Wolf Spider Control (Lycosa spp.)
Wolf spider control and the control of wolf spiders is difficult, wolf spider are large for a spider: 3/8 to 1 3/8 inches long, with hairy, robust bodies. They’re usually dark brown with paler stripes or markings, but may be yellow with darker stripes or marks. The US and Canada are home to over one hundred species of wolf spiders.
Wolf spiders are hunters and will chase their prey. Often big and hairy and sometimes alarming, they will bite only if harassed. Their bites can cause itching, swelling, and some pain, but are not lethal.
Wolf spiders actively hunt during the night and sometimes during the day. Because wolf spiders feed on a variety of insects, including crop and garden pests, consider letting them be when possible.
Wolf spiders may enter homes or other buildings in search of insect prey, or may be brought in with firewood. They tend to remain at or near floor level, especially along walls under furniture and other objects. Outside they hide under stones, landscape timbers, firewood, under decks in leaf litter, etc.
If you’re finding wolf spiders in your home, sealing up cracks and openings where they’re wandering in is an important first step.
Getting Rid of Jumping Spiders
The first step in controlling spiders (and many other pests) is to seal up places where they can get into your house. Seal cracks on the outside of the house, especially around doors, windows, and where utility lines enter the house. Pay special attention to any cracks or gaps in the foundation. Make sure screens are present on windows and are in good repair. If there are gaps underneath doors, install weatherstripping or sweep strips. Fill any gaps around water pipes under sinks. Use yellow light bulbs for exterior lighting. Use a dehumidifier in basements, cellars, and crawl spaces, or take measures to improve ventilation.
Once you’ve sealed off spider entry points, it’s time to clear out their hiding places within your home. In many houses, storage and clutter are inevitable. Unfortunately, stacks of boxes or debris can serve as spider hiding places, so pull boxes away from the wall. Leave one foot clearance between stacks of boxes. Pull beds one foot from walls, and furniture at least a few inches out. This makes ongoing cleaning and vacuuming easier, which is crucial to controlling spiders and insects. Vacuum under and behind furniture, and along baseboards regularly. Use glue traps (and insecticidal spray) to remove wolf spiders from homes or buildings.
Outside, clean up debris piles and wood piles (gloves are recommended). Clean up any debris present under decks or outdoor staircases. Spiders can hide in and under disused lawn furniture, so clean these areas up as well.
Chemical Control of Jumping Spiders
Now that entry points are sealed off, and hiding places inside and outside your home are eliminated, you can effectively use aerosol bombs or powders on resident spiders.
Sprays can kill visible spiders, and can help immediately reduce numbers in cases of severe infestations. For long-term control, use insecticidal dusts or boric acid (after you’ve made modifications to your house to minimize their presence, of course; chemicals won’t be as effective if you don’t prevent the spiders from entering in the first place).
Indoor aerosol bombs or foggers will be a lot more effective if you’ve done the work to clean up spider hiding places first. They probably won’t provide residual control for any spiders coming in later, though; seal up cracks and openings as described above, if you haven’t already.
It’s crucial that you use a product that’s labeled for use on spiders, and is labeled for indoor use; follow label instructions and do not use more product than recommended. If your first round of fogging doesn’t work, look again for hiding places outside and inside your home, or call in the pros.
Boric acid works, but a bit more slowly. The upside is that it isn’t toxic to humans. Spiders pick it up on their bodies as they go about their business, then ingest it when they groom themselves. If you’re building a house or adding a room, have the wall voids treated with boric acid.
If you spray outside: Reading the small print on the label might not be fun, but it is extremely important. Use only pesticides labeled to be effective against spiders and for use outside; spray around any crack or opening. Do not overspray. Don’t spray the firewood pile, unless you plan on throwing it all away afterwards. It is not safe to burn firewood after you’ve doused it with pesticides.
If getting the insecticidal powder in the walls and behind the baseboards of your home seems overwhelming, save yourself the headaches and call in the pros. Professional pest control operators or exterminators will tackle the job for you, saving you a lot of work and worry. Look for ones with experience with spider problems in your area.