Wow, what a summer!!! I have some exciting news to report…I didn’t get bit by ONE mosquito all summer!!! Just kidding, my project is a little more exciting than that! I did it! I successfully put together and executed a project that I was a little iffy about back in May, and developed a new-found love for mosquitoes [fake news, don’t tell them I said that!]. I now like to be referred to as the mosquito whisperer, so if you see me on the streets, I will not respond to any other name.
But now, let’s get to the good stuff! Last time you heard from me, I was getting ready to start recording male/female pairs of mosquitoes. Now, I have about 7,000 audio and video recordings of these interactions, and I couldn’t be happier with the data I collected! The goal for this stage of my research was to observe whether or not mosquitoes actually communicate with one another to signal their interest in mating, or basically flirt. Below are the visual results of this from the previous study.
For my own recordings, I was able to detect the presence of these interactions by importing my audio files into a computer program called Audacity. Within this program, I could convert the sound file into a spectrogram that was able to clearly show me the frequencies produced by the mosquitoes in the recording. What the heck am I talking about, you ask?? Below is one example of a recording spectrogram that revealed a converging interaction!
But before I get into explaining the scary pink and blue stuff above, let’s talk about how I got these recordings in the first place- that’s the fun part (minus the 500 times mosquitoes got loose in the lab and attacked all of my friends…losers)! About midway through the summer, I changed some of my methods to make my procedure a little easier and reduce the number of casualties caused from pinning my little friends onto insect pins…yeah, they were not happy with me when they woke up from their nap to find themselves stuck to a wire…but, you got to do what you got to do for science!!!!! At the beginning of the summer, I was using insect wax (a yummy combination of beeswax and rosin) to fix these guys to their new home, but it turned out that the wax wasn’t strong enough to keep the mosquitoes in place when they woke up, and more often than not, they flew right off of the pin and straight for my face. So, I decided to try pinning them with a tiny amount of superglue, and it worked magically! The trick was to touch the super glued side of the pin to the mosquito’s thorax (pictured below) instead of their abdomen, which is where I was attempting to pin them when I was using the insect wax. When I tried to pin their abdomen with superglue, sometimes their wings would get stuck to the pin, making it a little bit difficult to get a good recording when their wings couldn’t move… Instead, their thorax provided a perfect amount of surface area for the pin without interfering with their antennae or wings at all.
Once I adapted this method, pinning them was a breeze! I kid you not, I could probably pin 20 mosquitoes within 30 seconds. You’re impressed, I know, I was too…Below are a few examples of my mad skills.
Don’t they look so comfortable and happy!? Next, I set up my recording stands, which were actually 3D printed ‘micro-manipulators’ designed by Backyard Brains! My company is so cool… These stands were used to fix the mosquitoes, with the help of some silly putty, for the duration of the experiment. They were perfect.
Now I was ready to record!! Below is a beautiful video of one of my experiments (I’m a little proud of myself, can you tell?) Make sure you turn on your sound!!
How creepy is that??? These noises will be burned into my brain for the rest of my life! But isn’t it also super cool? You can definitely hear the difference in sound between the two sexes, but can you hear when they begin converging?? Listen again.
If you’re thinking that it happens roughly 20 seconds into the video, lasting about 15, you’re right!! But just to be safe and make sure that the noises we were hearing were indeed interactions, I imported both files into MATLAB for a closer look
Here you can see the two different frequencies of the female and male (though there is a bit of noise blocking the females’ fundamental frequency). The key to detecting an interaction is to look at the higher frequencies, up in the harmonics, around 1200 Hz because this is where convergence will normally occur. And lucky for us, it did! On camera! I was so excited I just about packed up and called it a day, but I really wanted to see some more interactions, so I pinned 8 million more mosquitoes and got down to business! In the end, I was able to successfully record, both audio and video, 49 male/female pairs, observing interactions in 33 of them! That means, in the small sample size I had, the pairs would communicate a love interest to one another 67% of the time! Gross, get a room!!!!
