Think of the brown part like a little buggy hardhat. That shell protects the soft critter within from insect and pesticide attack. (but not my fingernail!)
We have a similarly protected insect on our eucalyptus trees. The little psyllid within spins a sugar-sap cone that foils predator bugs.
Last edited by czygyny; 09-03-2013 at 06:05 PM..
Reason: clumsy syntax
I strongly recommend Sue Bottom's pdf, it's a reference, accessible and helpful. My only 2 remarks on it are:
- USA centered, the chemicals are not available for us Europeans
- no organic/soft/alternatives strategies, in some cases, there are.
Now it's a great source for ID and action, and it's been revised this spring.