University of Minnesota

Ecology Fair University of Minnesota Monarch Lab

Abstracts from Other 2000

(Various), MN

Year: 2000
Teacher(s): Annette Strom

Effects of Common Garden Chemicals on Monarchs and Other Invertebrates

Tara C, Olya P

The question "How do common garden chemicals effect monarchs and other invertebrates?" arose out of our concern about perceived overuse of garden chemicals in our area. Our hypotheses were that garden chemicals would have an effect on invertebrates both above and below the ground. We tested our hypothesis by setting up twenty 1m x 1m plots. Then five plots each were treated per the bottle instructions with common fertilizer, herbicide, and pesticide. Five plots were left untreated. Once a week for four weeks the plots were checked and data about each was recorded: The number of milkweed plants was counted and their condition surveyed. Each milkweed plant was also observed for the presence of monarchs and the stages of those monarchs. Sweep nets for each plot were collected and the number of insects in each class was counted. 8 cm deep core samples were taken from each plot and the underground invertebrate phyla were counted. Our results show that fertilizer has some positive and null effect. Pesticide has both negative and null effect. Herbicide has a negative effect on all areas tested.

Temperature Extremes Affect Monarch Larvae

Abby P

The problem researched is how do temperature extremes affect monarch larvae. From past observations, there were many possible hypotheses: monarchs will move away from the temperature source, they will move towards the temperature source, they will eat more, they will eat less, they will curl into a ball, or the null hypothesis that temperature extremes will have no effect on monarch larvae behavior . Larvae were put in two extreme temperature environments. The heated environment was a heater set at 80 degrees Fahrenheit and the cold environment was an iced environment at 32 degrees Fahrenheit. Larvae were placed in environments and their behaviors were recorded. Many behaviors were observed: In the heated environments behaviors ranged from motion towards the heat source to moving away from it. Also, a few exhibited a dancing type motion. An unexpected physical effect was a greenish gel that came out of the spiracles. Reactions in the colder environment were less extreme, yet ranged from moving away from the temperature source to curling up in a ball. The study is inconclusive and should be done again with a larger sample size. Perhaps behaviors are dependent on the individual larva. Further research could also be done to find out more about the substance emitted from the larvae's spiracles.

Territorial Boundaries of Monarch Larvae

Matt C, Zach E

Observing individual monarch larvae, the questions arose about how the larvae would react if placed in close proximity with other monarch larvae, and if those reactions would be the same if the larvae were in close proximity with other invertebrates. The hypotheses were that monarch larvae would fight over food with other larvae and exhibit defensive behaviors towards other invertebrates. 40 larvae were first put in a 10 cm x 15 cm x 29 cm container with only three leaves of milkweed. Types of behaviors were observed, counted and recorded for one hour. This process was then duplicated, first adding ants, then a spider, and then a dragonfly, each for a period of ten minutes. The findings indicated that monarch larvae seem to show greater aggression towards each other than they do towards other invertebrates when placed in close proximity. Further research may show that the monarchs' coloring is a defense mechanism against other invertebrates, so their natural instinct is not to be aggressive towards them.

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