Ladybugs! Attack on the Orange Powdery Stuff?

This summer I worked in the greenhouses on Rice University’s campus tending to tallow trees, clover, and other plants. Several different organisms invaded the plants, including spiders and snails. The worst of these pests however, were the spider mites.

While watering the plants, I began to notice that many of the clover and tallow tree leaves were fading to a pale yellow, and everywhere I saw yellow leaves there was always what looked like an orange powdery substance on the plant. In taking a closer look I realized that the “powder” was made up of thousands of tiny orange arthropods, the spider mites.

Photo cred: Ariel Nixon
Colony of Spider Mites on Clover
Photo cred: Ariel Nixon

Spider Mites are not actually spiders but they are mites in the order Acari and family Tetranychidae.  They get the name “spider” from their ability to spin silk webs around the leaves of various plants. There are over 1000 species of spider mites alone, and I think the species I saw was Tetranychus urticae, the red spider mite. Although spider mites do not live longer than a couple of days, their numbers can grow exponentially. One female spider mite can lay 20 eggs a day, and each egg matures into an adult in less than a week. This leads to huge colonies like the one seen in the photo of the clover. The mites eat individual cells on the leaves lowering a plant’s ability to photosynthesize and causing the plant to loose coloration. Pesticides and other treatments are usually ineffective against spider mites because of their fast generation times. Each new generation of these insects develops in 5 to 7 days, which means that a single population of spider mites can build resistance to such chemicals in a matter of weeks.

Photo cred: wikipedia.org

My professor and lab manager Dr. Siemann suggested that we order ladybugs to rid the greenhouse of these pests. Yes, it is possible to order live ladybugs from the Internet! Ladybugs also known as Ladybirds and Ladybeetles are in the beetle order Coleoptera and family Coccinellidae. These insects are amazing predators against pests such as aphids and mites that attack crops and other plants. They are actually considered sacred in many areas of the world because of the “good luck” they bring to farmers. There are over 6000 species of ladybugs; the most common species of ladybug found in the U.S. and the one we used in the greenhouses is Coccinella septempunctata. This ladybug has red elytra with black spots. Other species of ladybugs are black, orange, yellow, and even blue. Ladybugs possess the ability to secrete smelly and disgusting substances when in danger. In what is called aposematic coloration, their colorful elytra ward off predators by letting them know they taste bad! Like all beetles, ladybugs have powerful mandibles, which are sharp teeth-like structures that move horizontally. These allow them to munch on several tiny organisms.

Once our package of 4000 ladybugs arrived from California we went through the process of distributing them on the leaves of each plant. This took some time, as ladybugs are quick to fly! Surprisingly, over the next week the number of spider mites decreased substantially as well as the number of other pests. The ladybugs must have had a huge appetite from their trip to Texas!

Watch this video of ladybugs eating aphids!

Luck Be a “Ladybug”

One day, I was just chillin’ in Duncan commons, chatting with a friend and sort of studying at the same time when out of nowhere an insect commonly known as a “ladybug” came and landed on my arm. Of course, my instant reaction was “Insect Blog Moment!! Must. Get. Camera.” So of course I scrambled to get my phone out of my bag, but I was certain to not scare the lady bug off of my arm. Why? Well, there’s the obvious reason of needing it to take a picture, but then there was also a secondary reason, a more instinctual reason, something that has become ingrained into me over the course of my life: Having a ladybug land on you is good luck, but scaring it away will bring you bad luck. Being the superstitious person that I am, my subconscious would follow this rule just as religiously as knocking on wood and throwing salt over my shoulder. However, after thinking about it, I realized that this one is a bit more strange. Generally, people try to avoid insects, or at least avoid having them land on their arms. Even your body reflexively has you swat at things that land on your skin and move the hairs ever so slightly. There generally are only a few exceptions to this, one being butterflies and the other, ladybugs.

But why? Butterflies have the advantage of being beautiful as well as having a fragile and harmless appearance. However, I wasn’t buying the idea that simply the red coloration and polka dot pattern was enough to make ladybugs lucky, so I did some research.

