Pinning a dead spider is a meticulous process that preserves the specimen for scientific study, identification, or display. It requires careful handling, the right tools, and attention to detail to ensure the arachnid maintains its natural posture and remains intact over time.
Step-by-Step Guide to Pinning a Dead Spider
Proper preparation and technique are crucial for creating a durable and aesthetically pleasing specimen.
1. Preparation and Relaxation of the Specimen
The initial condition of the spider dictates the first steps.
- For Freshly Deceased Spiders: If the spider has recently died and is still flexible, handle it gently with fine-tipped forceps. Carefully pick out the specimen and place it on a paper towel for 10 to 20 minutes. This short period allows excess moisture to dissipate. When the spider is almost dry but still soft and pliable, it is ready to be pinned. This ensures the legs can be posed without breakage.
- For Dried and Brittle Spiders: If the spider is already dry and stiff, it must be relaxed before pinning. Attempting to pin a brittle specimen will likely result in damage.
- Relaxing Chamber: Create a relaxing chamber by placing a damp (not wet) paper towel or cotton in a sealed container (e.g., a plastic food container or jar). Ensure no water directly touches the spider.
- Rehydration: Place the dried spider inside the chamber. The humidity will gradually rehydrate the tissues, making the specimen pliable again. This process can take anywhere from 1 to 3 days, depending on the spider's size and how dry it is. Check its flexibility periodically.
2. Selecting the Right Pin
Using appropriate pins is fundamental for long-term preservation.
- Insect Pins: Always use specialized entomological pins made from stainless steel, which prevents rust and corrosion. These pins come in various sizes, typically numbered #00 to #7.
- Size Selection: For most spiders, a #2 or #3 pin is suitable. Larger, heavier spiders may require a #4 pin to provide adequate support, while very small spiders might need a #0 or #1 pin. The pin should be long enough to pass through the spider and still leave enough room for a label below.
3. Strategic Pin Placement
The placement of the pin is critical for stability and avoiding vital internal structures.
- Target Area: Unlike insects where the pin often goes through the thorax, spiders are pinned through the prosoma (cephalothorax). Insert the pin slightly to the right of the midline, towards the posterior (rear) end of the prosoma.
- Angle and Depth: Push the pin straight down through the prosoma until about one-third to one-half of the pin remains above the spider. Ensure the pin passes cleanly through and anchors the spider firmly. This placement helps avoid damaging sensitive organs and provides good support for the body.
4. Posing the Spider
Once pinned, the spider's legs need to be carefully arranged.
- Spreading Board/Pinning Block: Place the pinned spider on a soft surface like a foam pinning block or a specialized spreading board. The block should be firm enough to hold additional pins.
- Arranging Legs: Using fine-tipped forceps and additional small pins, gently spread the spider's legs into a natural or symmetrical position. You can use thin strips of paper or card stock to hold the legs down if needed, securing them with additional pins.
- Natural Posture: Aim for a posture that allows all leg segments to be visible, slightly spread, resembling how the spider might appear when active.
- Drying: Allow the spider to dry completely in this posed position. This can take 1 to 3 weeks, depending on the spider's size and ambient humidity. The specimen must be completely dry and rigid before handling or moving.
5. Labeling Your Specimen
Accurate and complete labeling is essential for scientific value.
- Label Content: Once the spider is dry, create a small, neatly printed label with all relevant collection data. This typically includes:
- Location (country, state, county, specific locality)
- Date of collection
- Collector's name
- Habitat notes (optional, but valuable)
- Species name (if identified)
- Placement: Attach the label to the main pin, positioned beneath the spider, about two-thirds of the way down the pin, leaving room for additional labels (e.g., identification labels) if necessary.
Essential Tools for Spider Pinning
| Tool | Purpose | Key Tip |
|---|---|---|
| Entomological Pins | To firmly hold the spider; rust-proof. | Use stainless steel pins; choose size appropriate for spider's body. |
| Fine-Tipped Forceps | For delicate handling of specimens and small pins. | Opt for high-quality, pointed forceps for precision. |
| Foam Pinning Block | A soft, stable surface to insert pins and pose specimens. | Ensure it's dense enough to hold pins securely without crumbling. |
| Relaxing Chamber | To rehydrate dried, brittle spiders. | Use a sealed container with a damp (not wet) substrate. |
| Paper Towel | For initial drying of fresh specimens. | Absorbs excess moisture, preventing mold. |
| Card Stock/Paper | To hold legs in place during the drying process. | Cut into narrow strips and secure with additional pins. |
Tips for a Successful Display
- Handle with Care: Always handle spiders by their main pin or with forceps to avoid damaging delicate appendages.
- Well-Lit Workspace: Work in a brightly lit area, ideally with a magnifier, to see fine details.
- Practice: If you are new to pinning, practice on less valuable or more common specimens first.
- Patience: Rushing the process, especially during relaxation and drying, can lead to irreversible damage.
Common Mistakes to Avoid
- Pinning through the Abdomen: The abdomen of a spider is soft and prone to shrinking or collapsing when dried, making it an unsuitable place for pinning.
- Using Household Pins: Common sewing pins or office pins will rust over time, staining and destroying your specimen. Always use stainless steel entomological pins.
- Not Relaxing Brittle Specimens: Attempting to pose a dry, brittle spider without rehydrating it first will almost certainly result in broken legs or appendages.
- Improper Drying: If the spider is not completely dry before being moved or stored, it can become susceptible to mold or pest infestation.
