Picture ID 77609

Picture of unidentified spider

Comments & ID Thoughts

Found these on back of an oak leaf. Can someone tell me if they are a clutch of eggs or a cocoon? And what kinds?

  • Submitted by: 
  • Submitted: Aug 13, 2019
  • Photographed: Aug 13, 2019
  • Spider: Unidentified
  • Location: Beausejour, Manitoba, Canada
  • Spotted Outdoors: High foliage (includes trees and tree trunks)
  • Found in web?: No
  • Attributes:
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These are galls, which the tree grows in reaction to an irritant such as wasp larvae. The gall, in turn, nourishes the larvae. This is probably Callirhytis furva. The presence of these galls usually isn’t enough to harm the tree, unless the tree is already distressed and vulnerable to a heavy infestation.