Trouble Looms with the Pasture Mealybug
Folks, if you have not yet heard about this grass pest, I suggest you do a little research as it appears to be very serious. We already have screwworm knocking on our door and I figured that would be bad enough, but now we have a completely new pest that can totally destroy grass fields. At least with the screwworm, we know how to treat it in our livestock and how to eventually eradicate it again. This pasture mealybug is completely new to us and has the potential to have a major impact on anyone that grows grass.
The pasture mealybug was officially identified in south Texas this past September. It has already proved to be a devastating pest in areas where it has been found. The insect’s larva is the stage in which it feeds. These larva feed on the juices from the plant, but in doing so they inject a toxin into the plant that kills the plant. It not only kills the top growth, but the entire plant including the roots. In cases where it was found in south Texas, the plants were totally dead all the way down to the roots and the plants did not resprout. Obviously, we are not looking at damage like we might see with armyworms or even stem maggot- this pest kills the whole plant.
Many of you may have seen mealybugs before. We see them mostly on ornamentals and house plants, however, this is a totally different mealybug. It only feeds on grass and appears to feed on all types of grass. Thus far, there have been no bermudagrasses or other grasses including annual hay grazers and sorghums, that it will not feed on. One of the researchers was in a field infected with the insect and went home and accidentally infected his San Augustine lawn and they killed his whole yard. You think your native grasses and old-world bluestems will be safe, think again. Reports indicate that at a native seed repository in Texas City the pasture mealybugs killed every variety of native plant they had at the location.
The insect itself does not move long distances; most of the movement appears to have been mechanical. Unintentionally and probably unwittingly, custom hay balers and roadside shredders are the primary mode of transportation for the pest at this time. Researchers do believe it can be moved in and on hay bales so that is another means of transporting the insect over long distances. Moving cattle from an infested field will transport the insect as the adults will stick to their legs.
The darned bug is extremely hardy- it goes quite deep into the soil to lay eggs. As a result, it is thought our winters, even the hard ones, will not kill out the pest. Thus far, researchers have had very limited time to research products to kill the insect, but there is some hope. Using our normal grasshopper, armyworm, and stem maggot products have shown to have no effect and probably cause more harm than good due to the damage they do to beneficials. Beneficial insects look to be very important in controlling the pest.
This is all very new information and researchers will be focusing on the pest and conducting many trials to learn more and find ways to control the pest in the coming season. It is important to watch for the insect and to let me or someone know if you think you see it this coming growing season. It will be much easier to treat a field or two in an effort to slow its spread than to wait until it has spread across the county. The closest reported findings of the insect right now are in Robertson County near Franklin and Kendall County near Boerne. Both counties are approximately 2.5 hours away and it is my hope that it will not make it this far north and west, at least not until we learn how to feasibly control it. We do have a pasture mealybug publication with more information available at the office so just call or come by and we will get you a copy.