The conservation and restoration of insect specimens is the process of caring for and preserving insects that are part of a collection. Conservation steps start when the insects are collected and continue during preparation, storage, examination, documentation, research, and treatment if restoration is needed.

Collection

Insect collecting can be done in many ways depending on the type of insect and the environment where they live. Both hobbyists and scientists have developed special methods to collect insects with less harm to the specimens. Using proper techniques helps preserve insects from the start by reducing possible damage. It is important to handle insects carefully to protect their features, such as wings, legs, and antennae, which are important for the purpose of the collection. Special tools such as nets, traps, and other methods are used because insects can break easily. A kill jar is often used to quickly stop an insect from moving before it can hurt itself.

Preparation

Preparing insect specimens is usually the first step in their preservation. They must be carefully prepared using the right methods based on their size, body structure, and any delicate parts to prevent them from breaking before they are used for study, research, or display. Some are preserved using a dry method, while others use liquid. The chosen method helps keep important features needed for identification and keeps the insect looking as close to its living form as possible.

Pinning is a dry method used to preserve and display insect collections. It requires special tools and is mainly used for insects with hard bodies, medium to large size, and those that need to be studied easily while keeping their color. Flies and butterflies, which have some soft parts, are best preserved by pinning because using fluid can cause their hairs or scales to clump or fall off. Very small insects may be pinned using thin pins to avoid breaking them. Insects are pinned on foam blocks or special pinning blocks that support their limbs while drying. After drying, they are moved to protected display cases, where they become more brittle. The pin is usually placed through the thorax, just to the right of the middle, to keep one side visible in case of damage. Exceptions include butterflies, dragonflies, and damselflies, which are pinned through the center of the thorax. Enough pin length must remain above and below the specimen to allow for labeling and handling.

Carding is used for very small specimens where pinning would cause too much damage. A triangular piece of acid-free card is cut to protect the specimen. A pin is then inserted through the wide end of the card for mounting. A glue that can be removed with solvents is used to attach the right side of the insect’s thorax to the card’s opposite side. The card may be bent to position the specimen as it would normally be when pinned.

A wet specimen is preserved in a liquid, usually 70% alcohol. This method is used for soft-bodied insects, such as caterpillars, larvae, and spiders, because their soft bodies need to stay flexible to avoid shrinking. This helps keep their identifying features as close to their living form as possible. Hard-bodied insects may also be temporarily stored in alcohol before being pinned.

Very small insects are sometimes kept as slides in insect collections.

Core aspects of conservation

The American Institute for Conservation (AIC) explains in their Code of Ethics that conservation includes several areas: preventive conservation, examination, documentation, treatment, research, and education. These same areas apply to the conservation and restoration of insect specimens.

Insect collections can face many types of damage, such as fading colors from too much light, mold from incorrect humidity or temperature, and pests that eat dried insects. Many of these problems can be avoided with proper preventive conservation.

Keeping insect specimens in a clean storage environment is important. Sometimes, the specimens themselves need cleaning. Very fragile and dry insect specimens are cleaned carefully and step by step. The conservator chooses the best method based on the type of insect and how strong it is. Tools used may include soft watercolor brushes to gently dust specimens, a stereo microscope for tiny specimens, warm water or alcohol baths with or without an ultrasonic cleaner, and lens blowers to remove dust or dry specimens after cleaning.

To protect insect specimens from pests and dust, they are often stored in sealed boxes or cabinets. Sealed storage also helps control humidity and temperature changes. Wet specimens are kept in separate jars or vials inside a secure cabinet, tray, or shelf. Fluid levels in these containers are checked regularly to ensure specimens remain fully submerged. A well-sealed jar or vial prevents too much liquid from evaporating.

Proper handling of insect specimens helps avoid breaking legs, antennae, or other body parts. Curved forceps may be used to handle specimens more precisely and reduce the chance of damage. The handler picks up the specimen by its pin, which is placed with enough space below the specimen to insert it into a pinning block and enough space above to grip without touching the specimen.

Integrated pest management (IPM) is a modern method used in museums to control pests. IPM starts with regular cleaning and checking collections for signs of pests, such as droppings or damaged specimens. Some pests, like carpet beetles and flour beetles, eat dried insects. If an infestation occurs, treatments like freezing or using inert gases to remove oxygen may be used. In extreme cases, safe chemical fumigation might be necessary.

The condition of an insect collection is checked regularly, and the results are recorded. The conservator examines specimens closely, noting any damage or changes. Tools used during this process may include a bright light, magnifying glass, and handling tools that allow the conservator to pick up a specimen without touching it. These observations help decide if treatment is needed. The conservator knows what types of damage to look for in insect specimens.

• Pests: Signs of pests include insect droppings, castings, or damage caused by chewing on specimens.
• Mold: Mold grows when humidity is too high.
• Verdigris: A blue-green, hair-like crystal caused by reactions between copper or brass pins and insect fats.

Documenting insect specimens happens throughout their life. When an insect is captured, the collector records details like the method, location, date, and habitat in field notes. This information is then written on labels and collection records. Every observation or treatment the specimen receives is also recorded. This includes information about killing agents, preservation agents, rehydrating agents, and fumigants. These records help guide future conservation decisions.

Labels on insect specimens must include the collection location, date, and the genus and species. On pinned insects, labels are also pinned with space below the specimen on the same pin. Labels are written with ink that does not fade or wash off and are made from 100% cotton or linen paper to prevent yellowing or brittleness over time.

With better digital photography and online resources, many natural history museums now use digitization to document insect specimens. This allows high-quality images and information to be shared online. Large databases store vast amounts of information, helping researchers.

Scientific illustration is an older method used to document insects. Unlike photographs, illustrations can show details about an insect’s anatomy and behavior through an artist’s work. Careful observation of specimens, combined with technical and artistic skills, creates detailed illustrations that help document each species.

Conservators examine specimens closely after documentation. They record all visible details from detailed inspections. These observations help decide if treatments are needed and inform future conservators and researchers.

Studying insect collections helps scientists learn about ecology, human health, and crops. Well-kept records help researchers determine if differences in specimens are due to damage, treatments, or deterioration. Museum research can lead to new species discoveries and serve as a historical resource.

After examining a collection, the conservator decides what actions to take. Treatments should be reversible or low-risk for the specimen. For example, broken limbs may be glued back on using white glue, which can be removed with warm water. Pest infestations in dried insect collections can be treated by freezing the specimens or sealing them with inert gases to kill pests. Other treatments may include refilling wet specimen jars with alcohol, cleaning dust, or repositioning specimens for display or research. If a specimen needs repositioning, the conservator may use a rehydrating solution in a jar to relax the specimen and move its limbs without breaking them. Methods vary among conservators, but all treatments are carefully documented.

Conservation of insect specimens is done in a way that protects their condition and value.