Surprise inside

Earlier in the year, the crabapple (Malus sp.) tree in the backyard was buzzing with bees.  Now, it is covered in small, sour fruits.  I keep checking the fruits to see if anything will eat them, but so far they have been left alone.  Instead, I have noticed that many of the crabapple leaves are getting rolled up and eaten.

A rolled crabapple (Malus sp.) leaf.

Curious to know what was inside, I began carefully unrolling the leaves.  Within the first few leaves I found white silk, insect frass (the black droppings in the picture below), and ladybugs.

A convergent ladybug (Hippodamia convergens) in a rolled crabapple leaf.

However, most ladybugs are predators, not herbivores.  Something else must have been rolling and eating the leaves -- and then been eaten by the ladybugs.  I kept looking.  On about the fifth leaf, I finally found a leaf roller caterpillar.

A leaf roller caterpillar inside a crabapple leaf.

Having found only harmless (to me) insects inside the leaves, I started unrolling the other leaves with less caution.  However, I soon discovered that the leaf roller caterpillars were not the only ones rolling leaves.  As I peeled open another leaf, I saw long, spindly legs -- and I immediately released the leaf.  I brought a flashlight down to the garden so that I could peek inside through the narrow opening without further disturbing the leaf.  With the aid of the flashlight, I found that the legs belonged to a spider guarding its egg sac.

A spider and egg sac inside a rolled crabapple leaf.