Aphids' presence deters monarch butterflies from tropical milkweed, study reveals
A study from the University of Florida reveals that aphids infesting tropical milkweed, a common plant used to attract and support monarch butterflies, negatively impact the butterflies' reproduction and development. Aphid-infested plants receive fewer eggs from monarch butterflies, and the caterpillars that do hatch are slower to mature. The study suggests that aphid outbreaks compromise the availability of milkweed, a crucial resource for monarch butterflies. Native milkweed species with lower cardenolide levels, such as swamp milkweed, are recommended for home gardeners in the southern U.S. who want to conserve monarch butterflies. Insecticidal soap is an effective method to control aphids on tropical milkweed, but alternative pest management options that are safe for monarch butterflies are being explored.