group of larvae of bird-cherry ermine yponomeuta evonymella pupate in tightly packed communal, white web on a tree trunk and

biology birdcherry branch buckthorn butterfly caterpillars cocoon crawl dots eggs entomology ermine evonymella fauna flora foliage gathering green group host infestation infested insect larva leaf leaves macro moth natural nature nest outdoors parasite pest plant pupate silk summer trunk web white wildlife young yponomeuta