall conclusion is that artists tend to begin with some non-physical idea and conclude with a real object or physical manifestation that can be detected by the senses. They turn the imaginary world of ideas into reality.
It seems that both groups of people are concerned with understanding our world, arriving at some form of truth and increasing understanding. Even the skills and talents involved are very similar in a general sense. What appears significantly different is that they initiate their mental journeys from separate starting points.
Unfortunately, because of their opposite trajectories, scientists and artists often see themselves as in conflict. Understanding similarities enriches each field significantly. This can be especially powerful in educational endeavors where numerous studies and pilot projects have shown that using one approaches to study the other is especially effective.
For example, having students write about math or science has increased understanding for many students. Writing computer programs that artistically animates scientific phenomenon has proven animate to be an excellent learning tool. The discipline of assigning an artist to explore a specific scientific concept in an art class leads to greater understanding of both art and science.
The world appears to need fewer engineers and poets, and far more people who understand the relationship between ideas and objects. The creation of ideas has an effect on the physical world. The creation of objects has an effect on the creation of ideas.
Friday, September 25, 2009
CHOICES
I am working on several projects besides my day job right now. One of them is a fantasy novel and another is a music CD about Adam and Eve and the garden. I write on my novel everyday. I wrote and arranged all the music last year so I basically only work on the music about once a week in the studio.
In my novel I just wrote a scene last night in which a person is offered everything they could possibly want, riches, fame , adulation, power. On the other hand they could choose a canteen of cold water and a sword. The soldier, knowing her own values, chose the canteen and sword.
In the night I awoke (literally) with the realization that was exactly the choice placed before Adam and Eve. This thought has haunted me all day as I have wondered in my mind, in between classes and at slow moments, if I know who I am and what I would choose. Do I make music and write for fame, adulation, riches and power? Or are words and music my canteen and weapon? What is worrying me is, I am not sure I know.
In my novel I just wrote a scene last night in which a person is offered everything they could possibly want, riches, fame , adulation, power. On the other hand they could choose a canteen of cold water and a sword. The soldier, knowing her own values, chose the canteen and sword.
In the night I awoke (literally) with the realization that was exactly the choice placed before Adam and Eve. This thought has haunted me all day as I have wondered in my mind, in between classes and at slow moments, if I know who I am and what I would choose. Do I make music and write for fame, adulation, riches and power? Or are words and music my canteen and weapon? What is worrying me is, I am not sure I know.
Thursday, September 10, 2009
SWEET MEDICINE
In 1976 my wife and I were involved in a head-on collision that left me semi-scalped from my eyebrows to about half-way back on my head. It looked pretty awful but was actually not a serious injury. The doctors sent me home with instructions to apply hydrogen peroxide to the wound several times each day to avoid infection.
Hydrogen peroxide is a compound that has two molecules of hydrogen and two molecules of oxygen. That makes it the same as water, except that it has one extra oxygen. When it is applied to injured human tissue, it is exposed to an enzyme that liberates the extra oxygen, leaving water and a single oxygen floating around. That single oxygen is highly reactive and attaches itself to any bacteria in the wound and damages the bacteria’s cell membrane, killing the bacteria. The oxygen that is released, however, causes the tissue to foam in a dramatic way.
On the first morning after the accident my young children were talking to me about what had happened as I applied the hydrogen peroxide to my forehead. They watched in horror as my entire forehead foamed up with hydrogen peroxide. They were both fascinated and appalled. The fascination proved to be the bigger factor as they insisted on being present for every subsequent application. I became the only Dad they had ever heard of with a foaming head. In fact, they asked if they could bring their neighborhood friends to watch. Sensibly, I did not allow this.
“But what does hydrogen peroxide have to do with honey?” you ask. It turns out that honey has the necessary components to produce miniscule amounts of hydrogen peroxide over an extended period of time. Honey is about 30% glucose. But it also contains glucose oxidase, an enzyme from the stomach of bees that is secreted into honey by the bee. This enzyme, in the presence of oxygen and water, can break glucose down into gluconic acid and hydrogen peroxide.
