The distribution of Malacosoma americanum among Prunus serotina trees.

Abstract

This paper is to explain the exponential growth of one pest species and to provide insight as to how their population changes among distribution factors. The Malacosoma americanum (Eastern tent caterpillar), lives among its host species, Prunus serotina, where it is able to completely defoliate this tree population in years when exponential growth is extremely high. I questions I seek to answer regard population growth, the relationship between host species and the number of egg masses or tents, the relationship female tent caterpillars have about oviposition preference among the host species, and the effect radiant intensity among the orientation of the tents and egg masses. A total of 40 Prunus serotina trees were selected from my 50 x 50 meter plot located along the north side of Riggsville road, about 2 miles from the intersection of Riggsville Rd. and US-31 in Pellston, Michigan. Twenty-two of these trees contained M. americanum tents. There was a statistically significant relationship between diameter ground height (DGH) and the number of egg masses, and a general trend between tree height and egg masses, suggesting that as the tree size increases, the number of egg masses increases. Actually 92% of large trees contained either tents or egg masses, while 37% of small trees had tents or egg masses. However, there was no statistically significant relationship between number of tents and DGH or height. In this study, egg masses did not have a statistically significant relationship to degree orientation to either the north or south. I found the tent caterpillar population to be slightly decreasing, and from the Poisson distribution, Prunus serotina trees with tents were randomly dispersed, while trees without tents or egg masses were clumped.