Pricked by the thorn, continued

As adults, treehoppers are not particularly vulnerable.  They are protected, and sometimes camouflaged, by hard, helmet-like coverings.  True to their "hopper" name, they are also capable of launching themselves away from approaching danger.  However, as eggs and nymphs, treehoppers are less self-sufficient.  In order to increase the safety of their offspring, females of the species Publilia concava remain with their eggs after laying them.

A treehopper (Publilia concava) and her eggs, which are embedded in a late goldenrod (Solidago altissima) leaf vein.

By standing over their eggs, the treehoppers can not only guard the eggs, but also recruit additional protection -- in the form of ants.  In fact, the treehoppers do not simply wait for ants to find them; the presence of ants is an important factor in the females' choice of where to lay their eggs.

European fire ants (Myrmica rubra) tending the treehopper.

Like many other insects that feed on sap, this treehopper excretes excess sap as a sugary "honeydew" that is collected by ants to feed their colonies.  Importantly for the honeydew producers, the ants will also aggressively defend their food source.

Field ants (Formica sp.) tending treehopper (Publilia concava) adults and nymphs on a roadside goldenrod.

Explore some more: Ant-dependent oviposition in the membracid Publilia concava

Pricked by the thorn

Some insects can blend into the background, but only if they pick the right spot.  For the numerous true bugs (Hemiptera) that spend nearly all their time sitting on plants and drinking sap, the best camouflage could be to look like a part of the plant.

A leafhopper nymph (possibly Xerophloea sp.) sitting at a node along a plant stem.

At first glance, I mistook the leafhopper above for a new bud.  Perhaps a potential predator would have been similarly deceived.  However, there was no chance of making the same mistake with this bug:

One of these thorns is not like the others.

The two-horned treehopper (Ceresa diceros) might pass for a thorn on some plants -- but not on this rose bush.  On the other hand, the horns (and the rest of the armor-like "helmet") might be enough to discourage many would-be predators.

The false thorn on this rose bush is a two-horned treehopper (Ceresa diceros).

Explore some more: The surreal treehoppers and The strange origin of the treehopper "helmet"