The first thing I found was that, as you may have guessed, ladybugs are not actually bugs. Instead, they belong to the order Coleoptera (aka beetles) and more specifically, the family Coccinellidae. It’s estimated that in this family there are about 6,000 species with a diverse range of colorations and patterns. I also found that in the UK, they are commonly known as “ladybirds” and “ladycows,” which both confused me and made me proud that even if it is still incorrect, at least the American common name is within the right phylum.
Source:http://entnemdept.ufl.edu/creatures/beneficial/lady_beetles.htm

But still, even all of this information does not answer my question of why Coccinellidae are considered lucky. To my surprise, I found the reason for their luck as well as the origin of their common name in the same article. As we have discussed a bit in class, one of the main niches that Coccinellidae fill is as a predator for aphids. In the act of preying on aphids and other insects, they aid in crop protection. This act has been appreciated by farmers for centuries and it is speculated that it is exactly this role that has earned the Coccinellidae the universal reputation for being lucky. And, in fact, unlike other superstitions, this one may hold some validity since the scaring away or killing of these insects might actually bring you “bad luck” as you watch the aphid population spiral out of control and destroy your crops. Now, the name “lady bug” stems from a related superstition started by Catholics that states that it was the Virgin Mary (also known as Our Lady) who sent these insects to help protect the crops, resulting in their iconic name as well as providing the inspiration for yet another depressing British nursery rhyme.

There has actually been a bit of research done into using Coccinellidae as biological controls for pests as was seen in the presentation on Citrus Greening. However, there is still much research to be done to be able to effectively use and quantify the benefits of using these insects for that purpose. Specifically, more research into the effects of pesticides, proper conservation techniques, and effective sampling techniques is crucial for gaining a better understanding of the effects of the use of Coccinellidae as a biological control. To learn more about this, read this paper from the Annual Review of Entomology.

And after explaining the origins and potential validity of this superstition, I have to tell you that to get a good enough picture I actually had to take this little member of the Coccinellidae family off of my arm and put it onto a plant. Although it pained me to do so, I reasoned that since I was actually bringing it into a habitat that it is more likely to enjoy, it should spare me from any bad luck curse…hopefully.

Earwig Surprise

It was an ordinary Tuesday afternoon, and I was doing my homework on the orange couches in the McMurtry commons. When dinnertime came around I decided to pack my things and then head over to cheer practice, but something else decided to make moves as well. On the bright orange cushions there was a curious insect, Euborellia annulipes (Lucas) also known as the ring-legged earwig crawling out of the crevices. While my best friend called me gross and whined “eew” a bunch of times, I was eagerly trying to get a clear photo of the earwig using my iphone.

Photo by Alyssa Thomas

So why was there an earwig inside the commons and how did it get there? Well this species has been identified in the United States since 1902. They are nocturnal and are commonly found outside beneath stones or in hidden areas; contrary to the belief that they crawl into human ears to lay their eggs. They prefer temperate or tropical environments, which means they tend to migrate indoors when it is too hot and dry outside. This may be the reason why I found one hidden in the air-conditioned common area. I figured that he was possibly waking up to eat some food like the rest of McMurtry students, which is why I did not see him come out until it was about 6:30p.m.

However, earwigs prefer to eat other insects dead or alive, which may be equivalent to the servery food on certain occasions. They are also known to feed on plants. These harmless pests do not quite bite, but they do have enlarged cerci used as forceps to protect them from other insects and mating.

Photo by Professor Miller

Their cerci is important in determining the sex. I was referring to the individual that I found as “he” because his cerci were more curved and spread out, which is indicative of the male. The female receives sperm from the male after interacting using their cerci. She holds the sperm until she is ready for them to be fertilized. The nymphs are born wingless and undergo simple metamorphosis.

Female earwigs are known to show maternal care, which is uncommon in insects. An article here explains how there was research done a few years ago about how mother earwigs favor their most-fit children. It is pretty selfish and not something done with most human relationships, but they are simply allocating their resources properly. It was found that the healthy babies emit a chemical signal that attracts the mother. Once she has signaled out her favorite kids, she simply regurgitates her food to nurse them.

So now you know why your older brother always got the new stuff while you had to settle for the hand-me-downs, your mom just wanted to invest all her time and resources to raise him perfectly since he was her first child. Anyways, don’t cover your ears from earwigs, but get to know them!

 

 

 

 

 

 

Beware the Bees!

About ten years ago, my father had a near death experience (NDE). It wasn’t caused by a car accident, heart attack, or any other sort of traumatic experience. His NDE was the result of a single bee sting; no different from the ones we’ve all had countless times. He collapsed to the ground off his bike and was subsequently rushed to a nearby hospital. Anaphylaxis set in, and his throat nearly closed shut. At first, the nurses disregarded his condition. However, once they measured his blood pressure, they sprung into action, eventually restoring his health.

