Simply apply this inexpensive filler into the cracks to seal.
How to seal siding from bugs.
There are a few spots in siding where you can successfully introduce insecticides.
Seal small cracks and gaps in your siding under 1 4 inch wide using an acrylic latex caulk.
First vinyl siding has tiny weep holes at the bottom of each course panel to allow moisture to escape.
Instead i d probably just let the siding thoroughly dry in the sun checking for signs of bugs during that time then go ahead and use it.
Caulk is cheap easy to apply and can go a long way towards keeping bugs out.
Add caulk around window frames as well as around any air intake or exhaust grilles.
I take advantage of these tiny holes using pyrethrin aerosols and an injection straw.
I d use dusts but the ready made hole is far to small.