However, this enzyme does not function in honey because the pH of honey is too low. Honey generally has a pH reading somewhere between
3 and 4.5, and glucose oxidase requires a pH of about 6. Also, for glucose oxidase to function requires at least 2300 parts per million (ppm) of sodium to be present. Honey usually has only about 30 ppm. So good clean honey, stored in a proper container, is stable with no reaction occurring.
Human tissues contain an abundance of sodium, and the pH is generally slightly more than 7. If honey is applied to injured human tissue, the pH is slowly raised where the honey comes in contact with the injured skin. The abundance of salt in the body combines to activate the glucose oxidase. This causes the honey to produce minute doses of hydrogen peroxide over an extended period of time, directly to the place where it may be needed to combat possible infection. However, the honey isn’t as fun to watch as the hydrogen peroxide because you miss the foaming part.
Honey is also a supersaturated sugar solution and will not support the growth of bacteria because it pulls the water out of any bacteria present. Honey’s low pH also creates an environment that inhibits most bacteria growth. Finally, some honey has been shown to contain anti-bacterial compounds isolated from the floral nectars. In all, honey can be used as a home remedy for dressing wounds.
As you might guess, honey varies in its medicinal effectiveness, depending on the floral source of the honey and other factors such as water content, glucose content, glucose oxidase content, and other parameters. Some honeys, such as Manuka Honey from New Zealand, have greater medicinal properties than others. This lack of uniformity is one reason why honey isn’t used more aggressively in regular medical treatment.
Well, that, plus the fact that the honey is far less exciting to watch than plain hydrogen peroxide!
Saturday, September 5, 2009
HEALTH CARE
I’ve been trying to decide if I am healthy or not. Of course, I’ve been blind since the third grade, but it hasn’t really hampered me a lot. That’s because I wear glasses. Part of the health care industry I suppose. I have high blood pressure, but with the little pills I can still run for over an hour and climb to Hanging Lake. My left thumb aches now when I play the mandolin or guitar too much. But I always considered Ibuprofen the breakfast of champions.
So, if I am coping and working and being productive, am I healthy? I certainly don’t feel sick or diseased. So with all the discussion going on about fixing our health care system, I have been trying to decide if I need it. Just exactly what is the health care system?
So I Googled the definition and found several different ones, but most of them sounded something like this: the condition of being sound in body, mind, or spirit; especially: freedom from physical disease or pain. Having looked this up before, I wasn’t too surprised. The problem with this definition is that it hardly anyone I know qualifies. I mean, is near- sightedness a disease? How about guitar induced inflammation? It hurts.
So if health is defined more or less as the absence of disease, what then is disease? So I looked that up. “Disease is a condition of the living animal or plant body or of one of its parts that impairs normal functioning and is typically manifested by distinguishing signs and symptoms.” In other words, disease is the state of being unhealthy.
I find it odd that a country would spend such a huge amount of money on an industry that cannot be defined accept in terms of itself. No one seems to know what the health care industry is for.
Is it to keep us from dying? That isn’t possible. The earth is a finite resource and cannot support an infinite number of living things of any kind. Is the health care system about preventing disease? That too is impossible. For one thing death comes at the hand of disease and since death comes to all men we cannot prevent disease.
More significantly not all diseases are alike. Infectious diseases are probably a part of biology. From the earliest imagine life form, living things have required a surface to live on. When surface area became crowded the next most logical step was to simply live on top of some other living thing. And living things living on living things is a perfect description of infectious disease. It’s just biology. But there are other kinds of disease such as physiological diseases. These are diseases that are the result of mechanical type malfunctions in machinery, whether due to use or simply being constructed incorrectly by the blind forces of development. In these types of disease cells may go awry, systems may malfunction, parts may not fit, or accidents happen that misalign pieces.
Perhaps the reform we need is to define what the Health Care Industry really is. How can we tell if something is broke if we don’t know what it does? How can we know how to fix something if we don’t know what it does? Or maybe some people really don’t care what it is supposed to do. Maybe there are other reasons to dabble with a third of the nation’s gross national product.
So, if I am coping and working and being productive, am I healthy? I certainly don’t feel sick or diseased. So with all the discussion going on about fixing our health care system, I have been trying to decide if I need it. Just exactly what is the health care system?
