Mealworm bonanza!

Elementary Science

Justin Upshall, Josie McConnell & Jennifer Kay

Table of Contents

INTRODUCTION 3

OBSERVATION – PHASE 1 3

THE EXPERIMENTS (PHASES II AND III) 5

EXPERIMENT 1 - FEELS LIKE HOME. 5EXPERIMENT 2 - HOLD ON! 6EXPERIMENT 3 - JAILBREAK! 7EXPERIMENT 4 - UNDER THE SPOTLIGHT! 8EXPERIMENT 5 - THE GREAT ESCAPE 9EXPERIMENT 6 - HOT OR COLD, BABY? 10EXPERIMENT 7: TOLERANCE OF DIFFERENT SUBSTRATES 11EXPERIMENT 8 - THIRSTY BUGGERS! 13EXPERIMENT 9 - DRUNK FUNK 14EXPERIMENT 10 - SINK OR SWIM? 15

CONCLUSION: 17

Introduction Over the course of four weeks, a scientific inquiry of mealworms was undertaken. Many observations, predictions, hypotheses, and experiments were performed to discover more about the mealworms. Using the scientific method described by Abruscato, many preferences of mealworms were discovered, and their attributes and abilities were identified.

Before describing each experiment, below are some initial observations about the mealworms and the environment they were kept in through the inquiry process. Also included is a description of the metamorphological changes that the larval mealworms undertake.

Observation – Phase 1

Elements of the system/home:

Cut up, dried leaves (natural habitat, hide in and eat it?) Wheat bran (hide in and eat it) Meal worms Apple pieces (2 small) Stick

The mealworm’s physical characteristics:

It has 6 legs. It has 13 segments It has two little antennae It has small claws at the mouth Head - one upper part (visor) and two “labia” just below that part. It has two tiny hairs on posterior end (used for gripping onto things)

Measuring:

The mealworm is, on average, 26 mm long. The segments in the middle of the body are the longest, and decrease in size toward the

anterior/posterior. The habitats, touching at the middle are 41cm2 each. This means that each meal worm,

if all located in one of the habitats, would have about 5cm2 each.

Communicating:

The mealworms seem to keep their distance from one another.

Classifying:

Habitats: natural (leaves, debris, stick) and unnatural (bran

Kingdom: Animalia

Phylum: Arthropoda

Class: Insecta

Order: Coleoptera

Family: Tenebrionidae

Genus: Tenebrio

Species: molitor

The mealworm will begin metamorphosis over the course of the four-week inquiry. The three stages of the mealworm life-cycle include: larvae, pupae, and beetle.

Week 3: Begin Molting!

Five of the mealworms have molted their exoskeletons, and are now hard-shelled again.

One of the mealworms has begun a metamorphosis. His color is more pale, and some of its segments have fused (near the head). His legs have curled and stiffened. Eyes are apparent on the head. Spikes protrude from the side. This stage of the metamorphosis is called the pupa.

The pupa is able to wiggle, but cannot eat or poop.

Week 4: More Metamorphosis!

2 beetles

9 molted exoskeletons

1 pupa

6 larvae

1 “deady bones” (deceased)

The Experiments (Phases II and III)

We began placing colored identification tags with nail polish on our larvae.

Experiment 1 - Feels like home.

Inquiry:The mealworms will have a choice between 2 environments in their living box: natural (leaf litter/debris) and unnatural (bran). Which side will they prefer?

Hypothesis:Mealworms will prefer their evolutionary natural environment (leaf litter/debris); therefore, they will gravitate to the leaf litter section of the box.

Experiment:The mealworm’s living space is divided into two habitats:Natural and Unnatural. The ‘natural’ habitat has been formed based on the organism’s preferred habitat in nature: soil and debris. Each habitat is the same area, and passage between each habitat is allowed. Two apple pieces are placed in the middle, so that neither side is preferred due to apple access. The apple provides food and hydration to the mealworms. The habitats are both dark due to there being a cover on the box. Each time the box is opened the number of mealworms on each side will be recorded.

Variables:Bran environment versus leafy environment.Both sides are dark due to the cover on the box.The apple is accessed equally from either side.

Numbers:There are two habitats.There are 8 mealworms. There are two pieces of apple.

