leaf galls

This fallen leaf has galls all over it, lumps or complicated structures that look like capsules containing something mysterious.  Galls are made by one of 1500 species of gall producers -- mostly insects and mites.  Some galls form on leaves where insects feed on the plant matter, or lay eggs.  Galls may also develop as a response to infections by fungi, bacteria, or viruses.  Dissecting the gall is the only sure way to tell what caused it. That's a whole different adventure!

goldenrod

 

To complement all the blue and purple flowers around the pond this week, the Goldenrod has unfurled its blooms.  Solidago species, commonly called Goldenrods, are in a genus of more than 100 species of flowering plants in the aster family, Asteraceae.

Goldenrods are often blamed for allergies, but they have sticky pollen and rely on insects to move most of it.  The wind borne pollen of ragweeds and pigweeds are to blame for 'hay fever' in late summer.

These plants are habitat for a large number of insect species. Blooming in late summer, they are a critical nectar source for many bees, butterflies, and moths to fortify themselves before freezing weather comes. 

what is it May 2020

I found an unfamiliar object on a twig laying on the ground near the pond. Deer have browsed the willow shoots in that area, and this was cut but left behind. The object seemed like a gall or growth rather than a seed pod.  It has dried leaves curled around it, and looks to be attached to the twig with a web-like or woven material.  I asked my friends on Botanical Wanderings for ID help -- it is most likely the cocoon of a native silk moth. If so, it should emerge in the next few weeks. Hopeful, I tied it to a sandbar willow branch near where I found it, since willow a host plant where giant silk moths lay their eggs.

Worms? Monsters?

Worms?  Monsters? These are “finger galls”.

Insects or mites feeding on a leaf, or laying eggs on or injecting eggs into part of a plant, cause galls to form. The leaf tissue reacts by increased production of normal plant hormones and localized plant growth.  The outcome is an abnormal plant structure called a gall.  These look like tiny wiggly "fingers" protruding from elm leaves.

Gall formation usually occurs in late spring during the accelerated growth period of new leaves, shoots, and flowers.  This is when insects might be feeding on plant tissue, or emerging in their life cycle to lay eggs.  The gall-making insect develops inside the gall and the gall continues to grow as the organism feeds and matures.  In autumn and winter, some birds feast on the insects they find inside galls, especially on goldenrod.