61: Pinyon Needle Scale
I write to you from Arapahoe, Ute, and Cheyenne land. I am interested in learning about the different animals that live in the place where I was born. Before we start with today’s animal, I want to emphasize that biological classification as understood by western society has its roots in racism, sexism, and transphobia – here’s a good explainer about why.
It’s time for another edition of interesting arthropods! The Pinyon Needle Scale (PNS) (Matsucoccus acalyptus) (also piñon depending on who is spelling it) is a tiny, black, sap-sucking insect that will appear as a tiny black bump on the surface of a pinyon pine needle. By sucking the sap, they rob the needles of their ability to perform photosynthesis and thus kill them, weakening the pine trees themselves. Although PNS rarely kills the trees, an infestation opens the door for bark beetles and other pests to move on in and finish them off, or for drought (like we’re experiencing now) to kill them.
Pinyon pines grow throughout southern and western Colorado and as far north as Denver closer to the foothills. The trees produce edible nuts that have been a staple food for Native people living in the southwest for millennia; you can also find them in restaurants serving traditional southwestern cuisine throughout Colorado, New Mexico, and Arizona.
(Remember the pinyon pines because we’ll be coming back to them when we talk about the Pinyon Jay sometime in the future.)
This description of the life and mating cycle of PNS from Dr. Carol Sutherland of New Mexico State University is long but evocative:
“The male PNS [emerges in autumn] to crawl down the twigs to branches to the trunk and beyond to the duff layer (old needles, dead weeds, rocks, etc.) where they overwintered. They will mature and molt into a minute winged ‘gnat’ with no mouthparts and long filament ‘tails’ of wax. If you’re outdoors doing spring cleanup around your trees, these will be those ultra-tiny ‘gnats’ that will get in your face, nose, ears, etc…. Just as these males are flying in early spring, the mature female scale insects emerge from their ‘black beans,’ walking down the needles to the twigs, branches, and limbs, and sometimes to trunks, where they congregate and start producing lots of waxy ‘lint’ filaments---the ‘dryer lint’ you’ll see on the trunks of infested trees and the undersides of some limbs. Males find them there and mate. Then the males die (no mouthparts, no fat left for energy and it’s ‘curtains’ for them) as the females finish maturing their now-fertile eggs. Females lay their eggs by the zillions in the ‘dryer lint.’ The eggs hatch into even tinier nymphs, called ‘crawlers,’ which start their own journey up the trunk to the limbs to the branches to the needles where they settle on the green needles at the very ends of those you photographed. These nymphs plug their piercing-sucking mouthparts into the green growth and begin to feed on the nutritious sap of photosynthetic tissues; as they molt, they lose tiny red eyes, antennae, and legs. They also transition to that ‘bean shape,’ exuding assorted waxy-looking waste products on their surfaces. They continue to feed and mature (whether and how many more times they molt, I don’t know), but they never move again until next fall (males) or next spring (females).”
Evolution!!! Incredible!!! Imagine all of the things that had to happen in order for this to be the life cycle of these tiny animals in a relationship with a single type of tree!