In South Texas, a bamboo-like reed called carrizo cane is wreaking havoc.
It’s been described by border patrol agents as “Sherwood Forest”. Attempts to tackle the weed – including cutting, burning and bulldozing – haven’t done the job.
Now the state has a new trick up its sleeve – one that’s smaller than a pinhead.
Carrizo cane isn’t new to Texas, according to Etter. It’s been here since the time of Christopher Columbus, specifically along the Rio Grande, but it only became an issue once Texas suffered from several years of drought. Carrizo soaks up a lot of water – often killing native plants – but that’s not the only problem it creates, Etter says.
“When the border security crackdown occurred, officials were realizing that people were hiding in the cane,” Etter says. “It was actually dangerous for border officials to track migrants that were trying to evade officials.”
Carrizo can grow 30 feet tall, clustered in groups called stands which are incredibly dense..
“If a [border patrol] dog were to go in there the dog would just get lost. … The dog would also get tired and would not be able to conduct its job,” Etter says. “Border officials have been known to go in there and not find anybody after just hearing there was somebody nearby. It’s very precarious.”
But there’s a plan to combat the carrizo cane biologically, Etter says: a federal Department of Agriculture entomologist wants to release the French Arundo wasp to feast on the carrizo.
“Essentially [the wasps] … are the host species for the cane,” Etter says. “They eat the cane, lay eggs in the cane, and by dominating the cane they essentially are able to stunt its growth. Then it’s going to not grow as thickly … and as tall.”
Etter says this will allow native plants to grown back; it’s also the least environmentally-damaging method, compared to using chemicals or tearing up the river bank (causing erosion). The scientist who called for the Arundo wasp says there’s little threat it will turn into an invasive species itself either, according to Etter.
“The scientist … has done thousands of tests in quarantine and determined this is very host specific,” Etter says. “That means that the bug only eats carrizo cane. [Scientists] say that there really is no threat because … they don’t eat anything else. We don’t have anything to worry about.”