So I Googled the definition and found several different ones, but most of them sounded something like this: the condition of being sound in body, mind, or spirit; especially: freedom from physical disease or pain. Having looked this up before, I wasn’t too surprised. The problem with this definition is that it hardly anyone I know qualifies. I mean, is near- sightedness a disease? How about guitar induced inflammation? It hurts.
So if health is defined more or less as the absence of disease, what then is disease? So I looked that up. “Disease is a condition of the living animal or plant body or of one of its parts that impairs normal functioning and is typically manifested by distinguishing signs and symptoms.” In other words, disease is the state of being unhealthy.
I find it odd that a country would spend such a huge amount of money on an industry that cannot be defined accept in terms of itself. No one seems to know what the health care industry is for.
Is it to keep us from dying? That isn’t possible. The earth is a finite resource and cannot support an infinite number of living things of any kind. Is the health care system about preventing disease? That too is impossible. For one thing death comes at the hand of disease and since death comes to all men we cannot prevent disease.
More significantly not all diseases are alike. Infectious diseases are probably a part of biology. From the earliest imagine life form, living things have required a surface to live on. When surface area became crowded the next most logical step was to simply live on top of some other living thing. And living things living on living things is a perfect description of infectious disease. It’s just biology. But there are other kinds of disease such as physiological diseases. These are diseases that are the result of mechanical type malfunctions in machinery, whether due to use or simply being constructed incorrectly by the blind forces of development. In these types of disease cells may go awry, systems may malfunction, parts may not fit, or accidents happen that misalign pieces.
Perhaps the reform we need is to define what the Health Care Industry really is. How can we tell if something is broke if we don’t know what it does? How can we know how to fix something if we don’t know what it does? Or maybe some people really don’t care what it is supposed to do. Maybe there are other reasons to dabble with a third of the nation’s gross national product.
Saturday, August 15, 2009
DEBT IS BONDAGE
(I initiated this blog to discuss science ideas and concepts. However, after taking the summer off, I find that science education does not seem to be the most pressing issue in my mind. I apologize if you came here for scientific enlightenment, but this entry will deal with a more pressing issue; FREEDOM.)
Debt is bondage. When you owe money on your car you are not free to buy another car. When you owe too much on your credit card you are not free to use your credit card for an emergency expense. When you owe money on your home you are not free to quit your job or move to another state. For a long time Americans have been prosperous enough to work around these limitations to a degree, but it does not change the fact that when a person owes money they are not totally free.
The crime that has been committed by the elected representatives in this country, for more than fifty years now, has been to slowly place the nation into debt. This debt has been accumulated for multiple reasons, many for seemingly good and kind humanitarian reasons. The reasons do not matter. We have spent money we did not have and borrowed to make up the difference. We can argue about the causes of these actions and the needs that have been addressed, but the bottom line is that now the United States is massively in debt. Now the United States is in bondage.
We would never have allowed a foreign invader to put us in bondage. But we have sold our liberty, and the liberty of our children, for questionable causes. Of course it is good to care for the poor. It is admirable to respect our elders. It is compassionate to care for the sick. But if I borrow money to donate to the needy, however that is defined; I will soon be a slave to my creditors.
Every responsible citizen knows they cannot have everything they want. Every successful household has discussions concerning what is wanted and what is needed. This is how reasonable people run their lives to avoid slavery and bondage. Can it really be true that different economic realities and rules exist for governments and world order? Of course not.
The argument has been for many years, and by every political party, that we need to be compassionate and we need to be efficient. Liberty has never been either. Liberty has been cruel and caused the death and suffering of millions who seek it. Liberty has always been messy and costly. Yet, among all men, it is the one attribute desired uniformly, regardless of culture, religion, or creed.
Americans may still be brave. But we are no longer free. We have allowed our elected representatives to again and again make foolish decisions that have left us debtors and in bondage. I do not know the motives of these many men and women who have participated. Some have resisted, but most have not. I will not say that they are wicked, evil, well meaning, idealistic, or selfish. It doesn’t really matter. The end result is that I am not longer a freeman.