Of course, anyone who has a wasp or bee allergy has heard these types of horror stories and has taken necessary precautions to avoid these circumstances. However, in my father’s case, he had no idea that he was allergic to bees. He had been stung many times before (as a consequence of working outdoors his entire adult life), and never experienced such a severe reaction. In fact, nearly half of all people who die from bee sting anaphylaxis did not know that they were allergic to bee stings (http://www.webmd.com/allergies/understanding-bee-sting-allergies-basics). So, how do you just become allergic to bees? What should you do if you suddenly find yourself reacting severely to a bee sting? And who should be worried about becoming allergic to bees?

Put bluntly, anyone can become allergic to anything, anytime. Even my father, about 40 years old at the time, suddenly became allergic to bee stings, seemingly over night. The primary suspect is a chemical called melittin, which stimulates nerve endings of nerve receptors in the skin. Injection of melittin into a normal person’s body is followed by a sharp pain that lasts a few minutes, which then gives way to a dull ache. In other words, you’ll heal before you’re married. However, if the melittin circulates your blood stream and finds antibodies associated with cells on your vital organs, these cells will begin to release massive amounts of histamines, and soon your blood pressure drops and fluid builds in your lungs  (http://www.wvu.edu/~agexten/wildlife/bees.htm). These symptoms, collectively called anaphylaxis, can be life-threatening if not treated.

Luckily, there’s a relatively easy solution to anaphylaxis. Injection of epinephrine (adrenaline) will usually reverse any ill-effects of a bee sting within seconds. Epinephrine works by acting on receptors on blood vessels to increase blood pressure.

Truly a life saving device!

Image courtesy of http://www.myallergycare.com/

As far as genetics are considered, people whose parents are allergic to bees are not necessarily allergic to them as well. It is true, however, that if your parents are allergic to bees, there is a great risk that you are allergic to something as well; but not necessarily bees (http://abcnews.go.com/Health/AllergiesOther/story?id=4522443). It’s important to note that allergies arise from a combination of genetics (from your parents) and a certain exposure to something in the environment.

Every so often, I receive a group text from my mother to all her children. One day last week, we all got this lovely mugshot of my father with the caption “SEND HELP!:

Reppin Rice all the way up in Ohio!

At least he can have a sense of humor about it.

Satiate Your Hunger With This!

You may have heard that, in a not too distant future, there will be a point where meat becomes so scarce that you and I may have to find alternative source of animal protein, say, from BUGS. Yes, I totally understand that you would rather become a vegetarian than see bugs on your dish.

 

(Photo Credit From mad4scinence.com)

But believe it or not, it turns out that we CAN and indeed we have EATEN them for many years!

According to the UN’s Food and Agriculture Organization, insects form part of diets of at least 2 billion people around the world. Surprisingly, there are more than ONE THOUSAND NINE HUNDRED species people eat as delicious cuisine (Yen at Al). Although insect-eating is not widespread in the western world, such as in Europe, North America and Australia, insects (including other species of invertebrates) are regularly eaten today in Africa, Asia, Central America and South America. Moreover, eating insects can be very environment-friendly and a potential solution to the global food shortages. Add to that, farming insects produces less greenhouse gases, and therefore, is a more efficient way to produce sustainable protein. (http://www.fao.org/docrep/018/i3253e/i3253e00.htm)

Still for some people, the idea of tossing these creeping, crawling creatures into your mouth may sound too daring, even though insects can be quite tasty and nutritious. So I have decided to embark on a journey of eating insects, simply to convince you that eating them is a fun and practical experience. So let me draw your attention to one of very common bugs you see around. Crickets!

Crickets belong to the family of Gyllidae under Orthoptera order. Four crickets contain as much as calcium as a cup of milk. If you eat 100 grams of crickets, you are consuming 121 calories (ONLY 49.5 calories from FAT) and as much as 13 grams of protein and 76 milligrams of iron. (http://www.menshealth.co.uk/food-nutrition/healthy-eating/the-nutritional-value-of-insects) (http://www.menshealth.co.uk/food-nutrition/healthy-eating/the-nutritional-value-of-insects)

Conveniently, I was able to find processed crickets in a vending machine at the Natural Science Museum in Houston during my class trip.

As I rushed back home to savor the taste and flavor of the bug, I carefully poured my cheese-seasoned crickets on my dinner table. With a single deep, solemn breath I put one of these tiny creatures into my mouth.

