Caterpillar on pear tree

Observation - Caterpillar on pear tree - UK and Ireland. Description: This began as a strange cobweb-like bundle on the pear tree branch and then black dots appeared within it, which appeared to hatch into orange caterpillars with black heads

This began as a strange cobweb-like bundle on the pear tree branch and then black dots appeared within it, which appeared to hatch into orange caterpillars with black heads