Cucurbita pepo is a cultivated plant of the genus Cucurbita. It yields varieties of winter squash and pumpkin, but the most widespread varieties belong to the subspecies Cucurbita pepo subsp. pepo, called summer squash. It has been domesticated in the Americas for thousands of years. Some authors maintain that C. pepo is derived from C. texana, while others suggest that C. texana is merely feral C. pepo. They have a wide variety of uses, especially as a food source and for medical conditions. C. pepo seems more closely related to C. fraterna, though disagreements exist about the exact nature of that connection, too. It is a host species for the melonworm moth, the squash vine borer, and the pickleworm. They are also the preferred pollen for squash bees. C. pepo is one of the oldest, if not the oldest domesticated species. The oldest known locations are in southern Mexico in Oaxaca 8,000–10,000 years ago and Ocampo, Tamaulipas, Mexico about 7,000 years ago. Before the arrival of Europeans C. pepo, along with C. moschata, had been carried over all parts of North America where they could be grown. The ancient territory of C. pepo extended north into Texas and up the Greater Mississippi River Valley into Illinois and east to Florida, and possibly even to Maine. It is one of several plants cultivated in prehistoric North America as part of the Eastern Agricultural Complex. It is known to have appeared in Missouri at least 4,000 years ago. Some varieties grow in arid regions and some in moist regions. Many of these peoples, particularly in the west, still grow a diversity of hardy squashes and pumpkins not to be found in commercial markets. Still, neither C. pepo nor C. moschata had been carried into South America as had beans, which originated in the same general region. Debates about the origin of C. pepo have been going on since at least 1857. Recent biosystematic investigations indicate two distinct domestication events in two different areas: one in Mexico and one in the eastern United States, with Cucurbita pepo subsp.