# Chemists find Colletes inaequalis bee nest lining is 73% polyester and breaks down in soil

- Published: 2026-11-04 23:55 UTC
- Section: Machines & Making › Materials science
- Tags: bee nest lining, biodegradable polyester, Colletes inaequalis, plasterer bee, macrolactones, crystalline polymer, polyethylene-like film, polymer degradation in soil, natural plastic
- URL: https://realtech.media/news/rt-d6c0cc653783a2666dcb29a4_chemists_find_colletes/

**Nest lining of Colletes inaequalis bees from one nesting site lost part of its polyester in soil over months; the degradation mechanism is still unknown.**

![Chemists find Colletes inaequalis bee nest lining is 73% polyester and breaks down in soil](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/9f88d2a76b494c5a.jpg)
*Наука.ua*

Chemists have found that the material lining the nests of the plasterer bee Colletes inaequalis consists of polyester and silk. The study was published in Proceedings of the National Academy of Sciences, as reported by Наука.ua. Despite its high crystallinity, which usually hinders the breakdown of plastics, the bee polyester degraded quickly in soil. [1]

## Composition of the nest lining

Females of C. inaequalis dig underground nests and coat the walls with a thin, transparent film that outwardly resembles polyethylene. The film protects the offspring and pollen stores from moisture and fungi. [1] The bees secrete a mixture of cyclic molecules, macrolactones, from a special gland, and these polymerize on the nest walls to form the film. The bees can build nests in the same place for decades, yet, unlike synthetic polyethylenes and polyesters, their polymer does not accumulate in soil.

The researchers collected nest samples from one settlement right after construction and again after four, seven and eleven months. Physicochemical analysis showed that fresh lining is about 73 percent polyester and 27 percent silk fibers. [1] The polyester did not dissolve even in heated organic solvents, which indicates that its molecular chains are joined by cross-links into a three-dimensional network rather than lying side by side. About 60 percent of the polymer is in a crystalline state, and its structure resembles polyethylene.

## Degradation in soil

After four months in soil, the polyester share of the film fell from 73 to 40 percent. At seven months cracks appeared on the lining, and at eleven months it had become brittle. [1]

The mechanism of the breakdown has not yet been established. One possibility is that some of the ester bonds between polymer units lie outside the crystalline regions, making them more accessible to chemical reactions. Another version involves enzymes produced either by bacteria that settle in the nests or by the bees themselves.

According to the researchers, further study of the bee polymer could help in creating plastics that combine the properties of polyethylene with the ability to degrade under natural conditions.

## Sources

1. [Наука.ua](https://nauka.ua/news/plivka-z-bdzholinih-gnizd-viyavilasya-biorozkladnim-plastikom)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-d6c0cc653783a2666dcb29a4_chemists_find_colletes/