Experiment

We decided to set up an experiment to test whether our mealworm/darkling beetles (scientific name Tenebrio molitor) prefer a light or dark habitat. We based this off our observations that the mealworms and beetles seem more active in the dark; they come to the surface of the oats and actually move around rather than burrowing out of sight.



Research question: Do mealworm(darkling)beetles prefer to be in the light or dark?

Trial 1 Observations

We placed 20 beetles near the center of a cooking pan and then covered half the pan with a dark piece of paper to block the light from a small desk lamp we placed over it. We watched them for a total of five minutes. After only a few seconds the beetles started to migrate to the "dark" side of the pan. There was one beetle that went the opposite direction, but after running into the pan wall, it turned around and scurried under the paper as well. The beetles remained under the paper for the duration of the five minutes.

Trial 2 Observations

We uncovered the pan and scooted the beetles (who had congregated in one dark corner) toward the center of the pan. Then we placed the paper over the opposite side of the pan for this trial to avoid any directional bias. Again, we waited for five minutes, but the beetles rushed under the paper to the dark side of the pan even faster than before and never came back out.



It would seem our beetles prefer the dark!

A Realization!

So, I had a realization just barely. Remember how I just never wanted to clean out the dead skins from the pupa?  Well, I'm realizing now that they disappeared. And remember how I said they never eat?

EW, GROSS, SICK, NASTY!! Do you think they ATE the dead pupa and skins? Probably. Canibalism.

Another observation. Our beetles have been mating like CRAZY. Seriously guys, get a room. They are just mating all day every day. I'm worried that there might be a massive explosion of baby worms sometime in our near future. Brace yourselves.