Munching on a Chemist

2005-11-08T22:07:00.000-05:00

Biotech Bugs: The Next Miracle

According to a press release from the U.S. State Department, genetically modified bugs could be the next “miracle” in the field of biotechnology. The two types of genetically modified insects under research are paratransgenic and transgenic insects. Paratransgenic insects are created by integrating a piece of DNA manipulated in the laboratory (referred to as the transgene) into the microbes that naturally inhabit their alimentary canal. Genes expressed in these microbes can alter the characteristics of the host insect. Transgenic insects are the product of the physical integration of transgenes into the chromosomes of an insect. The press release states:

“The successful application of GM insects could dramatically improve public health, particularly in developing countries, enhance agricultural production, and improve the natural environment, according to some scientists. It also could make one hesitate whether to hit a mosquito on one’s neck because it can fight rather than carry a disease.”

People may no longer look at insects as a nuisance, but rather a benefit to the world. The article also reports that scientists are working to develop a broad array of insects with new characteristics that could make them useful in fighting the spread of infectious diseases, controlling noxious weeds and insect pests, and producing pharmaceuticals. For example, honeybees can be genetically altered in a way that makes them resistant to diseases and parasites, and genetically engineered silkworms can produce industrial proteins for application in the creation of novel materials.

Besides their productivity, these genetically modified insects may carry a solution to the malaria, which affects about 300-500 million people and kills about 1 million every year according to the World Health Organization. It is interesting to see what will come out of this research, as this topic may have a dramatic impact on the world.

Further information on this topic is available in The Promise of Biotechnology

2005-11-08T19:49:00.000-05:00

Expansion May Spell the End for a Butterfly

Chinese cities have experienced phenomenal growth and expansion in the last twenty years, however this growth and expansion has caused harm to the environment. According to a recent article in China Daily, a rare butterfly in Nanjing, capital of East China's Jiangsu Province, is disappearing because the city's expansion is damaging the plant diveristy of the region. The butterfly, the Chinese Tiger Swallowtail, is only found in China and has been around for about 80 million years. Experts say that if no action is taken, the butterfly will be extinct in five years. According to Wu Qi, a researcher who has been exploring the butterflies:

“As Nanjing has grown, although green spaces have been included in the expansion, plant diversity has been ignored. Trees and flowers considered beautiful are planted in large numbers, while common and less colorful species are destroyed. The Chinese Tiger Swallowtail butterflylikes eating wild ginger, a plant which has disappeared rapidly during the city's development.”

The city has planted several trees, however these trees have only been planted for decoration; not to help the environment. It would be highly unfortunate for a species that has existed for 80 million years to become extinct because of the expansion of cities and a lack of concern from the government.

2005-11-08T17:38:00.000-05:00

Wasps Track Odors Better than Dogs

An article in the Philadelphia Inquirer gives details of the recent studies which have shown that wasps can be trained to track odors. In fact, in many ways they are superior to scent tracking dogs. In a matter of minutes, they can be introduced to a smell and trained to react to this odor by associating it with food. These studies have been conducted by the scientists at the University of Georgia and the U.S. Department of Agriculture.

“Researchers placed trained wasps in a specially crafted container, which they dubbed the Wasp Hound. When the target odor was introduced through a hole, the insects clustered around, triggering an alarm.”

The amazing ability of these wasps to react so strongly to an odor may be very beneficial to police forces. Wasps are a much less expensive alternative to dogs in addition to being much more sensitive to odors. They are even ten times more sensitive than some electronic devices used to track odors.

Wasps are also much more efficient than dogs. Their training can be done in less than six minutes, whereas dogs can take up to six months. They can be trained to track almost any smell that does not kill them. Overall, this could be a great advancement in the science of odor tracking by making it less expensive, more efficient and more accurate.

