During a recent trip to Costa Rica, I had the opportunity to run a small, improvised mothing setup at a rainforest lodging just south of La Fortuna. While Costa Rica is often described as an insect “firehose,” my experience was a large diversity in species but not an overwhelming number of insects.
The lodging was Junglo Resort and Spa, located in lowland rainforest south of La Fortuna. The site was very remote, with minimal ambient light and substantial separation between guest units which was an important factor when running a light at night. Reliable grid power was available, and the property hosts were amenable to the setup, provided it did not disturb other guests.
The session took place in December 2025, during the drier part of the year for this region, though humidity remained high and evening conditions were warm and stable. True darkness arrived quickly after sunset, with minimal nearby artificial lighting competing with the trap. The lodging did have permanent night lighting that did impact the set-up, but was still vry successful in terms of species.
The setup was intentionally simple and travel-friendly:
- Light: A blacklight LED bulb (exact wavelength unknown) in a standard light socket with simple switch and 6ft cord. This is similar to what you’d find in a household lamp.
- Power: Wall outlet (no battery or generator)
- Sheet: Plain white sheet, hung vertically on a patio chair with a simple clip to hold the sheet in place.
The sheet was secured to allow some airflow but remain taut enough for photography and observation. No secondary lights (mercury vapor, mixed-spectrum bulbs, or actinic tubes) were used.
This was not a permanent trap and was run only for a limited window after dusk, both to minimize disturbance and because rain was common overnight.
Observations: Abundance vs. Diversity
Contrary to expectations some people have of tropical mothing, this was not an exceptionally abundant night. There was no sustained influx of hundreds of individuals, nor the continuous turnover sometimes seen under optimal conditions.
What was immediately apparent, however, was species diversity. Even with modest numbers, the range of forms, sizes, wing shapes, and resting postures exceeded what I typically see during a productive night in the high desert or Front Range of Colorado.
No collecting was done. Documentation was photographic, with the intention of post-session identification. Given the diversity encountered, this is a case where IDs benefit from later review rather than in-the-moment certainty.
Moths
These are some of the moths seen. Species identifications are tentative.
Asturodes fimbriauralis
Southern Milky Argyria Moth Argyria lacteella
Assembly Moth Samea ecclesialis
Plant/leaf hoppers
Aside from moths, many other types of creatures come to the moth light such as this giant plant hopper.
Beetles
Beetles are also a common feature at a moth light, particularly plant-eating beetles.
A beetle probably in the Eumolpinae subfamily
Aspidolea singularis a member of Masked Chafers and Rice Beetles, Tribe Cyclocephalini
Cyclocephala lunulata a member of Masked Chafers and Rice Beetles, Tribe Cyclocephalini
Bugs
Likely Genus Edessa a member of Stink Bugs
Practical Travel Mothing
I had no clue how successful mothing would be on an international trip, but it worked out well! A few logistical notes for anyone considering similar setups while traveling:
- Always get permission from property hosts
- Confirm power availability and outlet locations
- Be mindful of distance to other guests aslight traps can easily disrupt sleep or wildlife experiences
- Keep setups minimal and temporary
- Avoid running lights all night by default, especially consider weather when timing
In a future post, I’ll detail the mothing equipment.
