University of Minnesota

Ecology Fair University of Minnesota Monarch Lab

Abstracts from St. Hubert School 2001

St. Hubert School
8201 Main St
Chanhassen, MN 55317

Year: 2001
Teacher(s): Cindy Petersen

Beauty is NOT Only Skin Deep

Tara M

To set up my experiment, I raised approximately 50 monarch larvae into chrysalides. When they went into the chrysalis, I marked them on the day that they went in. After 1, 3, 5, and 7 days in their chrysalides, I froze five chrysalides.  I then took them to the hospital to be mammogramed to see what was inside of all of them. Then I dissected them by cutting them vertically down the center and recorded observations. The purpose of my experiment was to see the rate of growth of monarchs inside their chrysalides. I found out that after the first day, there was less liquid from their wastes inside of them than there was on the seventh day. I also found out that the abdomen gets bigger as they develop and red gonads are present early on in their development. I would still like to find out the rate of growth over a longer period of time because the weather was very warm, so they developed faster inside the chrysalids. I learned that there are many amazing things going on inside the chrysalis besides them just turning to liquid as some books say. Overall, I think that this was a very productive experiment.

Dazzling Daisies

Kelly O

In my experiment I set up a cage and put ten butterflies in it with five different colored flowers.  Then I recorded which flower they went to most often over a three day period.  I did this experiment to see how the color of a flower affects monarch nectaring. I found that most of the monarch went to the red flower to nectar.  All together 70% of them were on the red.  I wasnt absolutely sure about the results because two of the monarchs got out of the cage at one point. I learned that overall monarch butterflies like to nectar on red flowers and that things dont always turn out the way you plan.

Decisions, Decisions

Ali M

I put eight stems of milkweed (A. syriaca) in water tubes and arranged them randomly in a circle, placing them in a plastic pool filled with soil.  There were four different types of milkweed, two stems of each, healthy, yellowed disease and sprayed.  I then placed 20 larvae (stages 2-4) in the center of the pool and observed which milkweed they traveled to.  I repeated this three times on three different days. The purpose was to see how the different conditions of milkweed affected the preference of a monarch larva.   I found that they wandered around until they found any stem and they stayed there.  From the results I found they went to the sprayed first, yellowed next, diseased third and lastly they went to the healthy! The temperature of the outside in one of my uncertainties because that could have affected their level of activity.  I learned that the larvae don't appear to sense any differences in the types of milkweed they traveled to.  I also learned that the older the larvae are, the quicker they choose a milkweed plant.

Marvelous Milkweed in the Meadow

Kyle K, Ben W

For seventeen weeks over the summer, we went out to Spring Peeper Meadow in Chanhassen, Minnesota to record the density and abundance of milkweed plants (Asclepias syriaca). The meadow was divided into three parts: the pathway, the middle and the hillside for comparison. We recorded the height, presence of buds, flowers or seed pods, the herbivory rate and the condition of milkweed at each site.  At the end of the milkweed season (9/7/01), we went out in the meadow and counted the number of seed pods on the milkweed plants, the plant height, and the rate of herbivory. The purpose of this experiment was to measure the condition of milkweed over the growing season and compare these conditions at the three different sites within the meadow. The results of this experiment are pending at the time of press.  We have not fully analyzed the data.

Mating Extravaganza

Katherine C

I set up four tents with different light conditions.  One tent was in eight hour of light, another in thirteen hours of light and two under seventeen hours of light.  One of the seventeen-hour light cages had milkweed in it. My purpose was how do different light conditions and the presence of milkweed affect monarch mating behaviors? The seventeen-hour cage without milkweed had the first mating pair, the seventeen-hour tent had the second mating pair and the thirteen-hour cage without milkweed had the last mating pair.  There was no mating in the eight-hour tent after two weeks and five out of ten died. I was concerned about the high mortality as the experiment went on. I learned that the monarchs dont seem affected by the presence of milkweed and they need more than eight hours of light for mating.  They will mate in thirteen hours of light, but it takes longer.

Milkweed Mania

Theresa W, Emily D

In our experiment, we used three different types of milkweed; Asclepias incarnata, Asclepias syriaca, and Asclepias verticillata.  We put thirty second and third instar monarch larvae and placed ten on each milkweed.  We then measured and recorded larval growth every other day for eight days.  When the larvae went into their chrysalides, we measured the length of them.  When they emerged as butterflies, we weighed them.  In our experiment, we wanted to find out how the type of milkweed affects larval growth over time. In our experiment, we found out that monarch larvae die when eating A. verticillata.  The larvae on A. incarnata, and A. syriaca both did very well and grew a lot.  On A. incarnata, they grew an average of 21mm.  On A. syriaca the average was 20mm.  For average length of chrysalides, A. verticillata had the average length of 0 because they all died, A. syriaca had an average length of 26mm and A. incarnata had an average length of 22mm. An uncertainty we had was that we may have had a virus that caused some of our chrysalides and adults to die.  Another uncertainty we had was the temperature of living conditions.  We had this uncertainty because we switched taking care of the larvae and they were in different houses. From our experiment, we learned that monarch caterpillars prefer and grow better on A. incarnata and A. syriaca, and dont grow well on A. verticillata.  We also learned that there are many different types of milkweed in the world and monarchs eat tons!