2005-11-08T10:51:00.000-05:00

Questionable mating practices of insects

In a recent study, the Australian Museum has discovered that some insects are practitioners of what is called traumatic insemination. Traumatic insemination is an uncommon way of mating in which the male pierces the female with its hypodermic genital and releases its sperm into the bloodstream rather than the genital tract. According to Nikolai Tatarnic of Sydney University, quoted in the Australian newspaper, The Age,

“it’s basically a strategy for the males to get past female resistance to mating.”

In fact, the males of a certain species of bugs had corkscrew-shaped genitals while the females of that species had corkscrew-shaped holes in the sides of their bodies, suggesting that this kind of mating factors into evolution. Mr. Tatarnic suggests that this could be indicative of an “evolutionary arms race” in which each gender of a species of insects develop one physical quality after another in an effort to gain an advantage in mating.

2005-11-08T10:32:00.000-05:00

The insect world does have a dark side…

While insects are in most cases beneficial, there are certainly those that none should deal with. This was a fatal lesson that Mariana Carmichael learned the hard way (although it was not her fault). As her husband Glaswegian James was driving her to a hospital in Johannesburg, South Africa, for her respiratory problems, the couple became involved in a car crash, in which their Cherokee Jeep subsequently rammed into an electricity sub-station. As it turns out, the ceiling of this sub-station housed a six square meter honeycomb home to 250,000 African killer bees. Witnesses were quoted in the British online newspaper, The Sun, as saying that

"the bees poured out like thick black smoke” and “covered them [i.e. James and Carmichael] so thickly” that it “looked as if the people were wearing jerseys.”

While Carmichael died on the spot, James was still conscious when firefighters arrived (the paramedics could not do anything until the firefighters hosed the bees away). According to a bystander and beekeeper Carl Meyer, just 100 stings from these bees can kill a human, and James was very lucky to be alive.
Apparently, these bees seem to be geared more toward killing rather than gathering honey; in addition to having a highly toxic sting, each bee, when it stings, releases a chemical that acts as a beacon for other bees to come and join in.

2005-11-03T21:14:00.000-05:00

High Toxicity Level of Pyrethroid Pesticides in Urban Streams

Toxic levels of pesticides were found in urban streams in Roseville, California. Originally, it was believed that these pyrethroid pesticides were only a problem in agricultural areas, but according to a study by University of California, Berkeley, Southern Illinois University and the Central Valley Regional Water Quality Control Board, the problem occurs in urban areas too. Pyrethroid pesticides are commonly used such as cotton, fruit and lettuce. The toxicity tests were conducted on Amphipods, which are tiny shrimp-like animals that are recommended for use in all toxicity tests by the Environmental Protection Agency. The study leader, Donald Weston said:

"Amphipods are a relatively sensitive group of animals, so this study is telling us that pyrethroids at these test sites are reaching levels where they can be lethal to sensitive species"

Studying the effect of these pesticides on such a sensitive creature may make the toxicity seem more exaggerated to humans, who are far less sensitive than these animals. However, it is also beneficial to test on sensitive creatures because if it does not affect them, then the pesticides surely will not endanger the lives of humans.

2005-11-03T20:30:00.000-05:00

Dive Bombers Used Against Red Army

No, it is not war against communism. However, it is war against red ants - and our weapons are flies. With their poisonous stings, fire ants can cause major inconveniences, and even death in some rare cases. Their rate of reproduction is also incredible. According to Buck Aultman from the University of Georgia, these red critters have dug mounds all over his 20-acre pasture. Prior to his implementation of dive-bombing phorid flies, he had no means to rid his land of these nasty bugs.

These phorid flies are tiny, about the size of a gnat, and display astonishing behavior; as Brazilian parasite flies, they lay eggs right behind the head of each fire ant – but more importantly, these flies only go after fire ants. The cause for this is unknown, but obviously, no one is complaining.

After the egg is laid, it hatches in two weeks, at which point the larva crawls into the head of the host ant, which consequently falls off. The larva fully reaches adulthood by the time it comes out of the shell of the fire ant’s head, to start this process all over again.

These flies are thus as useful as they are strange; these flies could potentially be the most effective means we have ever had in controlling the uncontrollable population of fire ants.

