Aceria macrorhyncha – You may have noticed these little bright red pustules on the upper surface tree leaves and wondered what they were? These are plant galls, and this one in particular is caused by a tiny mite ( they belong to the same group as spiders) which feed on the leaves of Sycamore (Acer pseudoplatanus). The mites are small enough to pierce and feed on individual plant cells, causing the surrounding cells to enlarge and multiply to form the gall. In the final image you can see the holes on the underside of the leaf, beneath the galls. Not sure what the red jelly-like stuff is. Double-click images for a closer look-see.
© Peter Hillman ♦12th May 2020 ♦ Local woodland path, South Staffordshire ♦ Nikon D7200