My aunt today saw the following objects on roses in her garden enter image description here

enter image description here and asked what it is but nobody could tell her yet, but it seems to be some kind of parasite or some caterpillar eggs. As you can see, they differ in size since they appear in larger groups, but each egg (I call it so since I have no better name) has a diameter of about 1 cm. On the outside, there are red spikes. Loaction is Germany.

Would be great if someone could tell me what this is and whether it should be removed from the roses.

Thanks in advance

  • $\begingroup$ Please insert the pictures into your post rather than links. $\endgroup$
    – tyersome
    Jul 24 at 20:08
  • 2
    $\begingroup$ Looks like galls; growths of the plant in reaction to an irritant. Generally not necessary to remove them. $\endgroup$ Jul 24 at 20:25

These are not eggs, they are rose leaf galls caused by the spiny rose gall wasp (Diplolepis bicolor) larva that encases itself inside the gall and then matures and chews a hole in the gall to escape in spring, laying its eggs on a newly emerged leaf bud. The larvae generate the gall in the fresh leaves, perpetuating the cycle.

Remove the galls in late summer or winter if you want to get rid of the larvae. Personally, I like them, so I would leave them. New larvae will generate new galls, but they will usually only be a few each year.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.