Questions about spiders
Why do some spiders hang a leaf in their web?
Q: “I have noticed that spiders sometimes
have a leaf hanging in their web. Can you tell me why they do
this? Aren't they just advertising to insects that the web is
there and the spider is ready to eat them?”
From Alyssa, Sunnybank Hills
A: Hi Alyssa. Thank you for your interesting question. There are several reasons that spiders may put a leaf in their web.
1. Some spiders around our creek use leaves as an important part of their webs. The classic example is the amazing bowl spider (Cyrtophora exanthematica), which uses leaves at the end of a thin branch to fashion into a spectacular bowl-shaped web. You can see photos on our bowl spider page.
2. Leaf-curling spiders use a dead or fresh leaf as their home. Although you don't often see the spider inside the curled leaf, it keeps its legs on the web threads to feel the vibrations of any insect that flies into it. See photos on our leaf-curling spider page.
3. Spiders are remarkable engineers. Not only can they make intricate webs, but they know how to keep the strands taut while they are building. From our observation, some seem to use a dead leaf or other object as a plumb — a heavier object that keeps the weight of the web balanced. This may be only short term while they are constructing, or it may stay longer.
They don't use only leaves for this purpose. The photo at left shows a small seed pod hanging from a golden orb web spider's web. When we took this photo, several golden orb web spiders were constructing adjoining webs above.
They will use any item they can pull up to the web, but leaves are the most common.
— Critters of Calamvale Creek editor