Results:

Leaves: BranDay 1: 7:1Day 2: 5:3Day 3: 6:2Day 4: 2:5 - One of the meal worms began metamorphosisDay 5: 4:3Day 6: 6:1Average: 5:3

Conclusion:The mealworms preferred to stay on the natural (leaves/debris) side of the box. This confirms our hypothesis that the mealworms prefer their natural environment over the bran, even though the bran acts as a similar environment to their natural one.

Experiment 2 - Hold On!

Hypothesis: Mealworms will be able to grip different substrates with varying ability. Mealworm larvae will fall sooner on sandpaper than on a sponge because there are more holes on a sponge to grip onto.

Description of Experiment:Six mealworms will be placed on sandpaper one at a time. The sandpaper will be tilted to see when the larvae fall due to the slope. The experiment will be repeated using a sponge.

Controlled Variables:Angle was increased at a steady rate for all trials. A different mealworm was used for each trial to avoid fatigue and overhandling. Test Variables:The test variable is the material: sponge vs. sandpaper.

Sandpaper: Sponge:

Trial 1: 30 degrees 110 degreesTrial 2: 45 degrees 180 degrees!Trial 3: 25 degrees 180 degreesAverage:Sandpaper: 33 degreesSponge: 157 degrees

Discussion: It was observed that the mealworm can use its six legs to hold onto a substrate, and it also uses a small forked structure at its posterior to grip onto substrates. When the mealworm is upside-down it cannot move along the sponge without falling. This is because it cannot get its tail back up to hold on again once it lets go.

Conclusions:The sponge allows for a better grip for the mealworms to hold onto. Mealworms are able to grip substrates upside-down which will enable them to explore diverse habitats in nature.

Experiment 3 - Jailbreak!

Inquiry:Will mealworms try to escape a trap? Will threat of danger make them try harder to escape?

Hypothesis:Mealworms will have greater success in escaping a challenging trap when they are threatened or agitated. Threat in the form of humans handling them will increase their motivation to escape.

Experiment:The mealworm was trapped in the handle (circle) of a pair of scissors. The same mealworm was handled and placed back in the scissors. Observations were made to assess their ability to escape from the trap.

Observations:First attempt:

The mealworm circled around twice. It then attempted to circle around backwards. The meal worm was released and other activities were performed with it. Second attempt:It was observed that the mealworm was more active in its movement from being played with. When the experiment was repeated, the meal worm immediately made his way over the edge of the scissors, freeing itself.

Discussion: This was an incidental experiment. One variable that was not controlled was light. The second attempt of the experiment, the mealworm was under a bright light. Could this have accounted for the change in result? We know from other experiments that mealworms tend to stop when exposed to light, however the opposite reaction has been observed.

Conclusion: Mealworms seem to be motivated to escape by manipulation/threat of danger. Results are not conclusive because light was an unintended/uncontrolled variable.

Experiment 4 - Under the Spotlight!

Inquiry:We will time two mealworm larvae and two mealworm beetles as they travel a narrow passage between two meter sticks. One of the mealworms will be exposed to a bright light for the duration of the race. How far will they make it in 1 minute? How do mealworm beetles compare to mealworm larvae?

Hypothesis:Mealworm larvae have preferences between light and dark environments. Based on the fact that in the natural environment mealworm larvae burrow underground, it is hypothesized that the mealworms that are exposed to the light will move faster to attempt to get away from the light, and move more quickly through the racetrack.

Controlled variables:All variables, such as transport/manipulation of mealworms (larvae and beetles), space between the rulers, and brightness of the light were controlled. The experiment is performed in a dark room.

Test variable:The only differing variable is the introduction of a bright light to one of the two test subjects in each trial.

Results:Larvae:Trial 1: Trial 2: Trial 3:Light: 34 cm (yellow) 0 cm (red/green) 25 cm (pink)Dark: 14 cm (green/yellow) 36 cm (green) 50 cm(blue)Average:

Light: 20 cmDark: 33 cm

Beetles:Trial 1: Trial 2:Light: 20 cm 0 cmDark: 56 cm 70 cmAverage:Light: 10 cmDark: 63 cm

General Observations and Discussion:The larvae in the light tended to one side of the meter stick where there was some shade. Trial 2 the mealworm who was exposed to a bright light climbed up onto the meters stick a little. Sometimes the larvae would stop completely, and other times they would run fast, as if to escape the light. The beetles stopped-short as soon as the light was shone on them.

