Research hint: when you have a pest problem on an edible plant, Google the name of the plant and “UC Davis.” What comes up is UC Davis’ handy Integrated Pest Management info sheets, evidenced based information on all kinds of problems. This is how I figured out that a small insect called the western flower thrip (Frankliniella occidentalis), was noshing on our nectarines.
Thrips damage the fruit when it is small. The scars enlarge as the fruit matures.
How do you manage thrips? UC Davis notes:
Western flower thrips overwinter as adults in weeds, grasses, alfalfa, and other hosts, either in the orchard floor or nearby. In early spring, if overwintering sites are disturbed or dry up, thrips migrate to flowering trees and plants and deposit eggs in the tender portions of the host plant, e.g. shoots, buds, and flower parts.
Thrips are often attracted to weeds blooming on the orchard floor. To prevent driving thrips into the trees, do not disc the cover crop when trees are in bloom. Open, weedy land adjacent to orchards should be disced as early as possible to prevent thrips development and migration of adults into orchards.
It was an exceptionally dry year which may have contributed to our thrip problem. And perhaps some mulch and weeding around the base of the tree is in order. UC Davis goes on to suggest monitoring methods as well as organic controls if that’s your cup of tea.
The scarred fruit gets rotten on the tree and is unappetizing. We did get some unblemished fruit, but there was enough of a thrip problem to warrant monitoring next year.
Did you have thrip problems this season?