Nocturnal Insect Survey — June Collection

The night was warm and humid, with a barometric pressure of 29.92 inHg and a waxing crescent moon providing minimal light. Conditions were ideal for nocturnal insect activity.

Method

I set up a UV light trap at 20:30, approximately 50 meters from the nearest trail, in a mixed cove hardwood forest dominated by tulip poplar (Liriodendron tulipifera) and eastern hemlock (Tsuga canadensis). The sheet was positioned facing south, with a slight clearing to maximize visibility.

Collection Log

Lepidoptera

The moth activity was exceptional, likely due to the recent rains and high humidity.

1. Luna moth (Actias luna) — 1 male. Arrived at 21:15. Wingspan approximately 10 cm. The pale green coloration was striking against the white sheet. It remained for nearly an hour before disappearing into the canopy.

2. Rosy maple moth (Dryocampa rubicunda) — 3 individuals. These small, pink-and-yellow moths arrived in quick succession around 21:30. They were skittish and difficult to photograph.

3. Underwing moth (Catocala sp.) — 2 individuals. Likely Catocala ultronia. The bright red hindwings were only visible in flight; at rest, the cryptically patterned forewings made them nearly invisible against tree bark.

4. Imperial moth (Eacles imperialis) — 1 female. A magnificent specimen, arriving at 22:40. The yellow and purple-brown patterning was particularly vivid.

Coleoptera

Beetle activity was moderate, with several interesting species:

• Eastern eyed click beetle (Alaus oculatus) — 1 specimen. The large false eyespots on the pronotum are remarkably convincing.
• Firefly (Photinus pyralis) — Numerous. Observed flashing patterns but did not collect.
• Bess beetle (Odontotaenius disjunctus) — 2 specimens. Found crawling on the sheet rather than flying to it.

Observations

The diversity of moths in this single location, on a single night, is a powerful reminder of the unseen abundance that surrounds us. We walk through a world teeming with life that only reveals itself after dark.

I noted that the peak activity period was between 21:30 and 23:00, with numbers declining sharply after midnight. Temperature dropped from 24°C at 20:30 to 19°C by 01:00, which likely contributed to the decline.

Specimens Collected

• Actias luna — photographed and released
• Dryocampa rubicunda — 1 specimen collected for reference
• Eacles imperialis — photographed and released
• Alaus oculatus — collected

Notes for Next Survey

• Bring a larger light source — the 15W UV bulb was adequate but a 40W would likely attract more specimens
• Set up earlier in the evening (dusk is when many species become active)
• Bring better macro photography equipment
• Consider using a bait trap in addition to the light trap

Survey concluded at 01:30. Total species observed: 14 (estimated).