Rockingham County horticulture agent Kathryn Holmes first brought this video to my attention last month in an email where she asked "do we need to worry about these"?
I fired off a quick reply that these were larval thrips (probably eastern flower thrips), which we most certainly have in NC but are nothing to worry about and certainly do not warrant washing your strawberries in soap. We do not typically see fruit injury from thrips in NC strawberries, so I do not generally recommend pesticide treatment for these insects. See this post from earlier in the spring on thrips. I was not aware, however, that this video had been picked up by other sources until I was searching for local media stories on the strawberry crop and found WRAL news blogger Monica Laliberte's post on the same topic. Since this information is being passed around more widely, I decided to write up a short post to clarify the video for those that may be interested.
The video was produced by Star-K Kosher Certification, a company that assists businesses in receiving kosher certification for food products. Most Insects are not kosher, which explains why they are interested in removing insects. What does this mean for the rest of us who do not keep a kosher diet? Nothing new! We do not have any new non native thrips species recorded recently from NC strawberries, which means that the insects that may be present on our fruit are the same as have always been there. Many thrips are generalist omnivores--they feed on pollen, plants, and even the eggs of other pest insects. The larvae are present on strawberries because the eggs they hatched from were laid there. They will feed for 1-2 weeks (depending on the weather) and then molt to adults themselves and move on to the next host. Thrips are present in numerous other places in the environment--in flowers, in your lawn, on your peaches, and on your house plants--like many other arthropods.
Strawberries are not washed before packing (to do so would dramatically shorten shelf life), and a good water rinse will remove field dirt and insects. Those that are not removed are ultimately harmless. I know I would much rather eat a strawberry rinsed in water with a few remaining thrips (or mites) than one covered in soap residue or one treated with unnecessary pesticides used to assuage the fears of consumers coming across a video like the one above!