Nearing the end of my time in Ann Arbor, I finally finished recording, throwing in the towel for my beloved new hobby, and I was ready to start processing my data in the hope of making it a little more ‘Hollywood’ as Greg would say! Little did I know, this process wasn’t as appealing as I first thought, and on multiple occasions I considered playing with some more mosquitoes just to get away from the madness known as MATLAB. Lucky for me, I had a MATLAB expert living with me (Hmmm…maybe that’s why we became best friends since she couldn’t escape me anytime I opened my computer to work!) Christy helped me create the most magical, color coded, satisfying and all around perfect video of not only my little buddies interacting, but also a spectrogram underneath it that played in perfect sync with the original video recording! Brace yourselves…you will never see anything more beautiful in your life…
If you caught yourself replaying it multiple times, don’t fret, as you will catch me playing it periodically throughout the day just for fun. I’m not a nerd. But look, I was successful!!!
We also presented our research at a poster symposium at University of Michigan!
So now is about the time where we wrap up!!! Ah don’t make me leave!!!! But I am so happy with the work I produced this summer and I feel so lucky that I got the chance to be part of this program. Greg Gage, you are the best boss I have ever had (don’t tell that to my dad since he’s the only other boss I’ve had…) and I will be forever thankful for the impact you had on my life as not only a researcher but also an individual. I love you and your family to pieces, especially your little ones that taught me all about Peppa Pig, and are still convinced my name is ‘Dirt’. Wonder where they got that…cough, cough, Christy. I already miss you guys, and I haven’t even left Ann Arbor yet! I’d also like to thank all of the staff at Backyard Brains (Stanislav, Zorica, Will, Zach, Caty, Catherine and John), who made my time here so worthwhile and comfortable- I never felt alone even when my MATLAB would crash, or when my fellow interns would shun me for letting some mosquitoes loose in the lab…
And last but not least, thank you to all of the BYB interns that made this summer one for the books! You will all be a part of my life forever, and I can’t wait to see where our lives take us once we leave each other this evening. You’re all such wonderful people, and I couldn’t have asked for better friends. Love you guys!!
Hi, Haley again!! It’s been an exciting couple of weeks- I’ve become more familiar with mosquitoes than I ever thought I would, learned a TON more Matlab, and even got a few recordings!! My work recently has focused on perfecting the methodology needed to successfully tether a mosquito in a position mimicking their natural free flight position; the tricky thing is to assure it is tethered with its wings free to flap, as my recordings will focus on hearing that irritating noise generated by a mosquito’s wing beat patterns.
After much tedious practice, I finally figured out a way to anesthetize these little guys using ice water and tether them using a very thin insect pin with a tiny amount of insect wax. The goal was to assure that they were suspended in a secure position to reduce the chance of them getting loose and flying straight for my face (though that has happened a couple of times, so now whenever there is a stray fuzzy in the air around me, I duck for cover…little bit paranoid…) Below are some creepy cool pictures of my little friends tethered that I was able to capture using a low-intensity microscope.
I am fortunate enough to be able to purchase these mosquitoes (Aedes Agypti) from a research laboratory that specializes in bioassays of insect control agents for lab testing. So, getting them has been easy… but maintaining them in a lab setting has proven to be very difficult. Once I receive my little ones in the mail, they usually live about 3-4 days, so once they are no longer viable for testing, and as I wait for my next shipment, you can find me frantically running around Nicholas Arboretum attempting to catch some wild-type mosquitoes. I’ve gotten some pretty weird stares and even weirder questions when I lurk in bushes near the Huron River trying to catch my prey, but hey, anything for science!!!!
Five seconds after this picture was taken, I fell into a pond.
Although it sounds so exciting and desirable, running around the Arboretum with mosquito nets actually isn’t the best part of my project this summer! We’re just getting to the good stuff!
Once I got a few mosquitoes tethered and ready to go, I was able to start recording some of the awesome sounds these guys produce in free flight. That pesky buzz of a nearby mosquito is actually a love signal, a sound they produce and adjust in order to mate with one another! However, before recording these adjustments in their wing beat frequencies when placed within earshot of each other, I needed to record individual mosquitoes to build up my recording database that will help me clearly show the difference in base frequencies between male and female mosquitoes. Research has shown that females have a base frequency of about 400 Hz, while males are around 600 Hz, so the next stage in my research was to prove this phenomenon via data collection and analysis.
This preliminary data recording stage is still ongoing, but nearing its transition into recording mating pairs, as the data I have collected thus far is pretty spot on with the research! As with any scientific study, there will always be factors that make perfectly reproducing results from another research study challenging, so my goal was to get as close as possible, and I did!
