Louisiana citrus producers were already on alert for the Asian citrus psyllid since it was discovered in the state last year. Now growers have to be on the lookout for the diaprepes root weevil, an insect from the Caribbean that has been in Florida since the 1960s. The insect was discovered in a citrus orchard in lower Plaquemines Parish in the fall of 2008.The Asian citrus pysllid is causing concern for citrus farmers in multiple states. The bug carries what is called the greening disease that it passes onto citrus trees that can kill the trees. The root weevil can cause problems for multiple plants. According to Louisiana State University (LSU) AgCenter entomologist Natalie Hummel, the ‘“has a host range of about 270 different host plants including a number of ornamental plants and trees as well.”
In a story on the Delta Farm Press website Hummel describes the destruction the weevil causes. First the weevil lays eggs on leaves (a female can lay up to 5,000 eggs during its lifespan), then the larvae feed on the leaves. Next the larvae fall to ground and burrow in where they feed on the plant’s roots. The adults also feed on leaves. As a result of the bug’s nature, growers have to undertake an expensive defense posture to protect their crops from the weevil at all three stages of its life.
LSU AgCenter researchers recommend a treatment plan “that includes a growth regulator that causes the females to lay sterile eggs, foliar sprays when adults are emerging and an insecticide barrier on top of the soil to kill the adults while they emerge.” At this point the state is trying to prevent the weevil’s spread across the state, so farms where the weevil has been discovered may be put under quarantine, meaning no plant material can leave the property. The pest can also affect sugar cane and sweet potatoes.
To combat the Asian pysllid and prevent greening disease, officials in the parish are using helicopters to spray “all the trees for the psyllid in a single day.” Alan Vaughn, LSU AgCenter county agent recommends people not bring in citrus plants from out of state because of the potential for the insects and diseases to spread.
To Delta Farm Press story on the citrus situation in Louisiana click here.
Posted: 09/11/09
