RESEARCH UPDATE: IMPACT OF TEMPERATURE AND LIGHT EXPOSURE ON GROWTH RATE OF MEALWORMS

Research Update:

Impact of Temperature and Light Exposure on 

the Growth Rate of Mealworms

Group Members: Josselin Chambily, Travis Friesner, Bishoy Galil, Hiu Nam Wong

Research Question & Hypothesis

Do temperature and light have any effect on the growth rate of mealworms? We hypothesize that temperature and light will have an effect on the growth rate of mealworms. Testing this hypothesis we want our research to find out what factors contribute to their ideal habitat. Moreover, we predicted that mealworms that are nurtured in the dark at 72^oF will grow the fastest compared to mealworms put under different conditions. Our main question for that project is how temperature is important for the rate of growth of mealworms.

Discussion

o    Describe what you have found so far in terms of trends in your data.

We have found that temperature and light do affect the growth of our mealworms. Even if the effect of temperature is more obvious than the presence of lights, we can notice than the population exposed to higher temperature and constant light grew larger while the population conserved at low temperature in the dark shows the least amount of growth for the first 3 days. After this first period of time, their growth didn’t change as we expected: So far, we have found that all the populations grew bigger and heavier for the first 3 days, then all started to decrease in mass and size. A possible explanation could be the fact that mealworms are preparing for pupation, which is the next stage of their life cycle (we even observed few small and light pupae in some populations). To sum up, even if our mealworms decreased in size and mass around the end of our experiment in an unexpected way, we can clearly observe a trend where our mealworms grew more when they were exposed to light and conserved in higher temperatures.

o    What challenges or surprises did your group encounter?

First, it is hard to control the population growing conditions. We figured out that the room temperature is greatly affected by the weather. We aimed for a room temperature that is about 25^oC hoping for a more obvious growth, yet the room temperature was about 20^oC and fluctuates depending on the weather. Also, since part of our mealworm populations will be put under lights 24 hours, the heat from the light increases the temperature as well. Next, we have to figure out how to provide light source for enlighten populations that are put in incubator or fridge (which are dark when you close the door), ultimately, we had to buy LED lights from dollar stores and put them next to the mealworm populations, at the same time risking that the lights will die out during weekend. One surprise and challenge we faced after the first weekend, is that the mealworm populations put in 37^oC molded badly, and all the mealworms were dead. We quickly concluded that 37^oC was too high for mealworms, and changed the “higher temperature” population to a 27^oC incubator.

o    What advice or solutions do you have for other groups?

 All groups need to be prepared for their experiments, as we can see that the experiments many times don’t go with our predictions. Thus, every group should make sure to have enough time is anything doesn’t go with their predictions. Moreover, every group should do their best trying to use precise instruments for measurements. Also, the measurements need to be taken more than one time to reduce the effect of error on the results. Let’s say that we are doing science, so it’s possible if we got imprecise results. So, every group has to think about limitations and try to organize the experiment considering those limitations.    

o    What will you discuss in your error analysis section of your discussion?

We faced many challenges during our experiment. To begin, keeping the temperature constant for the populations throughout the whole experiment was really hard; extended periods outside of the incubator during growth measurements may be an error that affected our results. The 24 hours lights had an impact on surrounding temperature of the populations as we noticed that the temperature under the lights was actually 28^oC rather than a desired 25^oC. Because of this additional heat from the lights, there was a temperature difference between the light and dark populations. Moreover, high humidity promoted mold growth that caused mealworms to die in the high temperature populations. Also, the nutrients we used, like potatoes and carrots, were not of the same mass which could affect the growth of our mealworms. The unequal amount of food supply might favor mealworms’ growth in populations that had more food, which leads to inaccurate results. Our experiment might have faced many human errors as measuring the length of the worms were very hard to be precise.

What question(s) do you have for other groups?

How did your group make sure your variables remains constant, or at the desired level/measurements?

Do the data your group obtained support your hypothesis?

What are some surprising findings?