In studying evolutionary adaptations of insects, one interesting example is the corn borer Ostrinia nubilalis, or a worm that makes a living off of human grown corn. During the growing season, the worm spends its time towards the top of the stalk while feeding on the corn. However, when the corn is ready to be havested, the worm makes its way down the stalk before spinning its cocoon for the winter. The depth that it descends down the stalk often exactly parallels the height at which the stalk is cut by the farmer for harvest. Its close neighbor, whom scientists recently thought were the same species lives on non harvested crops and displays almost all of the same habits except for the descent down the stalk. Scientists speculate that the evolutionary pressures of harvesting have perpetuated a population that descended farther and farther down the stalk of corn.