2005-11-03T19:26:00.000-05:00

Spiders: A "Natural" Insecticide

A recent study conducted by Torrin University shows how spiders can be a strong marketing point for Italian wine-makers who are faced with increased pressure from the “green-minded” public. Without harming the environment, spiders devour insects that feed off grapes and destroy the crop. The study showed that over the course of a growing season, a healthy colony of spiders living in a hectare of vineyard was able to eliminate some 20 million insects, weighing approximately seven kilos. Additionally, a flourishing spider population indicates a healthy, pollution-free environment, as arachnids (spiders) are sensitive to their surroundings and steer well clear of areas that have been doused in chemicals.
According to Professor Guido Badino, “The presence of spiders from the soil up to the top levels of vegetation, as well as their notable predatory capacity, make them an excellent indicator of environmental health.” The study reports that out of the 1400 species of spiders living in Italy, only one is harmful to humans. By examining these results, it is clear that spiders are a favorable insecticide to both wine-makers as well as environmentalists.

2005-10-27T21:41:00.000-05:00

Hungry Bugs

Previous posts have already established that bugs have good potential as a food source. However, it also turns out that bugs are useful when it comes to feeding habits, because some species of bugs help us out just by eating.

Flesh-eating beetles of the species Dermestes Maculatus are employed by museums to clean the flesh out from the skeletons of various animal species. In August of 2004, London’s Natural History Museum acquired 100 of these beetles with plans to breed them until their numbers reach around 1000. These critters provide distinct advantages over the previously employed method of chemical treatment; the chemicals used to dissolve flesh from bones also damage the bone material and alter the chemical structures of the bone to a degree, whereas the beetles only strip the flesh from the bone without changing anything about the bone material at all. Also, the beetles can access the trickier parts of the skeletons to get to the flesh inside, a feat that was previously unachievable by the preparators and their chemicals.

These beetles are also remarkably efficient; BBC News’s “Museum welcomes flesh-eating bugs” article quotes Patrick Campbell of London’s Natural History Museum as saying that, at their expected numbers of 1000, these 1cm-long beetles “will get through about two to four kg of flesh a week.” Considering these beetles’ prodigious appetites, the museum has taken precautions so that these beetles do not break out and start eating at the stuffed animal collections.

Thus it seems that when it comes to eating, insects really can help us out a lot, whether it’s us eating them or them doing the eating for us.

2005-10-27T18:36:00.000-05:00

New Organic Pesticide

Professor Joop van Lenteren, an insect biologist from the Netherlands, found a natural way to eliminate insects. Rather than spraying pesticides from airplanes onto fields of crops, which is not always successful, Lenteren discovered that insects are often effective in killing other bugs. The parasitoid wasp, Encarsia Formosa, is used to prevent insects from wreaking havoc in agriculture all over the world. It is able to kill white flies, which usually attack tomatoes and cucumbers. In the Netherlands, other insects are being bred in greenhouses and they will be used in the future to kill other pests. Using biological control of insects is environment friendly, and is therefore a better alternative to traditionally pesticides. It is also healthier, because there will be no traces of insectides in fruits and vegetables. Lenteren is anxious to educate farmers about this new, healthy, eco-friendly way of stopping pests.

2005-10-27T18:22:00.000-05:00

Hope for Africa

A recent article from Reuters reports that researchers have developed an organic pesticide that can control deadly locust swarms in Africa, reducing the need to use traditional insecticides that harm the environment. Locust, a type of grasshopper, migrates in immense swarms that devour vegetation and crops. Last year, many poor countries in West Africa experienced the worst locust infestation in more than a decade, causing food shortages and major damage to grain crops across a region where many are subsistence farmers.

Spraying juvenile locusts with pheromone, a scent that can be taken from adult locusts, can now prevent these swarms. According to Christian Borgemeister, the director of the International Center of Insect Physiology and Ecology,

“Spraying breaks up the groups, or bands, young locusts live in and exposes them to predators. The insects are highly stressed. They suffer high natural mortality and fall victim to many natural enemies like birds. Pheromone is environmentally friendly and cheap to develop, and its use alongside more expensive insecticides could reduce the amount of those insecticides used in efforts to kill locusts.”

