Pan trap

A pan trap with a number of insects having been attracted to it

A pan trap is a type of insect trap used to sample the abundance and diversity of insects, primarily used to capture small Hymenoptera. ^[1] Pan traps are typically constructed with a bowl with shallow sides filled with water and soap or a preservative and killing agent. Yellow is the most commonly used color, ^[2] but other colors including blue, white, and red are used to target different insect species. ^[3]

Trap construction

A pan trap consists of a shallow bowl, typically made of colored plastic, filled with water and a surfactant such as dishwashing liquid, salt, propylene glycol, antifreeze, or combinations of other preservatives and killing agents. The surfactant lowers the surface tension of the water, causing the insect to sink and eventually drown ^[4] . Salt and propylene glycol are sometimes included as preservatives or to reduce evaporative water loss. Even with these additions, enough liquid needs to be added to prevent the trap from drying out, but too much liquid will cause the trap to overflow if it rains. Small traps dry out quicker, so longer surveys tend to use traps with a larger volume ^[5] . Traps may be attached to a stake ^[6] or weighed down with a rock to prevent movement by the wind or animals ^[7] Some traps have been mounted on trees to sample the communities of parasitoid wasps of the invasive beetle, Emerald ash borer. ^[8]

Colors

The color of pan traps attracts diverse groups of flying insects. Some pollinators confuse the traps with natural flowers, causing the capture of flying pollinator species, including bees. ^[9] Some studies have suggested that bee species are more attracted and likely to be captured in blue or white pans compared to yellow pans. ^{[3] [10]} However, yellow and white pan traps consistently collect the largest number of species. ^{[11] [12]}

References

1. Nancy D. Epsky; Wendell L. Morrill; Richard W. Mankin (2008). "Traps for Capturing Insects" (PDF). In Capinera, John L. (ed.). Encyclopedia of Entomology. Dordrecht: Springer. pp. 3887–3901. ISBN   978-1-4020-6242-1.
2. Southwood, Richard, Sir (1988). Ecological Methods: With Particular Reference to the Study of Insect Populations (2 ed.). Dordrecht: Springer Netherlands. ISBN   978-94-009-1225-0.
3. Buffington, Matthew L.; Garretson, Alexis; Kula, Robert R.; Gates, Michael W.; Carpenter, Ryan; Smith, David R.; Kula, Abigail A. R. (2021). "Pan trap color preference across Hymenoptera in a forest clearing" . Entomologia Experimentalis et Applicata. 169 (3): 298–311. doi:10.1111/eea.13008. ISSN   1570-7458. S2CID   231929465.
4. Patrick, Brian (2016). Invertebrates: light trapping (PDF) (Report). Wellington, New Zealand: Department of Conservation. Retrieved 12/10/2025.{{cite report}}: Check date values in: |access-date= (help)
5. Krahner, André; Dietzsch, Anke C.; Jütte, Tobias; Pistorius, Jens; Everaars, Jeroen (2024). "Standardising bee sampling: A systematic review of pan trapping and associated floral surveys". Ecology and Evolution. 14 (3): e11157. doi:10.1002/ece3.11157. ISSN   2045-7758. PMC   10944983 . PMID   38500849.
6. Chinga, J.; Murúa, M.; Barahona-Segovia, R. M.; Gelcich, S. (2024-01-01). "Pan traps: An effective tool for monitoring phenological changes in insect floral visitors and their relationship with floral resources in a coastal Mediterranean forest". Ecological Indicators. 158: 111336. doi:10.1016/j.ecolind.2023.111336. ISSN   1470-160X.
7. Bulbert, Matthew; Gollan, John; Donnelly, Andrew; Wilkie, Lance (2007). Invertebrate Collection Manual (PDF) (Report). Sydney, Australia: Australian Museum. Retrieved 12/10/2025.{{cite report}}: Check date values in: |access-date= (help)
8. Bauer, Leah; Hansen, Jason; Gould, Juli (2014). "Yellow Pan Traps: A Simple Method for Trapping Parasitoids Released for Biological Control of the Emerald Ash Borer" (PDF).{{cite journal}}: Cite journal requires |journal= (help)
9. Westerberg, Lars; Berglund, Hilda‐Linn; Jonason, Dennis; Milberg, Per (15 March 2021). "Color pan traps often catch less when there are more flowers around". Ecology and Evolution. 11 (9): 3830–3840. doi:10.1002/ece3.7252. PMC   8093746 . PMID   33976778.
10. Moreira, Eduardo Freitas; Santos, Rafaela Lorena da Silva; Penna, Uiré Lopes; Angel-Coca, Catalina; de Oliveira, Favízia Freitas; Viana, Blandina Felipe (20 July 2016). "Are pan traps colors complementary to sample community of potential pollinator insects?". Journal of Insect Conservation. 20 (4): 583–596. doi:10.1007/s10841-016-9890-x. S2CID   16596068.
11. Vrdoljak, Sven M.; Samways, Michael J. (1 June 2012). "Optimising coloured pan traps to survey flower visiting insects". Journal of Insect Conservation. 16 (3): 345–354. doi:10.1007/s10841-011-9420-9. S2CID   16104513.
12. Shimoda, Masami; Honda, Ken-ichiro (November 2013). "Insect reactions to light and its applications to pest management". Applied Entomology and Zoology. 48 (4): 413–421. doi: 10.1007/s13355-013-0219-x . S2CID   15295724.