Roseau Cane Update

Jan 1, 2018

While you oooh and ahhh over the intricate use of flowers and plants ornamenting today's Rose Parade floats in Pasadena, California, Louisiana officials continue to fret about the die off of a necessary marshland plant — Roseau cane.


"We've now got observations of the invasive scale in 13 parishes," reports Jim Pahl with the Coastal Protection and Restoration Authority.

Pahl has been coordinating research into the tiny insects — a form of mealy bug — which kill off the cane and result in the rapid conversion of marshlands to open water.

"There was some hope we might be able to use the European variety — transplant that into areas where some of the Gulf and Delta varieties had died back. Unfortunately, the European variety as well is basically getting hammered by the scale insects."


He says one hopeful sign this fall was regrowth from roots, but with new canes also came more scale insects.

"Some areas are recovering a little better than others. We are seeing re-infestation at some level. And it's kind of an open question of, is that re-infestation going to prove fatal."


Another big question has been whether agricultural crops are vulnerable to the pest. Pahl says they tested Roseau cane's near relatives to try and find out.


"Sugarcane, rice, sorghum, and corn," he ticks off on his fingers. "The nymphs were able to survive on sorghum; no infestation on any other plants."


Spraying is ineffective for killing the critters, and because of other life forms in the marsh — birds, fish, reptiles, shellfish — it's prohibited by the EPA. In the scale's native habitat, the usual method of control for these Asian invaders is burning. That’s a problem, because the worst infestations are in the Bird’s Foot Delta of the Mississippi River.


"Basically, you can’t throw a stone too far in the Bird’s Foot, without hitting oil and gas infrastructure," Pahl says.


When Pahl updated the CPRA board late last month about the ongoing research into the cane die-off, members asked about funding to cover the studies, and to combat the infestation.



CPRA director Johnny Bradberry said that’s a whole other problem.


"Until we get some of this studying done, we don’t have any leverage to say, ‘This is what I need, because this is what’s going to happen if I don’t do this,'" Bradberry remarked.