The major element of the pheromone is phenylacetonitrile (PAN). A combination of PAN and a conventional insecticide reduces the concentration of the insecticide more than four fold; clearly showing the environmental benefits of pheromone. The discovery of this organic pesticide is a major breakthrough for Africa and it may save the lives of thousands of people!

2005-10-20T22:21:00.000-05:00

The Most Important Chemist

So it is said that the earthworm is an extraordinary chemist. Without this little helper, farmers and gardeners everywhere would be in big trouble indeed. Living in populations of up to 250 million per acre, the earthworm is vital to the fertility of a region’s soil. First, the earthworm’s anatomy; with a set of five hearts, both male and female organs, and an anus nearly indistinguishable from its mouth, the typical earthworm is not the typical creature. Even with both sexual organs, the earthworm cannot fertilize itself – it must mate with another he-she at which point both partners of this amorous interaction will be fertilized.

One might notice many of these critters coming up during rain. According to the Journey North Teacher's Manual, earthworms use the rain as an opportunity to move aboveground, where they can cover distance faster and thus explore more area. However, one might also catch sight of dried-up earthworms when the sun is up, shortly after a rainstorm. This is because the UV radiation from the sun is lethal to the earthworms, and those who are unlucky enough to be caught out in the sun are toast (literally).

So what does the earthworm do for the soil? It digests it – organic matter and mineral alike – and in its stomach grinds it down into a sticky, rich, and fine material called humus. This is excreted into the soil, where plants can then feed on this nutrient-rich worm poop. Furthermore, by burrowing into the soil, worms also serve to vent the soil – by creating networks of tunnels in the soil, earthworms allow for the drainage of water from the soil, and also for the free travel of air in and out of the soil. Thus, this slimy creature surely is the farmer’s best friend, for without the earthworm, there would be no fertile soil on which agriculture can take place.

2005-10-20T21:49:00.000-05:00

Insects Anyone?

Although it may sound gross to most Americans, eating insects is not uncommon in many cultures throughout the world. An article from National Geographic talks about the custom of feasting on insects. “Bugs remain a traditional food in many cultures across Africa, Asia, and Latin America” In history, groups such as the Ancient Romans and Greeks dined on insects. Not only are insects readily available as nourishment to many communities, but they also have nutritional benefits. Bugs have a high protein content. Unlike a hamburger, which contains 18 percent protein and 18 percent fat, a cooked grasshopper may contain up to 60 percent protein and only 6 percent fat. Insects may also be a more environmentally friendly way of getting protein because they are more efficient in converting biomass to protein than animals such as cattle. Overall, the benefits of eating insects are great, so do not hesitate when grabbing that “Worm Candy” off the shelf.

2005-10-18T18:54:00.000-05:00

Harmless to Humans, Deadly to Plants

A recent Washington Post article discusses how agriculture officials plan to quarantine fruits and vegetable for up to 80 square miles outside the San Jose area because of the discovery of two Mediterranean fruit flies. These insects, commonly called Medflies, pose no threat to humans, but can ruin crops.

“Medflies can destroy more than 260 types of plants by hatching their larvae inside. If an infestation spun out of control, it could cost California $1.3 billion to $1.8 billion. We’ve never had an uncontrolled infestation, but any infestation is a major event,” said Steve Lyle, a spokesman for the Department of Food and Agriculture.

The Medflies were discovered last week in a lemon tree and an apple tree in a residential area. Officials say that the quarantine will begin in a few days, and no fruits or vegetables will be able to leave the area. It is interesting to note how two tiny insects can have such a large impact on the entire region, and could potentially cause up to $1.8 billion of damage. Officials have already released 1.25 million sterile flies in the 10-square mile area of San Jose. These flies are meant to mate with the Medflies, and prevent them from reproducing.

