The Effect of Temperature on Caterpillar Development Rate

1. The Effect of Temperature on Caterpillar Development Rate uuuuuuuuuu DISCUSSION AND CONCLUSION INTRODUCTION RESULTS Our conclusion was that we rejected our null hypothesis because temperature did affect the growth rate of the painted lady butterfly. The heating pad in our treatment group malfunctioned over the weekend, and the temperature increased from 25oC to 31oC. This caused the food to dry out, and the caterpillars were dead when we found them. Too much heat killed the treatment group, and stopped their growth completely. Other future experiments could be done to further tell us about caterpillar growth and development, but this time more precautions would have to be taken to prevent accidents that gave us unexpected results due to equipment error. We expected caterpillars given more warmth to pupate more quickly than those in a cooler environment, but we did not foresee the death of the individuals in the experimental group. One of the principal parameters of thermodynamics, a branch of physics, concerns itself with the effects of changes in temperature on physical systems . It is believed that metabolic reactions are somehow affected by temperature and generally, the higher the temperature, the faster the metabolic reactions occur. Does temperature affect metabolic reactions? Do metabolic reactions affect development rate? We studied larvae of Vanessa cardui , thePainted-Lady Butterfly, to answer these questions. Vanessa carduiis a well-known colorful butterfly, sometimes known in North America as the Cosmopolitan. It is one of the most widespread of all butterflies, found on every continent except Antarctica. Moreover, it occurs in any temperate zone. This organism metamorphoses from a larva to a butterfly, making development easily observable. Furthermore, its relatively short life cycle makes collecting data more time efficient. Unfortunately, 100% of our treatment group died because of a heating pad malfunction. The two survivors both formed a chrysalis on Day 11. The control group, having grown naturally were larger, and took an average of 14 days to pupate. The P value associated with our t statistic was 0.87-9 , indicating a highly significant difference between treatment and control. Our null hypothesis was rejected. METHODS AND MATERIALS To perform our experiment, we obtained 12 caterpillars for each of a control and experimental group. Then we placed 6.35 grams of caterpillar food in each of 24 cups. We gently brushed one caterpillar into each of the 24 cups and then placed 12 cups into a control bin and the other 12 into an experimental bin. To test one variable, temperature, we placed a heating pad under our experimental bin to keep a temperature of 25oC. Our control group was left at 20oC. To make sure that our temperatures remained constant in both groups, we placed thermometers in each bin. We then measured, in days, the time it took until each caterpillar reached the pupa stage. We used a student’s t-test to analyze our data. TAXONOMIC RANKS • Legend: • C# is the name used to identify each caterpillar in the control group • E# is the name used to identify each caterpillar in the experimental group • D# is the number of days it took for the caterpillar to reach the pupa stage • N/A is used to identify the caterpillars that died before the pupa stage Domain: Eukarya Kingdom: AnimaliaPhylum: ArthropodaClass: InsectaOrder: LepidopteraFamily: NymphalidaeGenus: VanessaSpecies: cardui Hurtled Turtles: Desmond Bellinger Gabriela Huete Keandre Heard Trenton Knight Gabby Ramirez