YELLOW SAC SPIDER INFORMATION & FACTS

The yellow sac spider (Cheiracanthium) is a small spider typically found outdoors. Adult yellow sac spiders are seen between April and November. They do not build webs, rather they build a silken tubes or sacs in locations that offer protection like within plant leaves or under logos. They hideout during the day in their silken sacs, emerging at night to hunt for food.

Yellow sac spiders are around 5 to 8 mm long, with yellow (or beige) colouring, and a banana-yellow coloured abdomen. They have a faded stripe that runs lengthwise. Yellow sac spiders possess 8 dark coloured eyes, arranged in 2 two rows, and 4 pairs of legs. Their first pair of legs is longer than their fourth pair of legs.

A female yellow sac spider can produce up to 5 egg sacs the fall. Each egg sac contains an average of 40 eggs. Baby spiders, or spiderlings, are arrive the following Spring. Interestingly, 30% of adult male yellow sac spiders, post mating, are eaten by their female partner.

These spiders will invade homes and buildings if small insects are present inside, especially in the early fall when their outdoor food supply is dwindling down and becoming difficult to find.  Inside a home or business, they are commonly found at the junction of a wall and ceiling, or even behind shelves and pictures. When disturbed, they drop to the floor and try to hide.

The yellow sac spider can give a sharp, painful bite, and are more inclined to bite humans. These little spiders are very aggressive, more so than the brown recluse spider. Their bites can cause swelling, red patches, itching and numbness were bitten. Others have experienced nausea and sweating.

To prevent a yellow sac spider infestation, prevention is key. Inspect your home or premise and seal cracks and crevices around doors, windows and entry points with good quality caulking. Keeping your home or business clean on a regular basis can help eliminate their food source (little insects).

For large infestations contact a licensed pest control company, like Environmental Pest Control, who has expertise in helping you control and treat a yellow sac spider infestation.