The collection process of arachnids involves various techniques depending on the specific species and habitat. Here are the main methods used to collect arachnids effectively:
1. Hand Collection
• Method: Directly picking up arachnids using forceps, brushes, or even gloved hands.
• Target Group: Large and easily visible arachnids like spiders and scorpions.
• Best Time: Usually done during daylight for diurnal species and at night using a flashlight for nocturnal species.
• Precautions: Handle with care to avoid bites or stings, especially with venomous species.
2. Pitfall Traps
• Method: Small containers are buried at ground level and partially filled with a preservative solution like ethanol or soapy water. The traps can also have a funnel to prevent escape.
• Target Group: Ground-dwelling arachnids, including spiders and scorpions.
• Best Time: Left in place for a few days to a week to catch active ground-foraging species.
• Advantages: Effective for capturing a wide range of species without constant monitoring.
3. Beating and Sweeping
• Method: Using a stick or pole to tap or beat branches and foliage over a beating sheet or tray. For sweeping, a sweep net is used to pass through low vegetation or grass.
• Target Group: Arachnids that live in vegetation, such as orb-weaver spiders.
• Best Time: Effective during the day when these arachnids are active or resting on plants.
• Advantages: Suitable for capturing species that are otherwise difficult to spot in dense vegetation.
4. Leaf Litter Sampling
• Method: Collecting samples of leaf litter or soil and using a Berlese funnel (or Tullgren funnel) to extract small arachnids. The funnel uses heat or light to drive the animals downward into a container.
• Target Group: Small arachnids like mites, pseudoscorpions, and some small spiders.
• Advantages: Very effective for collecting tiny species that are hard to see with the naked eye.
5. Light Trapping
• Method: Using artificial light sources like UV lamps or white lights to attract nocturnal arachnids.
• Target Group: Nocturnal species, particularly spiders and scorpions that are active during the night.
• Best Time: Most effective after sunset, when nocturnal arachnids are actively hunting or moving.
• Precautions: Handle with care to avoid disturbing or harming the collected specimens.
6. Rock and Log Flipping
• Method: Carefully lifting rocks, logs, or other debris to reveal hidden arachnids. After examination, it’s essential to return the objects to their original positions to minimize habitat disturbance.
• Target Group: Species like scorpions, whip spiders, and some ground-dwelling spiders.
• Best Time: Often more successful in the early morning or late afternoon when temperatures are moderate.
7. Aerial Nets
• Method: Swinging a lightweight net through the air to catch jumping spiders or other agile species that move through the vegetation.
• Target Group: Spider species that actively move through the air or vegetation.
• Advantages: This method works well in areas with tall grasses or dense foliage.
Important Considerations for Arachnid Collection
• Documentation: Record the location, date, time, habitat type, and collection method for each specimen to provide context for future studies.
• Preservation: Place the collected specimens in vials with 70-80% ethanol immediately after collection to preserve their morphology.
• Handling Precautions: Wear gloves and handle arachnids with care, especially if venomous species are involved, to avoid bites or stings.
• Ethical Considerations: Always minimize the disturbance to the natural habitat and ensure sustainable collection practices to protect local biodiversity.
This collection process helps to ensure that the specimens remain in good condition for scientific study, allowing for accurate identification and research on their ecological roles and behavior.