Medflies have caused quarantines before, however most have them have been in southern California. Hopefully, officials will take care of the situation before any major damage is caused. With the current financial situation of the government, it would be tragic for taxpayers to spend an additional $2 billion to repair the damage caused by two small insects.

2005-10-13T21:33:00.000-05:00

More than Pests

Ants, termites, caterpillars, grubs, and grasshoppers. Even the mention of some of these insects is enough to induce the gag reflex in some individuals, and yet, these insects might just be what our diets need. With plenty of potassium, calcium, and magnesium – minerals that we frequently neglect to intake sufficient amounts of but are vital to our bodies – bugs are truly the “all-natural and clinically proven™” diet supplements.

Even better, insects also boast large amounts of protein and carbohydrates, amounts larger than those found in beef or fish on a weight-for-weight basis. While many a brainwashed member of today’s pop culture may shy away from the mere mention of carbohydrates, fearing the number at the top of the bathroom scale, there are those who are willing, and even desperate, to eat whatever they can get – the hungry masses in Africa. Do not mind them, however; according to Julieta Ramos-Elorduy, a researcher quoted in Alison Fromme’s article Edible Insects, those of us across the world with enough to fill our stomachs spend billions of dollars every year on chemically protecting crops of less nutritional value than that of the insects killed to maintain them. The real irony is found, however, in that hunger relief aid efforts are buying these crops that cost so many insect lives to grow, from the very people who are depriving the hungry of a better and more abundant food source.

Ushering in an age of Big Macs and Oreos, we get more than our share of general unhealthiness in our diets – this should be reason enough to include these critters on our plates. But more importantly, for those of us humans who do not even have the option of clogging their arteries with artificial fat, for those of us who are starving – insects just might be the godsend that was always there.

2005-10-13T20:14:00.000-05:00

If You've Got It, Flaunt It

Pyrrolizidine Alkaloids (MNO), which are chemicals that plants produce to ward of insects, have a large effect on the biology of salt marsh moths. They stimulate the growth and development of the coremata organ in male moths and they also affect the male’s mating habits. The behavior in the courting rituals is drastically changed by the presence of these chemicals within the moth’s system. In a study called, If you've got it, flaunt it: Ingested alkaloids affect corematal display behavior in the salt marsh moth, Alex T. Jordan, Tappey H. Jones, and William E. Conner discuss Pyrrolizidine Alkaloids and their physical and behavioral effects on salt marsh moths. They discuss the changes in the moths courting rituals, which they studied under laboratory conditions. Males fed a diet containing MNO display their coremata, while males fed the same diet without the alkaloid never display. The study uses very technical terminology, but will be fascinating to anyone with a background in chemistry and an interest in insects.

2005-10-13T10:03:00.000-05:00

The Wasp Moth: Practicing Safe Sex

The scarlet-bodied wasp moth, native to Florida, has the unique ability of releasing a cloud-like toxin to protect itself during mating. According to the article, “A Gift of Poison: moths and safe sex”, just before mating, the male moth releases the pyrrolizidine alkaloid toxin like a cloud of miniature confetti that sticks to the female. The female moth is immune to the toxin, and it protects the moth while she is mating and laying her eggs. The entire process lasts approximately nine hours.

In order to be able to release these poisonous pyrrolizidine alkaloid toxins, the male wasp moths have to go through a long process. As caterpillars, the male moth feeds off a non-toxic plant, climbing hempweed. After the caterpillar becomes a moth and ready to mate, it changes its eating habits. The moth starts to then go to the poisonous dogfennel plant. In open pastures, dogfennel is easy to spot because cows eat the grass, but leave the dogfennel untouched. The moth “lands on the plant, regurgitates on the plant to dissolve the alkaloids and then reimbibes the toxin-rich liquid,” says William Conner, a professor at Wake Forest University. The male moth stores the pyrrolizidine alkaloid toxin in a special pouch and releases it during mating.

