Global climate change and phenological shifts

Abstract

The effect of global climate change on spring phenology was studied by examining the close interactions between eastern tent caterpillars (Malacosoma americanum) and black cherry trees (Prunus serotina). Eastern tent caterpillars are one example of insect herbivore specialists (herbivores that feed on 3 or fewer plant families) and will most likely be greatly affected by global climate change. We investigated how caterpillar growth and consumption could be affected if global climate change speeds up leaf budburst so that the caterpillars are forced to eat older, less nutritious leaves. We simulated asynchrony between caterpillar egg hatch and leaf budburst by stunting the caterpillars’ growth and placing them in an environmental chamber at 15C for varying lengths of time (six days, four days and two days). We compared the consumption and growth of all three trials to our control group, which was still in sync with the leaves. We discovered that although two days of asynchrony might not be enough to greatly affect the caterpillars’ growth, four days of asynchrony did impact caterpillar growth. Six days of developmental delay did not significantly affect caterpillar growth. This could be attributed to varying abilities to acclimate to cooler temperatures. Additionally, six and four days of asynchrony did not create a significant difference in caterpillar consumption, however there was a difference with only two days of developmental delay. This may be a result of different levels of efficiency in digestion.