Do nothing...........pests come followed by the predators, which get rid of the pest.
Start spraying crap everywhere and you kill the good with the bad, destroying the natural balance.
The more biodiversity, the less chance of pests building to harmful levels.
Pests are inevitable, but if you can resist doing anything for a week, the problem usually sorts itself out........as in......aphids may appear, but are then followed by ladybirds or hover flies which then clean the aphids up.
Planting companion plants such as marigolds, brings in the good guys.
Can't say I have ever in 40 years of outdoor cultivation, had a pest problem that caused any sort of real issue...........a bit of damage, yes, but destroyed crops.........never.