Monarch Density

Samantha S, Joy M

For seventeen weeks over the summer, we went to the Spring Peeper Meadow and recorded the number of eggs, instars, and adults at the three different sites (meadow, pathway and hillside.)  We also recorded the plant height, condition, and amount of herbivory for the milkweed at the three different sites.  We wanted to compare the density of monarchs at the three areas over time, and we wanted to find out if adult females chose average, or above average plants to lay their eggs on. We found out that there was a peak in monarch the whole site, at the end of May to the beginning of June.  Second and third peaks appeared from mid July to the end of August.  The three sites differed in the number of eggs and larvae from week to week.  We are in the process of analyzing our milkweed data at this time.

Monarch Ovipositioning Extravaganza

Renee K, Sara E

For experiment one, we had twelve pregnant female monarchs.  We put them in a six by six foot tent outside.  The tent had seven different species of milkweed.  They are:  Asclepias incarnata, Asclepias curassavica, Asclepias verticillata, Asclepias eriocarpa, Asclepias exaltata, Asclepias syriaca, and Asclepias fruticosa. For three hours we observed monarchs ovipositioning  and the number of eggs laid on each plant.  For experiment two, we gathered ten pregnant monarchs in the tent and placed A. syriaca and A. incarnata alternately in the tent.  We put two Ascepias syrica and two Asclepias incarnata every other.  For four days, we recorded how many eggs were laid on each species. For experiment one, we wanted to see which species of milkweed: A. incarnata, A. curassavica, A. verticillata, A. eriocapa, A. exaltata, A. syriaca, and A. fruticosa the female monarchs would prefer for oviposition. For experiment two, we wanted to see which species of milkweed out of A. syrica and A. incarnata the female monarchs would prefer for oviposition. The monarchs laid eight eggs on A. curassavica, seven eggs on A. eriocarpa, nine eggs on A. incarnata, one egg on A. verticillata, six eggs on A. syriaca, A.fruticosa: one egg, and ten eggs on A. exaltata.  The total amount of eggs was 42.  For experiment two, A. syriaca had 238 eggs and A. incarnata had 278 eggs.  The total amount of eggs was 516. Some of our uncertainties were that some of the eggs fell off the plants and we didnt end up counting them, we may have miscounted, and we had two different locations for the experiments. We learned that monarchs prefer to lay their eggs on A. exaltata and A. incarnata in the first experiment.  For the second experiment, we learned that monarchs preferred to lay their eggs on A. incarnata.

The Great Weight Race

Katie K

First I set up my monarch cage and then brought the cage home.  After that I weighed them and recorded each butterflys weight.  Finally I nectared them.  In this experiment I wanted to know if different kinds of nectars would affect a monarch butterflys weight and health. In my experiment my three nectars were kool aid, sugar water, and honey water.  In order from the most weight, average weight gain start to finish was first honey water, sugar water and then the least kool aid.  From this experiment, I can conclude that the honey water was the healthiest and makes the butterflies weigh the most. An uncertainty I had was that they lost wings which would affect their weight.  Something I learned was that honey water was the best for their weight and health.

Totally Tachinid

Laura N

Tachinid Fly parasitoids are a major cause of mortality in Monarch caterpillars.  Phase 1 of my experiment consisted of placing thirteen Monarch caterpillars, for each stage, in a mesh cage with 15-17 adult tachinid flies.  I allowed the flies to parasitize the caterpillars until they molted to the next stage, when I would remove them.  I then raised the larvae to adulthood and recorded the rate of parasitism for all the instars.  Phase 2 had me placing ten caterpillars, two for each stage, in a cage with seventeen flies for a two-hour time period.  I then removed them and raised them until I could record the parasitism rates.  The purpose of my experiment was to find out the rates of parasitism of the tachinid fly on the five larval stages of the Monarch butterfly caterpillar. I found that in Phase 1, the flies had almost no preference in what stage they parasitized, but the majority of caterpillars were parasitied in the third instar.  In Phase 2, all the stages had at least one parasitied caterpillar after the two-hour period. I learned about a fly that I didn't even know existed and I feel that I have contributed greatly to the world of Monarch biology with my findings.

Where is the Milkweed?

Catherine B

First, we put in one milkweed plant, three green paper leaves that hung from the top of the tent, a pathos plant, and a green cloth in the green tent. We put in ten pregnant female butterflies in a green tent with the milkweed, green paper leaves, the pathos plant and green cloth.  We observed the butterflies each day and we counted how many eggs were on the green items. We wanted to find out how do different green materials affect the frequency of monarch egg lying. We found out that they prefer to lay their eggs on the milkweed. When there are too many eggs on one milkweed or they are desperate to lay eggs, they will lay their eggs on other green items. All together they laid 131 eggs. On the milkweed they laid 119 eggs, there were three eggs on the green paper leaves and one on the tape on the bottom that was holding the leaves down. They laid two on the pathos plant and we found six eggs on the green tent. On the green cloth we did not find any eggs. One thing that were unsure about is if we counted the right number of eggs on the milkweed because there were so many eggs on it. We are also unsure that the height of the items might have made a difference in egg laying because the green cloth was at the bottom and the milkweed, green leaves, and pathos were all off the ground. We learned that monarchs get very desperate to lay eggs in a cage and will start laying on different things, even tape and soil that are not green.

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