No. These insects are visible to the naked eye, and therefore prohibited. Why are they not readily seen? Often, it is because of the background which they are in. In lettuce, for example, there are green thrips. Since the lettuce is also green, the thrips are not easily seen. If, however, the thrips would be on a surface of a different color, they would be readily visible 8.
An insect or microbe which is not visible to the naked eye, even if it is visible under a microscope–is permitted 9.