Cotton ranges from emerging to 3-4 leaf plants. Weather forecasts are not optimistic for rainfall so treating for insect pests of seedling cotton is not likely profitable.
The pests we can expect to find on young cotton includes thrips, aphids, and mites. I have not seen fields with insect populations requiring management.
Seed treatments are typically good for 3 weeks following planting and most fields are were planted more than three weeks ago.
The water needs for the plants are not very high right now so the primary issue seen in most fields is wind damage. This wind damage can resemble thrips injury. Thrips will usually be in the terminal on the newest leaves. If the newly forming leaves are undamaged, the injury is probably from the wind.
If you think you have a thrips problem, check the plants for thrips prior to considering controlling them. The Economic Threshold for thrips is 1-2 thrips per true leaf, but cotton growing in a warm environment with adequate moisture can sustain higher thrips populations without economic damage.
Aphids have been found in small pockets of some fields. Aphids do not usually cause economic losses to cotton prior to bloom. My suggestion for aphid management on seedling cotton is usually to let them go for a while and see if natural control takes care of the problem. Most of these aphid populations will be short lived and should not require an insecticide.
The threshold for treating a field for aphids is 50 aphids per leaf when averaged across the field. This level is rarely encountered early in the season.
If mites are found on the plants, mark the location and return in a few days to see what injury they are causing. There is no set threshold for treating mites so watch for leaf injury. I do not expect to see treatable levels of mites.