Predatory bugs for thrips:
Most Thrips move down into soil, rockwool or other synthetic growing media to pupate. This is the first stage at which to control Thrip populations, using Predator Nematodes. Often after two months, regular application of Nematodes alone gives good control. However, for heavy or persistent infestations, we recommend using Nematodes in conjunction with above-ground controls. Your choice will depend largely on the environment in your growing area.
Thrips Predator Mites (Amblyseius cucumeris) are most effective under conditions of 70-85% humidity, against all species of Thrips. They will also eat an occasional Spider Mite, and other small pests. However, reports have been poor in low humidity environments, so use these predators in greenhouse and other interior locations with high humidity levels only.
Ladybugs (Hippodamia convergens) eat over 5,000 Aphids and other soft-bodied pests during their one-year lifetime. Ladybugs are one of the few beneficial insects that can be stored, dormant, in the refrigerator for up to a few weeks, depending on the time of year, as long as they don't freeze or dry out. This allows you to use a few at a time, as needed.
Pirate Bugs-The newest Thrips control, Pirate Bugs (Orius insidiosis) also eat Spider Mites, insect eggs, aphids, and small caterpillars. Shipped as nymphs near hatching or adults ready to use (no choice).
Green Lacewing Larvae/Eggs-Looking like tiny alligators, Lacewing larvae (Chrysopa rufilabris) voraciously attack almost any prey they can grab.
Praying Mantis-Fun garden pets, Mantids eat anything & everything they can catch! Praying Mantis (Tenodera sinensis) make wonderful backyard pets, and constantly entertain while they eat insects all Summer long.
may explain why you only saw the one...