Here are some samples…
Female
Male
When I was ready to start collecting data, I first focused on recording the wing beat frequencies of as many male mosquitoes as I could before nearing the end of their lifecycle. Thus far, I have obtained significant data from 9 male mosquitoes, where their base frequency was in range to what I anticipated (though slightly higher than the published data) and their harmonics are exactly as expected. Below shows one spectrogram of a male recording, as well as a graph showing the frequency distribution of all 9 male recordings during free flight.
Next, I moved my focus onto recording the female mosquitoes in free flight. These little ones were much harder to tether, for a number of reasons- their size, they didn’t respond as well to the cold water anesthesia so they kept waking up during pinning, and the insect wax didn’t solidify on their abdomen as easily as the males. All I have to say is if you see a million mosquitoes flying happily in our makerspace, don’t look at me!!!!
After overcoming that challenge, I was able to successfully obtain recordings from 7 female mosquitoes, though I tethered much more than that and for an unknown reason, many of the females in this batch wouldn’t beat their wings. The 7 good recordings I got are shown on the graph below in addition to one female spectrogram recording, with an identical format to the male distribution graph above.
Being super happy with this data, I wanted to take the analysis one step further to connect my findings with that of Ron Hoy, the professor at Cornell and mastermind behind all of this research. A figure that reappears throughout his research (pictured below) shows a clear spectrogram depicting the harmonic stack of sound clips from both male and female recording sessions.
My goal was to reproduce this figure with the data I collected thus far in my research. That figure is shown below, with a little extra color coding thanks to my OCD (red = female, blue = male)!
The rest of my research plan consists of obtaining more individual recordings to clean up the figure above, and then record mating pair interactions! All of these recordings will be conducted in a sound-proof box that I created, with a lid that has a laser cut track removed to allow for me to manually move the male mosquito in and out of the females hearing range throughout the duration of the recording. This procedure is to clearly reveal the altering of flight tones when the mating process begins.
Stay tuned to see where the next stage of my project leads! I can’t wait!
Hi! My name is Haley Smith and I just finished my senior year at Temple University where I studied bioengineering. I had an awesome first week at Backyard Brains, meeting all the fellows and familiarizing myself with the workspace and the BYB kits was a fun way to get started. I have extensive lab experience in the fields of biomechanical engineering, neuroengineering, and molecular/cellular engineering, all of which has helped prepare me for my unique project this summer: studying mosquito love songs! For my research, I will begin by designing methodology to record the frequency patterns of mosquito wings as they begin the mating process. I’m hoping through analysis of these patterns, I will be able to reveal key parameters and cues in the mosquito mating process. You can see in the graphic below (from the Cornell paper which inspired this project titled “Harmonic Convergence in the Love Songs of the Dengue Vector Mosquito”) how the female mosquito’s frequency changes over time to match the male’s…
Harmonic Convergence.
By understanding more about mosquito mating, the scientific community can come up with new ways to help control mosquito populations and limit the spread of mosquito-borne diseases. I am so excited to begin working on this proposed project by Dr. Ronald Hoy at Cornell University, department of neurobiology and behavior!
Presentation of my Senior Design Project, I’m third from the left!
Before beginning my fellowship position at BYB this summer, I worked under the supervision of a neuroengineering professor in a medical research lab at Temple University Hospital. At the lab, I worked primarily on my senior design project: engineering a nerve cuff electrode for the reinnervation of bladder function in individuals with spinal cord injuries and/or neurological disorders. Within this project, I utilized shape memory materials (specifically an Ni-Ti SMA alloy) embedded in the nerve cuff wall to facilitate surgical implantation, which worked thanks to a self-closing property of these materials under specific temperature thresholds. This idea came to me after discussing flaws with current nerve cuff electrodes used to restore bladder function with Dr. Michael Ruggieri, a professor of cell anatomy and biology at Temple University. Dr. Ruggieri dedicates his time and skills to work on NIH-funded projects in order to reveal pathogenic mechanisms of clinically relevant human disorders with the hopes of establishing clinical trials. His work on lower urinary tract denervation revealed many surgical implantation difficulties and complications, which inspired my idea of incorporating a shape memory alloy in the cuff design to help establish a more effective and efficient means of implanting such devices.
Through this research, I worked with MATLAB and utilized high-speed motion capture systems while also applying mathematic computations of body mechanics, forces associated with locomotion, and other engineering principles of physiological systems. These experiences and skills make me very confident I can invent methodology to study the mosquito love song and, after recording data, come up with some hypotheses and experiments to perform! It’s going to be an exciting summer! I can’t wait to get started!
