Pasture Mealybug Update March 20, 2026

In Australia, the pasture mealybug emerges in early October but does not usually cause damage until early December.  This would be analogous to emergence in early April and damage in June.

As the grass is greening back up following winter, I have begun to scout pastures and hayfields where we found the pasture mealybug last fall. Thus far, I have not found any emergence.  

Keep in mind, a hand lens is necessary to find the emerging mealybugs. We are not looking for the 2-3 mm long adult, but the 0.5 mm nymph.

Photo by Stephen Biles
Our best management suggestions are to adopt what they are doing in Australia and manage for recovery. I conducted 5 field trials last year to see if we had a product that will provide control of the mealybug.  Only two of the five showed promising results. 

Some reason for the poor results can be found in what has been done in Australia. The Australians have determined insecticidal control not to be an effective means for managing the insect and it's damage. Their research has shown that waiting until damage in evident is too late to prevent significant forage losses. And the insecticide they used in their research, Movento, is also very expensive. The rate they applied would cost $48 per acre and four applications were made in their research.

This spring, we hope to study options for insecticidal control of the pasture mealybug but there are several challenges to this research. First, we hope to begin control soon after the first mealybugs emerge in the spring. This will likely be the first week or two of April, which is well before any damage will be visible. 

The second challenge is management will likely require a second or third application to control later emerging nymphs. These applications will be 2-3 weeks after the first treatment.

One important point is we currently have insufficient evidence of any insecticide providing control of the pasture mealybug in Texas. Also note that none of the products that showed potential in the 2 tests are labeled for use in Texas pastures. 

At this point, I do not have a recommendation for control, but suggest you manage the grass to maximize recovery and graze or cut hay at or before the first signs of damage.

Comments

Post a Comment

Popular posts from this blog

Managing Pastures After a Big Pasture Mealybug Year

Image
Last summer and fall we learned what Pasture Dieback was the hard way as many pastures and hayfields experienced grass loss caused by the pasture mealybug. What we know at this point is mostly what we can learn from the Australians, who have been studying the insect pest for over 10 years. The primary solutions they have found in Australia are: Manage for Recovery Improve the Pasture Sow a Break Crop Treat the Pest/Pathogen Manage for Recovery The best thing to do in the winter and spring is to manage the pasture for recovery from last year's damage.  This includes fertilizing at proper rates, managing invading weeds, and adjusting stocking rates to forage production. I understand rainfall will have a significant impact on all these management practices. Fertilization is a key to production of healthy hay and forage. While some research shows high fertility rates can also cause mealybug populations to increase, this may be manageable by grazing ...
Read more

Pasture Mealybug Presentation Slides 4-16-26

Image
Source Link:  https://futurebeef.com.au/resources/pasture-dieback/                                                         Sourch Lionk:  http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0008/1582055/Pasture-mealybug.pdf Source Link:  https://futurebeef.com.au/wp-content/uploads/2024/03/2227-Pasture-dieback-A4-brochure_WEB_FINAL.pdf Source Link:  https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0008/1582055/Pasture-mealybug.pdf
Read more

Early Pasture Mealybug Nymphs Found in Victoria Co.

Image
Pasture Mealybug Nymph Photo by S. Biles As our pastures green up in the spring, it is important for us to determine when the pasture mealybugs begin to emerge from the soil. In Australia, their research has shown the pasture mealybug is first found in early October. Since their seasons are opposite ours, their October is analogous to our April.   I have been scouting pastures for the past few months to see when the first nymphs emerge. This morning, 4/3/26, I visited several pastures that had pasture mealybug problems last year. As expected based on what they see in Australia, the first pasture mealybug nymphs were found in the three pastures I checked. The nymphs were very small, but visible. Reading glasses and a 10x hand lens help a lot. Our current management recommendations have not changed and we suggest you manage pastures to recover from previous damage by making appropriate fertilizer and weed management applications and following good agronomic practices. While ther...
Read more