My experiment aims to test how two variables impact the likelihood of mosquitoes breeding. The first variable is the water type, and I am testing with tap water, filtered water, and muddy water from a local pond. The second variable is the food in which mosquitos will breed. Therefore, I will add rice water and sugarcane juice to the three water types. So, I will end up with nine mosquito trap containers shown below. Below are what each contains: A1) filtered water mixed with rice water; A2) tap water mixed with rice water; A3) muddy water mixed with rice water.
B1) filtered water mixed with sugar; B2) tap water mixed with sugar; B3) muddy water mixed with sugar.
C1) filtered water; C2) tap water; C3) muddy water.
My house was in plot id (9236) for AOI of 92; the area is mainly urban with primarily residential houses and occasional trees. The traps were all set up in the kitchen garden in our house's backyard.
My hypothesis was muddy water mixed with rice or sugar would be the best breeding ground for mosquitoes. My hypothesis was based on the fact that the carbon dioxide trail from sugar water or fermented rice water can lure in mosquitoes (similarly to being attracted to the carbon dioxide that people exhale). While some research suggests dust particles attract mosquitoes, I hypothesized that it would be a secondary variable.
I monitored the traps daily but kept a log of the changes twice a week, as seen in the picture below.
The first week, the days were hot and dry, with temperatures touching 100 degrees Fahrenheit. I did not see any activity in my traps outside of the ones with rice water (A1, A2, and A3) had a fermented smell, and the ones with sugar water had a color change, as shown in the picture below due to the caramelization of the sugar due to the sun rays.
During the second week, the days continued to be hot and dry, with temperatures touching 101 degrees Fahrenheit. I saw a dead fly and a dead mosquito in the A1 and A2 traps, which suggested a mosquito going through a complete metamorphosis (egg, larva, pupa, and adult) but did not survive in the rice water.
I also took a small sample of the A3 water and analyzed the selection, and saw mosquito larva and pupa, as shown in the pictures below. My B1 and B2 showed some algae-type formation and saw some bubbles. Nothing changed for the B3 trap or C1, C2, and C3. I did some sample reviews but haven't seen any mosquito habitat yet.
Week 3 and 4, the weather remained hot and dry and, except for some activity in the A traps, did not see much change. Did find larvae in A3 when I sampled the water, as seen in the picture below.
So far, my original hypothesis is proving correct, though I would have expected similar activity on the B samples, primarily B3. I did remove the green items after week three but did not see any change. One of the key learning is that temperature and direct sunlight have a big part to play in the mosquito habitat. I believe many mosquito eggs did not get to the larvae stage because of the water temperature in the traps. To prove this hypothesis, I am moving my traps to a place that will be entirely under the shade and not under direct sunshine.
Week 5 - 7 Update
During Weeks 5 through 7, the mosquitos were put under the shade to test the effect of water temperature. During the duration of the sampling, the weather was very hot and dry, but the mosquito traps were under shade. After putting the traps under the shade, I saw that there was an increase in larvae activity. Not only did I see activity in the A1 and A3 traps like in the previous weeks, but putting the traps under the shade also increased activity for the B traps. I saw that traps B1 and B3 showed larvae, unlike in previous weeks. The pictures and videos of the larvae that I found are shown below. Unfortunately, the C traps did not show any larvae activity throughout the seven weeks of sampling.
Mosquito Video 1.mp4
Mosquito Video 2.mp4
In conclusion, my hypothesis was correct. I saw that muddy water mixed with rice or sugar was the best breeding ground for mosquitoes. My expectation that the activity should be higher in sample B3 also proved true. The activity meant the carbon dioxide trail produced from sugar water or fermented rice water lured mosquitoes. However, in the earlier weeks, one of the problems I faced was seeing little larvae activity in any of my B traps. I believed that despite a carbon dioxide trail with the muddy water mixed with rice or sugar attracting activity, the water temperature was not helping larvae activity. This belief was derived from reading through the literature and finding that most studies showed that as the temperature increases, mosquito activity declines. I thought there would be more activity by putting the traps under shade. Therefore, I was not surprised when I saw that putting the traps under the shade increased the larvae activity. The second test proved my secondary hypothesis that the shade would help increase activity. This result indicates that the temperature of the water and the amount of direct sunlight affect mosquito activity in the mosquito habitat. A moist, shaded area with the rice or sugar food medium helped the larvae grow.
About the author: Aneesh is a senior at the Texas Academy of Mathematics and Science, Denton, TX. This blog describes a mosquito trapping experiment conducted as part of the NASA STEM Enhancement in the Earth Sciences (SEES) summer high school research internship. His 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/).