At first, the smell of cheese-and-bacon seasoning was a bit strong, which made it difficult for me to focus more on the taste of bug, but as I kept chewing it, a nutty flavor along with crunchiness that resembled the sensation of chewing dried shrimps started to fill my mouth. Although I could definitely feel one of the cricket’s legs and a part of his wing stuck in my teeth, eating crickets overall was a very pleasing experience.

(Photos taken by Hansol Park)

Knowing that commercialized foods can sometimes deter us from appreciating the true taste of the nutrients, I have decided to prepare a real dish made out of bugs for my upcoming blog posting. There will be lots of chopping, steaming, and seasoning involved. Please look forward to my next posting!

 

🙂

 

Further Citation;

Yen, Alan. At all. ‘The Role of Edible Insects in Human Recreation and Tourism.” Ed. Raynald Harvey Emilin. Cambridge University Press. 2013. Online Fondren Library.

Deutsch, Jonathan. ‘They eat That?: A Cultural Encyclopedia of Weird and Exotic Food from Aroud the World.’  Google Ebook 2012. Online Fondren Library.

 

Terror from Above…WASPS

There are very few encounters one may have with an insect that elicits as much fear, panic, and an absolute sensation of vulnerability, as having an angry, grotesque, and much-too-large-for-anyone’s-good wasp come flying out of nowhere straight toward your face when and where you least expect it. Actually, there is something more frightening: two f****** wasps launching an utterly unjustified assault on your face.

I recently had the most unholy of fortunes to experience such an attack. Returning one day to my dorm room – a sanctuary of tranquillity and refuge after a long day of classes – I opened the door and was greeted by a most unnerving hum. I began to investigate the source of the noise. Upon completing an inspection (and finding nothing) under my bed, I raised myself off the floor and turned around towards the window. I abruptly located the source of the sound. Unfortunately, the source – in fact sources – were hurtling themselves into my face. This is the part where everything went into slow-motion. I discerned the hellish features of two wasps, their thin waists followed by oddly enlarged stingers, and my impending doom. I dropped to the floor in an attempt to dodge the flying fiends, and managed to just miss them by a hair’s width. I glanced around, spotted and grabbed a towel, and righted myself, as the wasps swung around for a second assault.

The thin waists (or petioles) and augmented abdomens (on which ridiculously large stingers are attached to) are identifying trademarks of the wasps in the family Sphecidae. About one-and-a-half inch long, the wasps that randomly decided to terrorise me (and my roommates) were of the species Sceliphron caementarium, commonly known as the black and yellow mud dauber. Called mud daubers due to their ability to build nests with mud, these wasps are solitary in nature. The black and yellow mud daubers form nests by gathering mud into spheres, then shaping them into cylinders, which are then aligned together and covered entirely in more mud. The finished nest in around the size of a fist, and are found (rather inconveniently for us humans) on man-made structures such as under bridges, doorways, and windows.

Despite the fact that these horrifying creatures possess characteristics and appearances akin to some sort of ungodly love-child of a scorpion and killer bee, these mud daubers and most wasps in general are not considered as pests, due to the fact that they are rarely aggressive and seldom attack humans unless thoroughly provoked. Furthermore, unlike some other Hymenopteras that work in groups (ie the yellowjacket, which, when killed, releases a chemical that draws nearby yellowjackets to attack), the solitary nature of these mud daubers mean that you will probably never have to deal with a swarm of them (heaven forbid). In fact, wasps may be considered beneficial, as they can get rid of other arthropods that we (humans) likely find more disagreeable than wasps. Such as spiders. For example, one wasp that very spectacu-

The Terrifying S. caementarium (Actual Size)

-larly kills its prey is the tarantula hawk. Upon locating a tarantula, the wasp will sting it to paralyse it permanently. The wasp then drags the spider back to its nest, where it lays an egg within the spider and seals the nest. After hatching, the larva begins slowly feeding on the insides of the tarantula, and finally rips open the spider’s abdomen, a la the eponymous alien from Alien. Similarly, the black and yellow mud dauber paralyses a spider and places it in its nest, prior to laying an egg in the nest and sealing it. The larva then – you guessed it – feeds on the helpless spider while the larva grows. Mother Nature can be cruel.