The only sensible solution is the one every responsible person recognizes and applies in their life daily. Carefully manage our affairs. Do not spend what we do not have. Save some money for emergencies. Do not invest in new and risky ventures. Work hard and be frugal until the debt is paid. Deny one-self of many niceties in order to assure the necessities. Are there any candidates running for office today with these values and the ability to live by them when elected?
Debt is bondage. When you owe money on your car you are not free to buy another car. When you owe too much on your credit card you are not free to use your credit card for an emergency expense. When you owe money on your home you are not free to quit your job or move to another state. For a long time Americans have been prosperous enough to work around these limitations to a degree, but it does not change the fact that when a person owes money they are not totally free.
The crime that has been committed by the elected representatives in this country, for more than fifty years now, has been to slowly place the nation into debt. This debt has been accumulated for multiple reasons, many for seemingly good and kind humanitarian reasons. The reasons do not matter. We have spent money we did not have and borrowed to make up the difference. We can argue about the causes of these actions and the needs that have been addressed, but the bottom line is that now the United States is massively in debt. Now the United States is in bondage.
We would never have allowed a foreign invader to put us in bondage. But we have sold our liberty, and the liberty of our children, for questionable causes. Of course it is good to care for the poor. It is admirable to respect our elders. It is compassionate to care for the sick. But if I borrow money to donate to the needy, however that is defined; I will soon be a slave to my creditors.
Every responsible citizen knows they cannot have everything they want. Every successful household has discussions concerning what is wanted and what is needed. This is how reasonable people run their lives to avoid slavery and bondage. Can it really be true that different economic realities and rules exist for governments and world order? Of course not.
The argument has been for many years, and by every political party, that we need to be compassionate and we need to be efficient. Liberty has never been either. Liberty has been cruel and caused the death and suffering of millions who seek it. Liberty has always been messy and costly. Yet, among all men, it is the one attribute desired uniformly, regardless of culture, religion, or creed.
Americans may still be brave. But we are no longer free. We have allowed our elected representatives to again and again make foolish decisions that have left us debtors and in bondage. I do not know the motives of these many men and women who have participated. Some have resisted, but most have not. I will not say that they are wicked, evil, well meaning, idealistic, or selfish. It doesn’t really matter. The end result is that I am not longer a freeman.
The only sensible solution is the one every responsible person recognizes and applies in their life daily. Carefully manage our affairs. Do not spend what we do not have. Save some money for emergencies. Do not invest in new and risky ventures. Work hard and be frugal until the debt is paid. Deny one-self of many niceties in order to assure the necessities. Are there any candidates running for office today with these values and the ability to live by them when elected?
Sunday, August 2, 2009
LUNCH WITH BLOODSUCKERS
When I was young I reveled in Edgar Rice Burroughs “Tarzan” books. I don’t know if I read all twenty three or not, but I read a lot of them. And while I didn’t exactly know what a tsetse fly was then, I knew it was dreaded and carried deadly disease. So I was excited years later when I found myself in a class studying African sleeping sickness, transmitted by the “dreaded tsetse fly”.
Tsetse flies are large flies, about the size of our western horsefly, that are only found in Africa. They feed during the day, and both males and females feed exclusively on blood. In feeding they transmit a microscopic parasite called a Trypanosome that in turn causes African Sleeping Sickness.
Now, there is a great fascination by young boys, of almost any age, with gory things like blood sucking. It is a recent phenomenon that so many young girls and women have become interested in blood sucking.
One fascinating subject is how a blood sucking insect finds its food. It is surprising to me how little is known about the insect food-selection process.
It quickly becomes apparent that the simple act of getting lunch, is actually a multistep, multisensory, complex, interaction of senses, behaviors and environmental cues for an insect. For example, how does an insect even know when it’s time to eat? It is generally thought that mosquitoes feed at dusk. But how do they know when it is dusk? Is it by day length and light? That certainly seems to be one cue. However, mosquitoes kept in captivity will become restless, act “hungry”, and feed when kept in constant light conditions, if presented with other cues. Then there are those species that feed at two in the morning; you know the one that wakes you up with that dreaded buzzing in your ear.
