Winter service
Treat the eggs in January or chase the adults in April
A water-resistant dust treatment aimed at overwintering egg cycles, combined with an indoor treatment.
What overwinters, and where
Most of what bothers you in July does not leave for the winter. It overwinters, and a great deal of it overwinters as eggs tucked into sheltered gaps on the outside of the house: window wells that collect leaves and hold warmth, the spaces in retaining walls, and the cracks and crevices along the foundation line. Those eggs sit dormant through the cold and then hatch more or less together on the first sustained run of warm days, which is why a spring infestation feels so sudden when it was in fact scheduled months earlier.
Why dust rather than a liquid
A liquid applied to an exterior wall in winter has two problems. Snow melt and rain wash it off the surface, and liquid does not travel far into the dry voids where eggs actually sit, so you end up treating the face of the wall rather than the gap behind it. A water-resistant dust holds where it is placed through wet weather and moves into cracks, crevices and voids. It is paired with an indoor treatment, because anything that came inside for the winter is inside for the duration.
Nature's Way — Fully insured and bonded. Utah applicator licence 4001-18960. Call (801) 513-4106.

The season most people cancel is the one that pays back
Winter looks like the obvious month to skip. Nothing is crawling and nothing is flying, so the problem appears to have solved itself. Along the Wasatch Front that instinct is almost exactly backwards.
Treating in winter
The target is stationary, concentrated in a short list of known locations, and not reproducing. That is about as favourable as pest control conditions get, and Utah’s real winter gives a long reliable window in which it holds true.
Treating in May
The same population, after it has hatched, dispersed across the property and begun breeding. One of those is a defined job and the other is several months of catching up. A false spring in February makes it worse, because a warm week starts hatching early.
Window wells · retaining walls · cracks and crevices · plus indoor treatment