Back in the room, I swung at the two wasps numerous times to no avail. The situation only became more dire when the two wasps, which had previously been flying around together, decided to split up and launch a two-pronged assail on me. I fled the room and closed the door before the wasps could follow. This was insane and ludicrous; I was laying siege to two wasps that I had seriously aggravated without realising it. After a ten minute wait, I cautiously opened the door to find the wasps stationary on the window. I proceeded to grab my shoe and smashed both wasps repeatedly not once or twice, but thrice. The wasps landed on the windowsill, still alive and writhing. After bashing them two or three or seven times more, they were finally gone. Triumphant, I scooped the remains and tossed them out the window. I had once again foiled an assassination attempt (not really) from nature!

SHAKE THAT BEETLE BOOTY!

Photo Credit: Charlene Thomas

During the summer, I was fortunate enough to take the EBIO 319 class.  It was a two-week course that took place in the breath-taking and exotic Belize.

While strolling through the magnificent Chiquibul rainforest, we saw longhorn beetles mating! We probably spent a good thirty minutes observing this bizarre sexual encounter!

Before I start, let’s learn more about the longhorn beetles!!

The scientific name for longhorn beetles is Cerambycidae.  Cerambycidae is a rather large family of beetles that consists of thousands of species.  They are worldwide and their range is from sea level up to 4,200 m elevations.  As larvae they feed on decaying wood while adults feed on flowers.  Longhorn beetles tend to live for 1 to 3 years.

The beetles we saw in the rainforest were spectacular.  Black with bright yellow strips running down their back, their exceptionally long antennae… UGH, what a beauty! The antennae were also two different colors.  The base was black and it gradually turned into an orange/yellow color.

The first thing that caught my attention was the fact that the female longhorn beetle was much larger than the male longhorn beetle.  This seems odd just because we are so used to sexual dimorphism in the other direction (males being larger than females).  I’m not sure why this is the case, but it would be something worth looking into.

Now to the copulation!

Disclaimer: This is all based on my observations and inferences; I cannot definitively say this is how this particular species of Cerambycidae mate.

First, the male beetle latches onto the female. Once he is secured, she would lead both of them to the “ideal spot” for her to lay her eggs.  Once she found the spot, the copulation would begin.  While they were mating, we noticed that the female longhorn would create a horizontal slit with her mandibles.  Once they finished, they would reorient themselves so that the horizontal slit would be located where her ovipositor was. During this entire process, the male still has a strong grip on the female. Once her ovipositor was inside the horizontal slit, she would begin shaking.  We made the assumption that this was when the female deposited her eggs into the tree trunk.  They would repeat this process numerous times.  Unfortunately, we couldn’t continue creeping on the critters because it was getting dark outside so we returned to the research station.

If you want to learn more about these awesome Longhorn beetles check out awesome websites below!

http://bugguide.net/node/view/171
http://eol.org/pages/357/details
http://www.fzi.uni-freiburg.de/InsectPestKey-long%20version/cerambyc.htm

Click on video to watch the beetles mating!

So the Beast Gets the Beauty After All

Photo of a Rhinoceros beetle taken (by me) at the Houston Natural Science Museum

Coming to a butterfly garden, I didn’t expect this.

In a place where colorful, graceful, and beautiful creatures flutter freely, who knew this beast could be living right next door? As I got to go “behind the scenes” of the natural science museum in Houston, Texas, I saw for the first time an insect that just did not look like it could be real. Perhaps in a sci-fi horror film where large, disgusting insects take over the cities, or maybe in prehistoric times when were centipedes as large as automobiles, but certainly not now, in 2013, in a back room of a science museum.

It was called the Japanese rhinoceros beetle, and it was the most terrifying insect I had ever seen in real life. It was huge; its width was the entire size of a human palm. It was jet black, with two large horns that looked like pincers sticking out of its head. You can imagine my surprise when the woman who had brought me to the room confidently stuck her hand into its cage and scooped it right up.

No, those weren’t pincers. It was not aggressive, nor evil, and did not attack anybody in the room. Instead it calmly sat on her palm, letting everyone in the room caress its black body.

What was the point of those deadly looking horns if not used for clamping onto threats or meals? As it turns out, the horns themselves are worn by males mainly just for show. Here, we see a wonderful example of sexual selection.

In this article from Discover Magazine, Ed Yong states that “the growth of the horns is intimately tied into molecules that reflect how well-nourished the beetles are”, and thus “females can rely on the size of the horns to judge a potential partner’s health”. So, the bigger the horn, the more potential for mating! And, as we know, there is nothing an insect likes more than to mate (along with eating).

So just how large can these horns grow? According to Stephanie Pappas, some males grow horns up to two-thirds their body size! That is ridiculously massive. To put that in perspective, that would be like the average 5’10” human male having horns on his head that extended nearly 4 feet!