Blood sucking insects can’t really expect dinner to remain in a fixed position until the next meal, like a McDonald’s resteraunt. So how do they locate a blood source? It is commonly thought that they follow a carbon dioxide plume, but carbon dioxide is actually only an exciter. The mosquitoes get excited whenever the concentration of carbon dioxide changes, whether it increases or decreases. They don’t follow the carbon dioxide as much as they react to it. Since carbon dioxide levels fluxuate continually, why don’t they react then? When presented with several selections on the menu, why do they always pick me? How do they decide between an arm and a leg, and which position on the arm is most attractive? The questions seem endless.
This is all complicated by the fact that there are over 3000 species of mosquito in the world and each has its own peculiar time, place, and preferred host for feeding.
Now for the amazing part: only half of mosquitoes take a blood meal, the females. The males feed entirely on plant sources of sugar. Females only require blood during reproduction. The rest of the time she lives on plant nectar also. So various floral and plant sources provide the great bulk of day-to-day mosquito energy needs. Yet our knowledge of when, where, why, and how they seek floral nectars is minimal.
Better understanding of the feeding habits of blood sucking insects would aid in the development of better control strategies, and improved disease prevention since most blood sucking insects are capable of transmitting disease. Answering questions like “How do tsetse flies know when it is dinnertime?” and “What flowers do mosquitoes prefer?” are what biologists do.
I have a couple of ideas about how to answer these questions. If you’re interested, wait until you are moved upon by some mysterious change in the carbon dioxide concentration and give me a call. We’ll do lunch.
Tsetse flies are large flies, about the size of our western horsefly, that are only found in Africa. They feed during the day, and both males and females feed exclusively on blood. In feeding they transmit a microscopic parasite called a Trypanosome that in turn causes African Sleeping Sickness.
Now, there is a great fascination by young boys, of almost any age, with gory things like blood sucking. It is a recent phenomenon that so many young girls and women have become interested in blood sucking.
One fascinating subject is how a blood sucking insect finds its food. It is surprising to me how little is known about the insect food-selection process.
It quickly becomes apparent that the simple act of getting lunch, is actually a multistep, multisensory, complex, interaction of senses, behaviors and environmental cues for an insect. For example, how does an insect even know when it’s time to eat? It is generally thought that mosquitoes feed at dusk. But how do they know when it is dusk? Is it by day length and light? That certainly seems to be one cue. However, mosquitoes kept in captivity will become restless, act “hungry”, and feed when kept in constant light conditions, if presented with other cues. Then there are those species that feed at two in the morning; you know the one that wakes you up with that dreaded buzzing in your ear.
Blood sucking insects can’t really expect dinner to remain in a fixed position until the next meal, like a McDonald’s resteraunt. So how do they locate a blood source? It is commonly thought that they follow a carbon dioxide plume, but carbon dioxide is actually only an exciter. The mosquitoes get excited whenever the concentration of carbon dioxide changes, whether it increases or decreases. They don’t follow the carbon dioxide as much as they react to it. Since carbon dioxide levels fluxuate continually, why don’t they react then? When presented with several selections on the menu, why do they always pick me? How do they decide between an arm and a leg, and which position on the arm is most attractive? The questions seem endless.
This is all complicated by the fact that there are over 3000 species of mosquito in the world and each has its own peculiar time, place, and preferred host for feeding.
Now for the amazing part: only half of mosquitoes take a blood meal, the females. The males feed entirely on plant sources of sugar. Females only require blood during reproduction. The rest of the time she lives on plant nectar also. So various floral and plant sources provide the great bulk of day-to-day mosquito energy needs. Yet our knowledge of when, where, why, and how they seek floral nectars is minimal.
Better understanding of the feeding habits of blood sucking insects would aid in the development of better control strategies, and improved disease prevention since most blood sucking insects are capable of transmitting disease. Answering questions like “How do tsetse flies know when it is dinnertime?” and “What flowers do mosquitoes prefer?” are what biologists do.
I have a couple of ideas about how to answer these questions. If you’re interested, wait until you are moved upon by some mysterious change in the carbon dioxide concentration and give me a call. We’ll do lunch.
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