Issues with Tropical Milkweed

Tropical milkweed (Asclepias curassavica) is a non-native species that has become popular for its ease of growth and attractive appearance. However, there are several issues associated with planting tropical milkweed:

 

Parasite Transmission

Tropical milkweed can harbor a protozoan parasite called Ophryocystis elektroscirrha (OE). When monarch butterflies lay eggs on tropical milkweed, the OE can be transmitted to the caterpillars, leading to lower migration success, reduced body mass, and decreased lifespan.

 

Disruption of Migration

In regions where tropical milkweed does not die back in winter, it can disrupt the natural migration patterns of monarch butterflies. Monarchs may breed year-round instead of migrating, which can negatively impact their population dynamics.

 

Toxicity Under Climate Change

Emerging research suggests that tropical milkweed may become toxic to monarch caterpillars under warmer temperatures associated with climate change. Higher temperatures can increase the concentration of cardenolides, which are toxic compounds in milkweed.

 

Ecological Impact

Tropical milkweed’s fast growth and prolific re-seeding can lead to large monocultures that replace native plants and disrupt local ecosystems. This can have negative effects on both wildlife and human communities that rely on native plant species.

 

Recommendations

To mitigate these issues, it is recommended to:

• Replace tropical milkweed with native milkweed species that are better suited to local ecosystems and do not pose the same risks.

 

Common Names

Tropical milkweed is also known by several other common names, including:

• Bloodflower
• Mexican Butterfly Weed
• Mexican Milkweed
• Sunset Flower
• Scarlet Milkweed
• Silkweed

 

By following these guidelines and understanding the common names, you can help support the health and migration of monarch butterflies while preserving local ecosystems.