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Cannibal Mosquitoes: Experiences from a 2021 SEES Intern

Paxton C, spent the summer of 2021 involved with a virtual NASA internship, the STEM Enhancement in Earth Science (SEES) Program, through the Texas Space Grant Consortium. More specifically, I am working on the GLOBE Mosquito Mappers Earth Explorers Project, where I am studying mosquito habitats and vector-borne disease alongside mentors and fellow interns from all over the nation.

To get going with the internship, our mentors directed us to set up our own local ovitrap experiment. I decided to investigate the effect of natural bait type on the oviposition preferences of Central Virginia’s mosquitoes. To accomplish this, I selected grass, clover, and pine needles as baits, and I built the traps in three large, black buckets. By weighing out the same amount of each bait, 0.25 ounces, I was able to control any confounding variables and manipulate just one- natural bait type. I put each bait in the corresponding bucket, set one large rock on top of each sample of bait, and then filled the buckets with three liters of water. To finish these traps, a flat wooden ruler was placed sticking out of the water for each trap. With the traps completely built, I set them out in the backyard of a neighbor. The location is well-shaded, surrounded by trees, and undisturbed.

The main data collection for the first trial with these traps took place on June 24, 2021. Instead of estimating, I decided to systematically count the visible larvae, egg rafts, and adults for each by scooping water into a smaller, white container repeatedly. I counted and then added all the numbers together at the end. The most interesting discovery I made during this process was that there were two cannibal mosquitoes in the trap containing pine needles! One of the Toxorhynchites spp. is pictured. The other image shows the tail end of the cannibal. These mosquito larvae were quite large; they barely fit under the clip-on microscope for my cell phone! An additional photo can be seen that provides a size comparison. In doing some research about this type of mosquito, I learned they do not bite humans because they receive enough sustenance from their fellow mosquito larvae. I found it quite interesting that the cannibals were only present in the pine needle trap. One can reasonably deduce that the non-cannibal larvae count was likely much higher than measured since the Toxorhynchites spp. are capable of eating thousands of larvae before they mature into adults. One can also see from the photos that the Toxorhynchites spp. are much larger than the other larvae, as well as their striking red color. In studying them, I noticed that they have pincers at their front to aid in the eating and capturing of prey.

I am now in the process of performing repeated trials for this experiment in order to (hopefully) solidify the trends that have emerged among the various natural bait types. I have been keeping a close eye out for any more cannibal mosquitoes that decide to make a home inside my traps. Lastly, I am grateful for this opportunity to engage in true NASA research. I have learned so much thus far, and the experience is far from over.

 

Paxton C. is a high school student from Virginia who is working on a research project this summer using the GLOBE Observer Mosquito Habitat Mapper. Her virtual internship is part of a collaboration between the Institute for Global Environmental Strategies (IGES) and the NASA  Texas
​​​​​​​Space Grant Consortium (TSGC) to extend the TSGC Summer Enhancement in Earth Science (SEES) internship for US high school (http://www.tsgc.utexas.edu/sees-internship/). She shares her experience this summer in this guest blog post.is a rising senior from Maggie Walker Governor’s School, Virginia, and a 2021 STEM Enhancement and Earth Science (SEES) Intern with NASA and the Texas Space Grant Consortium. She is currently part of the SEES Earth Explorers- Mosquito Mappers team.  

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