False Widow Spider

Where it lives

Window frames, garage corners, under sills, in garden furniture, sheds, wall crevices and around external lighting where insects gather.

Signs

• Dark bulbous spiders in tangled webs in corners and window reveals
• Webs concentrated near external lights and vents
• Increased sightings in autumn as males wander looking for mates
• Egg sacs suspended in the web

Risks

• Bite can cause localised pain and swelling; systemic effects are uncommon
• Webs and debris are unsightly on façades and balconies
• Considerable anxiety because of confusion with the black widow

Prevention

• Brush down webs from window reveals, balconies and eaves regularly
• Reduce external lighting or switch to warm-toned lamps that attract fewer insects
• Fit fly screens and seal gaps around frames
• Keep garden furniture and stored items clear of walls
• Wear gloves when reaching into sheds and undisturbed storage

Treatment

A residual perimeter treatment applied to window reveals, eaves, doorways and balcony soffits, combined with physical web removal and advice on reducing the insect prey that attracts them. Two treatments a year, in spring and autumn, keep façades clear.