Mesquite Bug Flash Mob
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Yesterday, Rene Clark and I went over to Saguaro National Park (West) to see what we could see. For those of you not familiar with Tucson, Saguaro National Park is established in two distinct locations, on the east and west sides of town. Both locations are chock full of Saguaro cacti, but the similarities end there. The two branches of the park are at different elevations and there are subtle differences in habitat and ecology between the two. Also, Saguaro West differs significantly from Sabino Canyon — it’s warmer in the winter and hotter in the summer, and the vegetation, aside from Saguaros and some other overlapping species, is different. Fauna is different as well. There are species of lizards, for example, found at Saguaro West that do not exist at Saguaro East and Sabino Canyon, and vice versa.
Rene and I did not have much success in finding anything unique. We did see a lizard that definitely does not live in Sabino Canyon, but had no success in photographing it. We found other lizards in Saguaro West that were much more cooperative than are their compatriots over at Sabino Canyon, and I’ll feature a couple of photos of one species tomorrow.
We were nearing the end of out hike when Rene suddenly stopped and pointed at the upper branches of a mesquite tree. There was a large mass of something alive up there, bigger than my fist, and it was definitely moving. As we looked closely we realized that we were staring at nymphs of the Giant Mesquite Bug.
These insects are fascinating. As they mature they go through several distinct larval stages (instars). The nymphs of each instar have a unique physical appearance that changes as the insect progresses to the next stage. As nymphs these insects are colored a brilliant red. Why? Entomologists theorize that these nymphs taste absolutely awful to a would-be predator, so the young Mesquite Bugs effectively advertise their presence, with the red color functioning sort as a stop sign for predators. It’s not unusual to see the nymphs clustered in a large mass as is the case here. Possibly, they find strength in numbers — maybe a large, bright red mass of insects is a more potent warning than can be conveyed by a single individual.
Image made with a Canon 5Diii, 180 f3.5L Macro Lens, assisted by Canon 600EX-RT Speedlite, ISO 250, M setting, f16 @ 1/160.