Summer in the Treasure Valley means long, hot, dry days, green irrigated yards and a lot of time spent outside. It also means the busiest pest season of the year. Ants find the kitchen, wasps build under the eaves, spiders move into window wells and mosquitoes show up along canals and ditches at dusk.
Here’s a rundown of the most common summer pests in Idaho, where they come from and what you can do about each one.
Why Summer Is Peak Pest Season Here
Heat speeds up insect life cycles, so colonies grow and populations build quickly from May through August. Our dry climate pushes pests toward water, and in the valley the water is in irrigated lawns, garden beds, leaky hose bibs, pet bowls and the canals and ditches that run through many neighborhoods. Homes sit right next to all of it.
Ants
Ants are the pest most homeowners call about in summer. Pavement ants nest under slabs, sidewalks and driveways and trail into kitchens. Odorous house ants form large colonies and look for sweets and moisture. Carpenter ants nest in damp or damaged wood and show up as large black ants, sometimes winged.
- Wipe counters and sweep floors daily, and keep sweet foods sealed.
- Fix drips under sinks and around outdoor spigots.
- Trim plants and mulch back from the foundation.
- Don’t spray trails with a household spray, which can split a colony.
See our ant identification guide and our post on stopping odorous ants in Boise kitchens.
Wasps and Yellow Jackets
Paper wasps build open comb nests under eaves, deck railings and playsets. Yellow jackets often nest in the ground or in wall voids and get aggressive around food and trash in late summer. Bald-faced hornets build gray paper nests in trees and shrubs.
- Look under eaves and decks every few weeks in spring and early summer, when nests are small.
- Keep trash cans covered and drinks covered outdoors.
- Seal gaps in siding and screen vents.
- Leave large nests, ground nests and nests in walls to a professional.
The wasp identification guide covers the common species.
Spiders
Spiders follow food, and summer brings plenty of insects. Wolf spiders hunt along foundations, hobo spiders settle into window wells, basements and garages, and black widows like quiet, cluttered spots such as woodpiles, irrigation boxes and under patio furniture.
- Wear gloves when reaching into boxes, woodpiles and valve boxes.
- Knock down webs around doors, eaves and window frames.
- Switch porch lights to yellow or warm LED bulbs, which draw fewer of the insects spiders feed on.
- Reduce clutter in garages and store items in sealed bins.
Mosquitoes
Mosquitoes breed in standing water. Canals, ditches, ponds and overwatered lawns all play a part around Boise, Meridian, Nampa and Eagle, and so do clogged gutters, birdbaths and buckets in the yard. West Nile virus is found in Idaho mosquitoes most summers, so it’s worth taking bites seriously.
- Empty standing water at least once a week: buckets, saucers, toys, tarps and birdbaths.
- Keep gutters clean and check that downspouts drain.
- Repair window and door screens.
- Use an EPA-registered repellent at dusk and dawn.
The CDC’s West Nile virus prevention page has more on reducing bites. Mosquito control is a separate service from our regular pest plans. See our mosquito identification page for more.
Mice and Rats
Rodents aren’t just a winter problem. In summer they nest in sheds, under decks, in woodpiles and around chicken coops and compost bins, and they eat fallen fruit, birdseed and pet food left outside.
- Pick up fallen fruit and keep seed feeders well away from the house.
- Store pet food and feed in sealed metal or heavy plastic containers.
- Seal gaps around the foundation, garage door and utility lines.
- Use snap traps along walls in garages and sheds if you see signs of activity.
Start Before the Heat Peaks
The easiest summer pest season starts in April and May. Ant colonies, wasp nests and spider populations are all smaller in spring, so sealing gaps, cleaning up the yard and starting exterior treatment early keeps numbers down when July heat arrives. Waiting until August usually means dealing with larger nests and colonies that are already established.
A Summer Prevention Checklist
- Walk the outside of the house once a month and seal gaps you find.
- Keep a clear strip of a foot or so between the foundation and mulch, plants and stored items.
- Adjust sprinklers so they don’t soak the foundation.
- Keep firewood stacked off the ground and away from the house.
- Rinse out trash and recycling bins.
Summer Pest Control With ProGuard
Ants, spiders, wasps and hornets, mice and rats are core pests in our residential pest control. We offer quarterly, bi-annual and one-time service, and quarterly service plan customers get free return visits. Rodent service is included at no extra cost with quarterly service plans; traps and materials are billed separately.
Serving Homes and Businesses Across the Valley
ProGuard is based in Eagle and serves Boise, Meridian, Nampa, Caldwell, Star, Middleton, Emmett and Garden City, including commercial properties. Call (208) 352-2062 or contact us to talk through what you’re seeing this summer.