Conclusions: When under light, the beetles and larvae tended to stop, as if in fright. Although this wasn’t the case in all trials, we conclude that the larvae are slightly affected by the light, and the beetles are very inclined to stop and be still under the bright light. In nature, this will prove as a disadvantage for the mealworms when they are exposed to light, as predators will more easily capture them as prey.

Experiment 5 - The great escape

Background: We wanted to experiment with the social interactions of the mealworms. We noticed that in their living quarters they tend to keep a distance from one another, but when we experimented with them they sometimes gathered in a group. We became curious as to whether some sort of social interaction was taking place. To do so, we constructed an escape scenario, similar to the previous experiment, except that it would require cooperation. Inquiry: Can mealworms work together to escape?

Hypothesis: Mealworms will not be able to work together to escape because they do not have the cognitive faculties to plan and coordinate together.

Methods: A paper trap was constructed. The only possible escape would be to work together, using their

collective weight to reduce the angle of the sides in order to attain the necessary grip to climb out.

Results:The mealworms surprised us. They very quickly gathered in the corner of the paper box and proceeded to escape by weighing down and deconstructing the flimsy box corner.

Discussion:We realized after our experiment that they may have a built-in instinct to copy one another rather than actually coordinate. However, the results clearly revealed a social interaction process of some sort, whether it was copying or coordinating.

Conclusion: Mealworms socially interact. They may or may not experience a sense of community as part of their collective evolutionary strategy.

Experiment 6 - Hot or cold, Baby?

Inquiry:Do mealworms prefer hot or cold environments?

Hypothesis:The larvae will tend to go to where it is warmer, as it is warm (insulated) underground in their natural habitat.

Experiment:Six mealworms will be placed in a closed environment with a glass of hot and a glass of cold water. The experiment is to determine whether they display a preference for a certain temperature.

Variables: Hot vs. Cold environments.

Results:All larvae gathered as far from the warm as possible (extreme corner of the box), except 1 larva which settled halfway between the two cups.

Discussion: This experiment could be repeated with an in-depth study of temperature preferences. Many different temperatures could be tested to determine more precisely their temperature preferences.

Conclusions:Mealworms prefer the cool environment to the very hot one. The fact that one mealworm stayed in the middle of the two cups may imply that there is a specific temperature that is in between the two temperatures tested. Further study would have to be done to determine their exact temperature preference.

Experiment 7: Tolerance of Different Substrates

Inquiry:We have already discovered that mealworms have preferences for substrates in which they can burrow. To explore this further, an experiment was undertaken to discover their ability to tolerate standing on different unnatural substrates. This exploration will also determine the preference between these two substrates of the beetle.

Hypothesis:When forced to stand on playdough and a sponge, a mealworm will tolerate being on the sponge longer, as the texture of a sponge resembles the natural environment of soil more than playdough does. Because beetles venture onto a variety of substrates in their lives, they may show less of a preference than the mealworms do.

Controlled Variables:The control in this environment involves placing mealworm in a 25cm2 environment of bran, as we know this is an environment they tolerate well. Test Variables:The two test variables are a 25 cm2 sponge substrate and a 25 cm2 playdough substrate.

Results:BranPupae BeetleTrial 1: 93 sec 16 sec2: 72 sec 9 sec3: 44 sec 11 secAvg: 69 sec 12 secPlaydoughLarva BeetleTrial 1: 35 sec 1: 2 sec.2: 17 sec 2: 2 sec.3: 12 sec. 3: Stayed on bottom cornerAverage: 21 sec Avg: 2 secSponge1: 25 sec. 1: 2 sec.2: 60 sec. 2: 2 sec. 3: 45 sec. 3: Stayed on bottom cornerAverage: 43 sec Avg: 2 sec

Discussion:By considering the average times for the larvae, they seem to prefer staying on the sponge longer than the playdough, by an average of about double the time. The data shows also that the mealworms would stay in the bran for an average of over a minute. The beetles seemed to struggle when walking around in the bran, almost as if they had no grip (like walking on sand). The beetles all ran and jumped off of the test substrates almost immediately - until the third trial, when they climbed down the side of the substrate and held on to the bottom corner of the item (see figures).

