Collections held in archives, libraries, and museums are priceless testaments to cultural heritage. Unfortunately, paper, wood, leather, and fabrics provide an ideal environment for the growth of many organisms that, silently and covertly, can cause irreversible damage.
Insects, acting insidiously, can destroy entire collections before their presence is even noticed. Understanding the nature of this threat and being able to recognize pests and their feeding patterns is the first step towards effective crop protection.
Who are the enemies of harvesting and how to identify them?
Pests can be divided into groups depending on the material that constitutes their main food.
Wood pests (Xylophages)
This group of insects destroys everything made of wood: furniture, picture frames, sculptures, and even structural elements of buildings.
- Knockers (e.g. house knocker, spotted tick): These are the most common pests of processed wood, preferring cool, moist conditions. Their larvae burrow into the wood, leaving behind characteristic outlet holes with a diameter of 1-2 mmThe spotted woodworm attacks old, often moldy wood, posing a threat to historic structures.
- Hylotrupes bajulus: It attacks dry coniferous wood. Its larvae burrow wide, oval tunnels (up to 7 mm in diameter), filling them with wood flour and excrement. It is particularly dangerous to structures no older than 150-200 years.
- Ambrosia beetles (brown ambrosia beetle): It specializes in starchy hardwoods (e.g., oak). The larvae feed inside, transforming the wood into a fine dust, leading to its complete destruction, often while leaving the thin outer layer intact.
Paper and adhesive pests
Archives and libraries are a true paradise for them. They feed on cellulose, starch, and organic glues used in historical book bindings.
- Stegobium paniceum: One of the most dangerous pests in libraries, responsible for up to 80% of insect damage. Its larvae are omnivorous but are particularly fond of bookbinding glue. They carve characteristic circular channels in book blocks, damaging paper, cardboard, leather, and canvas.
- Lepisma saccharina: It prefers dark and moist environments. It causes superficial, irregular lesions and yellowish discoloration on paper, photographs, and textiles.
- Psocoptera: Their presence is a strong indicator of excessive humidity (above 60%). They feed on microscopic mold fungi, causing minor damage to the paper surface.
Pests of textiles and organic materials
Ethnographic, natural history and textile collections are the target of insects capable of digesting keratin (protein that builds hair, feathers and horns).
- Leatheridae (e.g. black beetle, Smirnov's red beetle): A real nuisance to museums, their larvae feed on wool, silk, furs, leather, carpets, and entomological collections, causing holes and complete destruction of objects.
- Moths (e.g. hair moth): Commonly known clothing pests, they pose an equally serious threat to museum collections. Their larvae create characteristic webs and tunnels on the surfaces of woolen fabrics, furs, and carpets.
How to recognize pest activity?
Most of the damage is caused by larvae feeding within the material, making early detection difficult. Visible signs usually indicate an advanced and long-term problem. Understanding these signals is key to taking quick action.
What should you pay special attention to?
- Outlet holes: This is the most obvious, though often delayed, evidence of pest presence. These are holes made by adult insects that emerge from the material after completing their development cycle. Their shape and size can help identify the culprit: small, round ones (1-2 mm) are typical of knockers, while larger, oval ones (up to 7 mm) indicate a knocker.
- Wood flour (bark flour): Fine dust spilling from holes or accumulating under an infected object is a sure sign of an active infestation. It's a mixture of larval excrement and shredded material (wood, paper).
- Sidewalks and corridors: These are tunnels excavated by larvae within the material, constituting a major source of structural damage. Often invisible from the outside, they can become visible in cracks or fractures. Sometimes, larval activity (especially in the case of the spotted woodworm) can be heard as a quiet scraping or "knocking" sound.
- Molting: As they grow, the larvae shed their cuticles repeatedly. These empty, often transparent "cuticles" can be found near feeding sites, in crevices in furniture, or in fabric folds. They are irrefutable evidence that a new generation of pests is developing within the facility.
- Dead and living insects: The presence of adult insects (e.g., on windowsills or near windows) is a red flag. It indicates that the development cycle has ended and the insects are seeking breeding partners and sites to lay more eggs, which may spread the infestation to other objects.
Modern crop protection: From reaction to prevention
Modern conservation is moving away from the use of toxic pesticides in favor of Integrated Pest Management (IPM). It's a philosophy that emphasizes long-term prevention and risk minimization, treating chemical interventions as a last resort. Its pillars are:
- Prevention: Sealing buildings, keeping them clean and, most importantly, strict climate control (stable temperature and humidity).
- Monitoring: Regular visual inspections and use of traps for early threat detection.
- Intervention: Taking action only after the harmfulness threshold has been exceeded, starting with the least invasive methods.
- Rate: Verification of the effectiveness of the actions taken and improvement of the program.
The overarching principle is primum non nocere – "first, do no harm". A pest control method that destroys pests but also damages the monument is a failure from a conservation perspective.
Choosing the right disinfection method
For years, chemical fumigation was the standard, but today it's a highly problematic method. Toxic gases like ethylene oxide and phosphine not only pose a lethal threat to humans but also react with historic materials, causing irreversible degradation, corrosion of metals, and discoloration of pigments.
The alternative has become freezing, which eliminates the chemical risk but introduces a serious physical hazard. Freezing water increases its volume, which can lead to cracking of wood, crumbling of paper and loosening of paint layers, especially in objects composed of many materials.
In light of these threats, the gold standard in modern conservation is considered anaerobic method (anoxia), which combines 100% effectiveness with complete safety for facilities.
Nitrogen disinfection with OxygenFree from An2Di
The anaerobic method involves replacing the air in a sealed chamber with an inert gas. – nitrogen. In an oxygen-deprived environment (less than 0.3%), all developmental stages of pests, from eggs, through larvae, to adults, – die due to oxygen deprivation. This process is completely safe because nitrogen, which constitutes 78% of the atmosphere, does not enter into any chemical reactions with historic materials.
Ecological nitrogen generator for crop disinfestation OxygenFree An2Di This device was created with the needs of museums, libraries, and archives in mind. It allows for effective protection of resources without the use of risky chemicals.
Effective and safe
The device extracts nitrogen directly from the surrounding air, creating an anaerobic environment. A properly performed pest control process lasts from 21 to 25 days and guarantees the destruction of all development stages of pests without causing any damage to the objects. Disinfection takes place in a special balloon with folii EVOH, która jest odporna na przenikanie tlenu i może być wykorzystywana wielokrotnie.
Environmentally friendly and completely safe
Unlike chemical-based methods, OxygenFree An2Di does not require the use of any toxic substances. Nitrogen, a natural component of air, does not pose a threat to people or the environment. After the process is complete, the gas simply returns to the atmosphere, leaving no harmful residue behind.
Simple and quick process
The entire procedure is easy to implement and requires no outside involvement. It can be performed independently, anywhere, even for a single facility. The complete kit includes all the necessary components to get started immediately:
- Nitrogen generator with intuitive control panel,
- additional tank
- Impulse sealer and EVOH foil for building chambers
- Complete set of valves, pipes and accessories
OxygenFree An2Di All this makes OxygenFree An2Di a practical, ecological and effective solution that enables effective protection of valuable crops – without chemicals, waste and unnecessary complications.