That’s right, flea beetles…alligator weed flea beetles. Let me start from the beginning.
Our fight against invasive species has led us to the Black River, a quiet river between Pender and Bladen counties that is home to the oldest trees east of the Mississippi River, giant bald cypress trees that are 1700 years old, amazing! But trees are not what I want to discuss this time, maybe another day. What I am interested in sharing with you is our fight against the invasive aquatic plant called alligator weed.
It’s a plant from South America that is growing on and along the Black River here in North Carolina. Alligator weed is a problem because it grows in large mats and clogs up the river flow, which can starve the water of sunlight and oxygen in turn harming the native creatures and plants that live there. In an effort to control the alligator weed we partnered with North Carolina Department of Environmental and Natural Resources (DENR) Aquatic Weed Program on a project that released 3000 alligator weed flea beetles, a small beetle that dines exclusively on alligator weed, on a 5 mile stretch of the river. The beetles are a native to South America too and have been used extensively in Florida to control alligator weed with much success! The beetles we released were collected in Florida and shipped to us Fed Ex.On Thursday Dan Ryan (Southeast Coastal Plain project director), Margaret Fields (North Carolina Field Office Invasive Species Specialist) and I went back out on the river in our kayaks to where we released the beetles to monitor their progress and we were quite surprised by our findings! We didn’t observe any beetles, unfortunately. Our hypotheses is that due to extreme heat and lack of rain the beetles once released onto the alligator weed never had the chance to lay eggs. There was evidence on some of the alligator weed of beetle munching but we didn’t see any beetles or larvae. We did however see evidence of grazing, maybe by a deer or other herbivore, which was a pleasant surprise as we didn’t think anything ate alligator weed other than the flea beetles.
We will continue to monitor the river where the beetles were released for the remainder of the summer. I will be sure to keep you updated.
Here is a cool video that my intern took while we were cruising along the Black River when we released the beetles in June, the driver of the boat is Rob Emens with the DENR Aquatic Weed Program and talking to him is me! You can see in the video I am pointing to the alligator weed which is all of the green vegetation seen growing along the banks of the river.