Cacti Comeback

In one of the better known success stories of biological control, prickly pear cacti (Opuntia spp.), invasive in Australia, were nearly wiped out by the Cactoblastis moth (Cactoblastis cactorum) in the 1930's. Now comes news that prickly pear may be making a comeback. In Southern Australia, populations of the cacti are starting to spread, but in scattered remote areas, making biocontrol difficult. One scientist suspects that they are dealing with a different species, Opuntia robusta, and that a search for a new biocontrol is necessary.

Over here, you sexy crayfish!

In an effort to rid their rivers of the invasive North American signal crayfish (Pacifastacus leniusculus), British scientists are setting pheromone traps in the water to make males think they've found a mate. According to this article in the Independent, crayfish that take the bait will be killed humanely. (Oh come on, you know they'll be cooking up seafood gumbo! :-) You can read an older story about this from the BBC by clicking here.

Doing what vines do

Old World climbing fern (Lygodium microphyllum) is the most invasive plant in Florida, surpassing even melaleuca (Melaleuca quinquenervia), according to this article from the Orlando Sentinel. Native to Australia, the fern is taking over portions of the Everglades, creeping along the ground, finding its way up trees, and smothering them with dense foliage that blocks out sunlight. It's difficult to fight such a species with herbicides, since it tends to be intricately intertwined with its victims. Researchers are currently studying two insects as potential biological controls, but for now the invasion continues. You can listen to an audio program on the topic by clicking here.

Time is running out!

I finally finished the second item for sale in my CafePress shop: the Invasive Plants Wall Clock. It features 12 differect invasive plant species and their common and scientific names. I put a lot of work into getting the photos just right, and I'm pretty pleased with the results (I ordered one for myself so I'll know for sure in a week or so). You can get your own for $11.99 + s/h (I make a paltry $1.00 from the sale of each clock).

Flipping the Birds

How can I resist posting a link to a story that has a quote like this: "Would you really like to eat your supper if a bird came up and took a dump in the middle of your T-bone steak?" That's how farmer Jerry Seimers feels about starlings (Sturnus vulgaris), which have invaded his land by the thousands. The flocks have resisted every attempt to scare them off, from loud music to fake owls, and now the USDA has stepped in to help Mr. Seimer get rid of the starlings by feeding them poisoned food pellets. No one's happy about having to poison so many birds, but the farm is already benefiting from the reduced starling populations, with native birds already starting to reappear.

More Carping

Officials in Austin, Texas are proceeding with their plans to introduce grass carp (Ctenopharyngodon idella) into Lake Austin to fight the invasive aquatic plant Hydrilla (Hydrilla verticiallata), according to this article in the Austin American-Statesman. As previously reported in this blog, tests have shown that the carp, which are also invasive species, are unlikely to escape from the lake into nearby river systems. The fish make their grand entrance this February, followed by herbicide application and mechanical hydrilla removal in the spring. They join another enemy of hydrilla, the asian hydrilla leaf mining fly (Hydrellia pakistanae), which was introduced to the lake in October 2002.

Thanks to D.V. for sending in the link to this article.

Zapped!

According to this article in the Daily Southtown, officials are so pleased with the success of a temporary electric barrier in the Chicago Canal, used to keep Asian carp from invading, that they have decided to build a permanent barrier. The new barrier, which will cost $7 million, will be paid for by the Illinois Department of Natural Resources and the U.S. Army Corps of Engineers, and is built to last 30 years...will it be enough?