Pasture Mealybug in Hay - Updated

Will the pasture mealybug be moved in hay bales?  This is one of the many questions asked over the past year. My thought has been, yes, the mealybug can move in hay bales, but we have no research on this topic.

The problem with the mealybugs staying in cut grass is, as the grass dries, there is less plant sap for the mealybug to feed on. So the logical assumption is the insects will leave the grass. 

A few weeks ago, Dr. David Kerns shared some data on this showing most mealybugs left the grass but about 5% were found in the cut grass 48 hours after cutting.

We conducted a similar research test on a field of WW-B Dahl grass near Port Lavaca. The field was sampled on June 30 prior to cutting on July 1 and the cut hay was sampled on July 3, two days after cutting.

The results were similar to those of Dr. Kerns. In the Port Lavaca Test, about 100 mealybugs were found in a similar amount of grass as the 2 sq ft samples taken prior to cutting the grass. This is 8.7% of our pre-cutting counts. 

The test was continued by sampling the hay bales for live mealybugs. On Friday, July 10, we sampled the hay bales from this field by getting 4 core samples from each of four bales. The core sample was 5/8-inch cores and sampled 20 inches into the bale. After putting the samples in the Berlese funnels for three days, we counted what was in the catch cups.

No mealybugs or other insects were found in the samples from the bales of hay, except for one spider. This may demonstrate the hay is free of live mealybugs or the sampling method was not sufficient to find the insects. The test should be repeated to further understand the survival of mealybugs in hay bales. 

***** Live Mealybugs found in Hay Bales *****

Dr. Kerns checked hay bales 14 days after baling and found live mealybug adults and nymphs in his samples. This confirms that mealybugs can survive at least 2 weeks in a hay bale.  I plan to recheck the hay bales and increase the number of core samples taken. 

On July 8, we initiated an insecticide trial to evaluate insecticide timing for control of the mealybug.  the grass had not begun to green up as is our current recommendations.  No mealybugs were found on the grass plants or observed on the soil surface. 

July 14, I visited the field and found mealybugs were back on the grass. I intend on a second application timing soon.





Comments

Post a Comment

Popular posts from this blog

Pasture Mealybug Update 5-22-26

Image
This week we were able to set up and spray an insecticide control test near Cuero, TX.  This test has products we have hope will be successful in controlling the insect, but there is still some uncertainty until we get the data in a week or two.  The other factor is that none of these products are labeled for control of mealybugs in pastures.   Yellow Sugarcane aphids and Pasture mealybug nymph There have been some challenges finding the mealybugs in the fields.  In the field with this study, the majority of mealybugs found are very small nymphs.  We have several observations regarding scouting for the mealybug.  1) Time of day may be important for scouting pastures. It seems we can find more before noon than after the day has heated up. 2) Larger mealybugs may drop off the plant when disturbed so being careful when handling the plants may increase your chance of finding the insects. Moving the mealybug from infested fields to un-infested fields...
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

Pasture Mealybug Scouting, Management, and Recovery

Image
1.       Scouting a.       Check edges of damaged areas more than in the middle of dead grass. b.       Look for leaf damage symptoms such as yellowing and red leaves. c.       Look for mealybugs on the underside of leaves, especially the lower leaves. d.        Check the soil surface and thatch below grass canopy for mealybugs. Often a majority of the mealybugs may be in the thatch and on and in the soil. e.       Mealybugs can be as large as 5 mm in length or as small as 0.2 mm. If larger mealybugs are being found, there may be many more small mealybugs that are difficult to see. f.         We have not determined a producer/consultant method for determining the size of the populations while in the field. However, if mealybugs are easily found, they are likely above an economic level. 2.    ...
Read more