August EcoQuest Challenge

AUGUST APHIDS, MONARCHS, AND MILKWEEDS

Although Milkweeds (Asclepias) have classically been associated with the valuable and endangered Monarch Butterfly (Danaus plexippus), this genus is an actor in a complex community of organisms. They provide habitat and act as a food source for many other species found in New York City. The Oleander Aphid (Aphis nerii) is a non-native aphid that feeds on the sap of milkweed plants and whose population distribution is increasing worldwide. They can now be found in every state in the US including Hawaii. Although they share a host plant, their effects on monarch success is unknown. Some studies suggest they increase the success of monarchs by acting as preferential prey for predators that would normally feed on monarch eggs. Other studies suggest the presence of A. nerii may indirectly increase parasitism on monarchs. Help us understand the connection between the Oleander Aphid and Monarchs by documenting their presence on Milkweeds! You can browse past observations of Milkweeds, Monarchs, and Oleander Aphids here