Well it depends on the insect I suppose. With ants they eat it and
carry it back to the hive where it kills the queen, so one good
treatment should last for quite a while if it doesn't get washed away
the day it's applied. I'm my area we have some thing people around here
like to call a palmetto bug but it's really just a cock roach. They
feed on the compost in flower beds an such, it works on them the same
way.
I would say the effect was very effective
it hasn't even been a week yet since applying and I haven't seen any
ants since. It's also a bait so you would want to keep it out side for
sure. Now the crickets maybe be another story as I haven't been back
under the house since applying but I also have heard a peep from them
either.