Spiders

Resource Tags:

Spiders 
Insects, Spiders, & More 

About the Resource:

Spiders are diverse arachnids known for their web-building and predatory behavior. Most spiders are beneficial, controlling insect populations, but some can be a concern due to their venom or for their presence in homes.

Identification

Images of Spiders: https://entomology.unl.edu/images/spiders/spiders1

  1. General Characteristics
    • Body Structure: Spiders have two main body parts: the cephalothorax (combined head and thorax) and the abdomen. They also have eight legs, unlike insects, which have six.
    • Eyes: Most spiders have multiple eyes, with arrangements varying by species. Spiders can have eight, six, or zero eyes. Arrangement of the eyes is important for proper identification. 
  2. Common Spiders
    • Orb-Weaver Spiders: Known for their large, circular webs, these spiders are common in gardens. Examples include the garden spider (Araneidae) and the golden orb-weaver (Nephila).
    • Jumping Spiders: Small, agile spiders with excellent vision. They do not spin webs but actively hunt for prey. An example includes the bold jumper.
    • Wolf Spiders: Ground-dwelling spiders that do not spin webs but actively hunt and chase their prey. They are often hairy and robust.
    • Brown Recluse: A venomous spider known for its violin-shaped marking on its cephalothorax. It prefers dark, undisturbed areas.
    • Black Widow: Recognizable by its glossy black body and red hourglass marking on the underside of the abdomen. It is venomous and can be dangerous.
  3. Spider Webs
    • Orb Webs: Circular and spiral-shaped, these are common in gardens and outdoor areas.
    • Sheet Webs: Flat, horizontal webs often found in grass or low vegetation.
    • Funnel Webs: Funnel-shaped webs with a tubular retreat where the spider hides.
    • Cobwebs: Irregular, tangled webs typically found in corners and undisturbed areas inside homes.

Spiders and Their Role

  1. Beneficial Spiders
    • Pest Control: Spiders prey on various insects, including mosquitoes, flies, and pests, reducing the need for chemical pest control.
    • Ecosystem Balance: They contribute to the balance of ecosystems by controlling insect populations and serving as prey for other wildlife.
  2. Venomous Spiders
    • Health Risks: While most spider bites are harmless, some, like the Brown Recluse and Black Widow, can cause health issues. Symptoms can range from mild irritation to severe reactions or systemic effects.

Management and Control

  1. Prevention
    • Keep Clean: Regular cleaning and decluttering reduce spider hiding places and prey.
    • Seal Entry Points: Seal cracks, gaps, and entry points in windows, doors, and foundations to prevent spiders from entering homes.
    • Outdoor Maintenance: Keep outdoor areas well-maintained by removing debris, trimming vegetation, and keeping grass short.
  2. Physical Controls
    • Web Removal: Regularly remove spider webs from indoor and outdoor areas using a broom or vacuum cleaner.
    • Traps: Use sticky traps to monitor and capture spiders, especially in areas where they are commonly seen.
  3. Chemical Controls
    • Insecticides: Insecticidal sprays or dusts can be used to control spider populations, especially around entry points and known spider habitats. Always follow label instructions and safety precautions.
    • Residual Sprays: Apply residual insecticides around the perimeter of buildings to create a barrier against spiders. These do not work well for spiders that remain in their webs.
  4. Natural and Non-Toxic Controls
    • Essential Oils: Some essential oils, such as peppermint, eucalyptus, or citrus, are believed to repel spiders. Mix with water and spray around entry points and spider-prone areas.
    • Diatomaceous Earth: This natural powder can be sprinkled in areas where spiders are active. It works by damaging the exoskeleton of insects and spiders, leading to dehydration.
  5. Professional Pest Control
    • Infestation: If you have a significant spider infestation or encounter venomous spiders, consult a pest control professional for effective treatment and management.

When to Seek Professional Help

  • Venomous Spiders: If you suspect the presence of venomous spiders, or if someone is bitten and shows severe symptoms, seek medical attention immediately. When possible, bring the spider that bit you to your healthcare professional. 
  • Large Infestations: For extensive spider problems or recurring infestations, a professional pest control service can provide a thorough inspection and treatment plan.