Tropical Swallowtail Moths in the City: A Silent Signal from Nature

Have you noticed large, eye-catching moths fluttering through city streets and around light posts lately? If so, you're not alone. These moths, identified as Lyssa zampa or the tropical swallowtail moth, have recently made unusual appearances across Metro Manila.

While their wingspan and gentle flight may draw admiration from passersby, scientists and environmental advocates suggest their presence may be more than just a seasonal fluke it could be nature’s quiet call for help.

A Pattern Rooted in Climate and Habitat Change

A 2023 study conducted in Singapore by Jain, Ng, and Sivasothi (Land, Vol. 12, Issue 3) examined the urban emergence of Lyssa zampa. Their research found several potential causes:

• Loss of native host plants

• Extended dry spells due to climate change

• Light pollution in urban areas

The moth’s larvae depend on plants from the Endospermum genus, which have been disappearing due to habitat loss. As these plants vanish from the wild, the moths are forced to search elsewhere sometimes flying directly into the illuminated cities that distract and confuse them.

In short, they're here not because they want to be, but because they have nowhere else to go.

Observations from Metro Manila

Student Sam Brillo recently shared a photo of a Lyssa zampa moth he encountered at PLM (Gusaling Bagatsing) yesterday.

“This moth looked fragile and possibly stressed,” Brillo wrote. “It was beautiful, but it didn’t look like it belonged here. I moved it gently to keep it from being stepped on.”

Another concerned observer, Edriel Lee, shared that he had seen several moths across the city and began to wonder about their sudden visibility. A quick search led him to the same research study, sparking an awareness that what seemed like a lovely encounter was actually a symptom of a much bigger issue.

When Beauty Becomes a Warning

While these moths pose no harm to humans, their presence in cities where they cannot reproduce could lead to population instability. The Singapore study warned that:

• Only strong-flying moths survive the migration to urban areas, leading to reduced genetic variety.

• Their host plants are absent in cities, so reproduction often fails.

• Ongoing exposure to light pollution may alter the species’ behavior permanently.

These factors could eventually reduce the resilience of the Lyssa zampa population and trigger ecological disruptions, especially since moths play roles in pollination and food webs.

Climate Signals Are Getting Clearer

The rise of Lyssa zampa in urban areas isn’t isolated. Experts link it to a pattern of longer dry spells an impact of climate change already being felt in the Philippines and throughout Southeast Asia.

“We are seeing more signs that ecosystems are under stress,” said Jain et al. (2023). “And the creatures most affected are those with the least ability to adapt quickly like insects dependent on specific plants.”

A Call for Awareness

When you next spot a Lyssa zampa, take a moment not just to admire its beauty, but to reflect. These moths are not urban natives. Their presence may be beautiful, but their journey here was not one of choice it was one of survival.

As citizens, we can raise awareness and support conservation efforts that protect habitats and reduce light pollution. We must remember that in nature, even the quietest creatures have something to say if we are willing to listen.

References:

• Jain, A., Ng, S. C., & Sivasothi, N. (2023). Urban emergence of Lyssa zampa moths in Singapore: The role of forests, climate, and light pollution. Land, 12(3), 589. https://doi.org/10.3390/land12030589

• Brillo, S. (2025, June). Facebook post.

• Lee, E. (2025, June). Facebook post.

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