Conclusion: It can be concluded that the pupae do in fact have a preference for the bran than the other two substrates. Between the two test substrates, the mealworms showed a stronger tolerance for being on the sponge rather than the playdough. The beetles stayed on the bran for slightly longer than on the test substrates, however this may be due to their difficulty walking on the substrate. The data does reinforce the hypothesis that beetles show less preference for different substrates, as they stayed on both test substrates for an average of 2 seconds. The third trial, where they stayed on the bottom corner for over a couple of minutes may show that they learned that they do not like to walk on the table, so they stayed on the test substrates to avoid this.

Experiment 8 - Thirsty buggers!

Background: We had a potato and a piece of apple in the box. Both seemed to be moldy so they were removed from the box.

Inquiry:What will happen when the mealworms do not have a source of moisture? (eg. apple/potato)

Hypothesis:They will become lethargic and possibly die due to lack of hydration.

Controlled Variables:There is still access to bran (which contains limited moisture). The mealworms are now all at different stages of development, within the box there are larvae, pupae, and beetles.

Experiment:The apple and potato were removed from the box and the mealworms were left over the weekend. When the mealworms were checked on the following Monday there were 2 dead specimens and one mealworm was caught in the act of eating another.

Conclusion:Before dying the mealworms will turn on one another, eating their companions for a source of moisture. They have no sense of community.

Experiment 9 - Drunk Funk

Background: All beetles and mealworms in the box were very thirsty. We had just discovered the unfortunate cannibalism phenomenon. At this point, we had only two beetles, one larva, and a pupa remaining.

Inquiry: Will the mealworms consume alcohol if it is offered to them? Will they get drunk?

Hypothesis:1) Thirsty beetles and mealworms will drink gin 2) Following gin consumption, mealworms and beetles will display symptoms of drunkenness similar to those of humans and other animals, including observable lack of coordination.

Methods: The beetles and the larva were placed in the lid of the box. (The larva was left out of this experiment because it does not have an active digestive system). A large drop of gin was placed beneath each of their faces. The mealworm and one of the beeltes immediately began visibly drinking the liquid. The second beetle avoided the puddle but after being coerced through multiple physical re-orientations, it too drank the liquid. The creatures were then observed and filmed.

Observations: The coordination of all test subject was significantly impaired following the consumption of alcohol. Within five minutes the beetles were so drunk they could no longer stand up. The flipped over on their backs, and when kindly human fingers intervened to upright them they fell over sideways and onto their backs again. The larva appeared to be unaffected, but upon closer inspection it became clear that its little legs were moving but it was not advancing forward. It too had lost its ability to walk.

See attached video to view results.

Conclusion: Mealworms larvae and beetles get drunk when they consume alcohol.

Experiment 10 - Sink or Swim?

Inquiry: Can beetles swim? Will they choose to swim if given the choice?

Hypothesis: The mealworms cannot swim as their sphericals will fill with water and they will drown, thus the

beetles may have similar traits and will not be able to swim. We are prepared to perform quick lifesaving measures.

Methods:A tin pie pan was filled with a small pool of water on one side and the beetles were placed on the dry section of the pan. The beetles stayed on the dry portion of the pan until we forcefully placed them in the pool section. Once immersed in the water the beetles managed to stay above water by performing a flailing motion that resembled a beetle doggy-paddle.

Observations:At the beginning of the experiment it looked like the beetles were not breaking the surface tension of the water, but in fact the beetles were swimming and could move around quite quickly in the water. The beetles did not want to swim, and could not get out of the water without assistance.

Conclusions:Beetles can swim, but would prefer not to. They would drown if left in the water.

Conclusion: Mealworms provide a fantastic basis for science exploration and experimentation. Throughout this project we engaged in the three basic types of inquiry: observing, predicting and inferring. Mealworms are an inexpensive and engaging project to complete with any class!

Wiki link:https://mealwormsinquiry.centraldesktop.com/mealworminquiry/file/30274673/