Excerpts from Jim Conrad's
from the October 13, 2013 Newsletter issued from the Frio Canyon Nature Education Center in the valley of the Dry Frio River in northern Uvalde County, southwestern Texas, on the southern border of the Edwards Plateau, USA
I was botanizing with a friend when we spotted an insect on a pricklypear cactus. It was an immature bug, a nymph, and I'm using the word "bug" in its more technical sense, referring to a member of the True Bug Order, the Hemiptera. Above, you can see the nymphal bug with its hardly developed wings but very large, unusual antennae, wandering across a pricklypear pad.
While snapping the above picture I told my friend that our volunteer bug identifier, Bea in Ontario, would be tickled to see such a singular-looking bug. My friend replied, having no idea what the bug's identity might be, "Watch the common name turn out to be Pricklypear Bug... "
That's exactly what happened. Our picture shows a Pricklypear Bug, CHELINIDEA TABULATA, found from Texas and California south through Mexico and Central America into northern South America. In Australia it's been introduced as a biological control agent in an attempt to control American pricklypears who have escaped and become serious weeds.
The Pricklypear Bug isn't to be confused with the Cactus Bug, which we've introduced at http://www.backyardnature.net/n/a/cactusbg.htm.
Nymphs of that somewhat-closely-related species are bright red and they tend to cluster in groups, while our nymph not only is green but also all ranged all alone on his pricklypear. These are consistent behavioral differences between the two species.