It would seem as though with such huge horns, perhaps the mobility or flight of the beetle may be at a disadvantage. (Wouldn’t you expect a man with 4 foot horns sticking out of his head to be maybe just a little bit impaired?) This, however, does not seem to be the case with the rhinoceros beetle. In this scientific journal, it is explained how testing was done on rhinoceros beetles to come to this conclusion. McCollough chose rhinoceros beetles who had horns about two-thirds their body length. After euthanizing them, she weighed them with and without their horns. She also determined the center of mass of the beetles with and without their horns, as well as how the horns affected drag on the beetles’ bodies.

The findings were a surprise! The horns were very dry and hollow, making up only .5%-2.5% of the beetles’ body weight. Thus, they hardly changed the beetles’ center of mass. The beetles fly slowly with their bodies almost vertical; in such a position, the horns do not affect the flying at all.

Photo of a Rhinoceros Beetle taken by Devon Troutman

So beetles with the biggest horns get the females AND don’t have to pay for it? Sounds like the best of both worlds to me. It seems as though in the insect world, sometimes the beast does, in fact, win over the beauty.

To see more picture of the amazing rhinoceros beetle, you can go here.

Welcome Back to an Often Overlooked World

The hunt was on. It started on a sunny September morning in room 124 of the Math/Science building. The prey: any insect. The method: catch, kill, pin. The prize: an outstanding insect collection comprised of representatives from 10 orders. To accomplish this required a natural ability and also a keen, discerning eye.

At first I felt ridiculous, peering into bushes, along stems, and under leaves with the intensity of a seven-year-old on a scavenger hunt. However, in a short time I relaxed and began to balance my intense hunting with everyday life. As more time passed, it became second nature for my eyes to pick up on a subtle twitch or flash of color on a fence, a leaf, or a stalk, which indicated the presence of my prey. Then it was only a simple matter of excusing myself from any given conversation, swiftly retrieving my kill jar (a glass mason jar containing ethyl acetate), carefully positioning myself with respect to my target, and smoothly bringing the jar and lid in a dual motion together over the unlucky insect. Then I returned to the conversation, which more often than not had come to a halt because my peers where standing completely still, incredulity etched on their faces.

The questions they asked were varied, but the most common was “How did you see that?!” In truth, I saw the movement because I was subconsciously looking for it. Advanced Biology’s insect collection assignment added another dimension to my view of the world by teaching me to see what is always present around us but often overlooked. 

~

That was four years ago during the fall of my senior year in high school. Following the insect collection assignment, I was adept at noticing the subtleties of the insects all around us. However, no longer tasked with the necessity to catch and kill these creatures, I found myself slipping back into society’s norm of obliviousness to nearly any and all things that don’t demand our attention. Thinking back to that time, there wasn’t a day where I didn’t see insects – whether I was intentionally looking for them or not. During the four-year hiatus, I rejoined the majority of society, only acknowledging an insect’s presence when it drew blood, smacked us in the face, or awed us with its beauty. (Now this isn’t entirely true – the fieldwork I’ve done in New Mexico reawakened my eye for spotting insects.) Signing up for Insect Bio and the lab course welcomed me back into this often-overlooked world.

So, what do you see in this picture? If you said, “Nothing but the Will Rice Quad.” you would be like the majority of my peers. What the keen eye (and a better camera) can pick out are several swarms of gnats moving in vacillating masses above the grass. Depending on the time of day, you can also see five to seven insects from the order Odonata in a feeding frenzy. Interestingly, dragonflies fall into two types of hunters: “hawkers” and “perchers” (Olberg et al. 2005). The hawkers continuously fly during the day to forage while the perchers land on the ground or vegetation and take off when prey flies by. Regardless of their hunting style, their method of prey capture is the same. Dragonflies approach their flying prey from below and rise up at the last moment to ensnare them in their extended legs (Olberg et al. 2005). From my observations, the quad’s gnat feeding dragonflies are hawkers.

I now make the conscious decision to walk around the quad, whereas some of my less observant peers insist on cutting across it oftentimes swatting gnats out of their faces while spitting out small, mangled bodies.

Olberg, R. M., Worthington, A. H., Fox, J. L., Bessette, C. E., & Loosemore, M. P. (2005). Prey size selection and distance estimation in foraging adult dragonflies. Journal of Comparative Physiology A191(9), 791-797.

 

 

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