Piñons un­der as­sault by scale in­sects

Home - Santa Fe Real Estate Guide - - FRONT PAGE - By Paul Wei­de­man

“ONE IN­TER­EST­ING THING ABOUT OUR PIÑONS,” ar­borist Tracy Neal said, “is that be­cause it’s so dry here, there are al­most no dis­eases they have to deal with.” But the num­ber of in­sect pests more than off­sets that ad­van­tage. Piñon nee­dle scale, the Ips con­fusus bark bee­tles, and twig bee­tles rep­re­sent a tag team that is threat­en­ing res­i­dents’ en­joy­ment of won­der­ful piñon nuts, fire­wood, and land­scapes.

The big prob­lem cur­rently is scale. “That’s why the trees look so bad right now,” Neal said. “In 2004-2005, I saw piñon nee­dle scale start crank­ing up. Look for those lit­tle crit­ters like black dots on the nee­dles. Scale doesn’t kill the trees out­right, but it loves the older nee­dles. You see th­ese trees with only the cur­rent growth on the ends of the branches. They’re like gi­ant build­ings try­ing to run on a few­so­lar pan­els: there’s not enough en­ergy to power the tree. That sets them up for bark bee­tle at­tack.”

Neal, who is also a mem­ber of the Mu­nic­i­pal Tree Board, wit­nessed the first piñon trees go­ing down from Ips in 2013, af­ter a drought that started in 2010. But the big die­off in mem­ory came dur­ing the first two or three years of this mil­len­nium.

“I was do­ing med­i­ta­tion at that time, won­der­ing about the sig­nif­i­cance of all the piñons go­ing down, and the sense I got was that they’re the ca­naries in the coal mine around here. They were yelling, ‘ Things are get­ting out of bal­ance!’”

He re­ferred to pho­to­graphs of Santa Fe in the 1800s, when no piñons are vis­i­ble in the hills around Santa Fe. “When they came back, they over­pop­u­lated. When there are ab­nor­mally dense stands of piñon and we’re in a drought, there’s not enough soil mois­ture to sup­port that many trees. The bark bee­tles were just com­ing in as scav­engers.”

As if the en­demic pests aren’t enough, ex­otic mem­bers of the in­sect world are be­com­ing more of a threat, be­cause of cli­mate change and in­ter­na­tional trade, Neal said. “The emer­ald ash borer from China is on its way south from Colorado, prob­a­bly in fire­wood; and the Euro­pean elm scale that used to just at­tack the Amer­i­can elms is now­mov­ing to Siberian elms. Things are rad­i­cally chang­ing.”

He added that a species of borer in­sect is killing honey lo­cust trees. And ar­borist Jeff Clark, the land­scape su­per­vi­sor at St. John’s Col­lege, said as­pens on the cam­pus are also de­clin­ing— and those are ir­ri­gated trees.

Clark sus­pects that ris­ing tem­per­a­tures may be at least as im­por­tant as re­duced pre­cip­i­ta­tion. “That al­lows more in­sects to sur­vive the win­ter, and this last one we had was both­war­mand dry. Our na­tive veg­e­ta­tion knows how to live in our na­tive cli­mate and if that changes, you’ve got a big prob­lem.”

We vis­ited a bare-look­ing, scale-in­fected piñon right next to Peter­son Stu­dent Cen­ter that is rou­tinely wa­tered, and Clark ex­pressed doubts that it will be alive next year. “I started see­ing piñon scale at least fif­teen years be­fore the last bee­tle out­break, and it was rare. But the last five years, it’s been out­ra­geous. Th­ese tiny in­sects feed on the old­est nee­dles, which die and drop off. This tree is down to just the cur­rent sea­son’s growth on the ends of the branches. Once it’s at this point, there’s noth­ing you can do.

“Drought af­fects older trees first, be­cause they have a lot more to sup­port,” Clark said. “Bark bee­tles thin out the for­est. When I first saw th­ese in the 1970s, they would have one gen­er­a­tion of off­spring a year, then you’d be okay. But the in­fes­ta­tion we had in the early 2000s was some­thing we’ve never seen. In some places, we had 12 gen­er­a­tions in one year. No­body had ever heard of that. And I’mwon­der­ing if scale is the same way.”

How ex­actly do we read the land­scape, in terms of mois­ture and tem­per­a­ture, to un­der­stand why scale is such a prob­lem in the cur­rent drought where be­fore it was Ips? Where are the bark bee­tles? “Most of the ones I’ve seen re­cently are only in fire­wood from some­where else,” Clark said.

Joanna Prukop was cabi­net sec­re­tary of the En­ergy, Min­er­als & Nat­u­ral Re­sources De­part­ment dur­ing the early-2000s Ips out­break. “We lost maybe 800,000 piñons in north-cen­tral New Mex­ico,” she said. A for­mer divi­sion direc­tor in the New Mex­ico De­part­ment of Game & Fish and now board chair of the Santa Fe Con­ser­va­tion Trust, Prukop re­called that by the time ex­ten­sive bee­tle dam­age was ev­i­dent, the in­sects had al­ready been at work for two or three years.

“The Santa Fe Con­ser­va­tion Trust does have a cou­ple of very ac­tive land man­agers who al­ready have con­ser­va­tion ease­ments on their land and they’re try­ing to stay ahead of some of th­ese is­sues and prob­a­bly will have to do some land­scape man­age­ment.”

What will that in­volve? “If you see dead and dy­ing trees,” she re­sponded, “they should be cut out and the­wood has to be burned or put in­side plas­tic so the bee­tles get cooked.”

Right now, the piñon-nee­dle scale in­sects are weak­en­ing a great num­ber of lo­cal trees, and Tracy Neal wor­ries that Ips will be next. “This last win­ter was so warm and dry, we’re set­ting up for an­other in­va­sion.”

Above, scale-in­fested piñons near Santa Fe Prepara­tory School. Left, a closeup of scale bugs on a branch at St. John’s Col­lege

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