In an experiment conducted by William Conner, the moths were placed in the web of a golden orb-weaving spider. Instead of eating the moth, the spider cut the web to release the moth. The scarlet-bodied wasp moth is the only known insect to transfer chemical defense in this manner, but the link between chemical defenses and sex will definitely be studied in the years to come.

2005-10-06T19:52:00.000-05:00

Pyrrolizidine Alkaloids: Boon for Moth and Bane for Man

Pyrrolizidine alkaloids are bitter substances that are found in a wide range of plants. They have no function in the actual activities of the plant, but serve to protect against animals that might eat it, because of the alkaloids’ bitter taste. Chemically, pyrrolizidine alkaloids contain nuclei each consisting of a linked pair of pyrrole rings, which can be represented as pentagons comprised of four carbon atoms and one nitrogen atom.
These alkaloids are highly toxic. They are known to be acutely hepatotoxic, toxic to the liver, in both humans and animals. They are also confirmed as animal carcinogens – their roles in cancer in humans are as of yet unconfirmed. While animal poisoning by these alkaloids is quite common owing to the fact that these alkaloids exist in many grazing plants, human poisoning is rare; usually, it happens because people who have no knowledge of these alkaloids use homemade herbal remedies or preparations that contain such alkaloids. Humans can also be poisoned by consuming contaminated food products such as cereal into which pyrrolizidine alkaloids have found their way, or meat (or by-products thereof) of animals contaminated with these alkaloids.
According to Safety Issues Affecting Herbs: Pyrrolizidine Alkaloids, an article by Dr. Subhuti Dharmananda of the Institute for Traditional Medicine, the pyrrolizidine alkaloids themselves are not really toxic – the liver breaks them down into metabolites that are then highly toxic to their surrounding environment. The metabolites disrupt the liver cells and stop them from functioning properly, and cirrhosis may occur if the liver is exposed to the metabolites long term. Veno-occlusive liver disease almost always results from exposure to pyrrolizidine alkaloids; the blood vessels from the liver to the heart become blocked.
So, while these fascinating little molecules might save some moths from being eaten by spiders, they have a profoundly negative effect on us, and as such we should do our best to avoid them.

2005-10-06T19:15:00.000-05:00

Cocaine as an Insecticide

Though cocaine is extremely harmful and dangerous to humans, it is a very effective botanical (or natural) pesticide. In the Fly in the Ointment, Dr. Joe Schwarcz discusses how insects are the most “notorious of plant predators,” and that coca plants synthesize cocaine as an insecticide. Cocaine is generally found on the leaves of the plant, however it was not until recently that the actual purpose of the cocaine was discovered. Schwarcz refers to an experiment in which a cocaine solution was placed on tomato plants and then placed moth caterpillars on those leaves. “The insects reared up, began to shake, and turned away from the cocaine, apparently showing greater intelligence than some humans.” In a study done by James A. Nathanson from Massachusetts General Hospital, their experiments showed that “insect larvae exposed to cocaine-sprayed leaves displayed marked behavioral abnormalities, including rearing, tremors and walk-off activities.” They assert that cocaine’s toxicity is because of its “ability to block reuptake of octopamine, a key insect neurotransmitter and hormone that regulates movement, behavior and metabolism.” It is because of this hormone, octopamine, that cocaine is such an effective insecticide.

2005-10-06T16:37:00.000-05:00

Nicotine: The Smoker's Drug is also a Pesticide?

In Dr. Joe Schwarcz's essay, "Munching on a Chemist", he brings up nicotine as an example of a natural pesticide that plants create to ward off insects and avoid being eaten. This is probably a surprising fact to smokers, who are inhaling this very substance into their lungs everytime they smoke a cigarette. In fact, declaring that "one single drop of that stuff in your blood stream would kill you," as Florence Cardinal does in her article about "Nicotine: The Smoker's Drug", would probably discourage a lot of smokers even more than pictures of blackend lungs or fine print warnings about the danger of smoking on the bottom of cigarette ads. In her article Cardinal discusses how nicotine is used as a insecticide and it's toxicity to mammals. After reading this article one should surely think twice about ever letting a cigarette near one's mouth.