By Shannon Wright

Late last month, concerned residents around Lake Bistineau began to notice a troubling change in the landscape. The cypress trees were turning brown far earlier than expected. While the extreme heat was initially suspected as the culprit, officials have now confirmed the true cause: a cypress looper infestation.

The cypress looper, Iridopsis pergracilis, is a moth native to the southeastern United States. Its larvae, known for their inchworm-like movement, feed exclusively on cypress leaves. When infestations occur in large numbers, the damage can be severe, leading to widespread defoliation of these trees.

This is not the first time Lake Bistineau has faced such a threat. A similar outbreak in 2021 defoliated thousands of acres of bald cypress, not only here but also near the Marksville area. Now, the same cycle appears to be repeating itself.

In addition to damaging the trees, the current infestation has been linked to a recent wave of dead fish reported on the north end of the lake. Experts explain that as the looper larvae devour the cypress foliage, the leaves fall prematurely into the water. As these leaves decompose, they consume large amounts of dissolved oxygen.

This drop in oxygen, known as hypoxia, can quickly lead to fish stress and death. The situation has been made worse by the extremely hot temperatures and heavy salvinia growth, both of which further reduce the lake’s oxygen levels.

While the situation is concerning, the good news is that cypress trees are typically resilient. Most can recover from defoliation once the larvae pupate and the adult moths move on. The fish population will also recover. Still, monitoring remains crucial.

Wildlife and Fisheries officials are actively observing the infestation, not only on Lake Bistineau but also on Caddo Lake and other nearby waterways experiencing similar conditions.

For now, residents are urged to stay informed and report any unusual fish kills or changes in the tree canopy to local authorities.