Mid-Coast IPM

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. I conducted a similar research test on a field of WW-B Dahl grass near Port Lavaca. 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 is planned to be continued by sampling the hay bales for live mealybugs. More to come...

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.    ...

We are at the time of the growing season where our primary insect pest is stink bugs. This is the case in sorghum, cotton and soybeans. While each crop has its own species causing damage, the fields are important to scout to identify the pests causing potential yield and quality losses. In grain sorghum, many fields are being harvested but there are some fields that are still susceptible to stink bug injury. The primary stink bug of concern in sorghum is the rice stink bug .  The economic threshold for stink bugs in sorghum changes as the crop matures; becoming less susceptible as it approaches hard dough as depicted on the graph below.  For detailed information on the economic thresholds of stink bugs in grain sorghum, look HERE . We are also finding sorghum aphids (AKA sugarcane aphids) in a number of fields in Refugio County. Check these fields to prevent harvest issues from the honeydew produced by the aphids. Cotton is also susceptible to stink bug damage from early bloom...

It seems every day we get phone calls, texts, and emails showing us another county where the pasture mealybug can be found affecting the pastures and hayfields. The map below shows the latest information on the spread of the mealybug in Texas. If you have mealybugs in a county not shown in green, call, text or email me.  361-920-1138 or biles-sp@tamu.edu   Over the past few weeks, we have been conducting insecticide tests to determine what insecticides will be useful in managing the pasture mealybug populations. None of the insecticides we think will control the pasture mealybug are labeled for control of pasture mealybug in pastures in Texas. The only one labeled in pastures in Texas is Sefina, which is labeled for aphids in pastures. The insecticides were applied at 13 GPA using TT11002 flat fan nozzles. All applications included a non-ionic surfactant at 0.25% V/V. As of 14 days after treatment, we were not able to visually separate treatments and I expect it will take anot...

This past week we have seen corn leaves in several fields that have turned red. In the past few years, we have been concerned about the symptoms of corn stunt which is transmitted by the corn leafhopper. In the fields I looked in, the leaf reddening was caused by two things: pasture mealybug or poor pollination.  Some corn plants had yellowed or reddish leaves on the bottom of the plant. These plants were found only on the field edges up to 3-5 rows in, and bordered either the grassy roadside ditch or pastures. The grass in these pastures was infested with pasture mealybugs and the insects were moving into the corn fields.  Pasture mealybug damage to corn leaf So far, I have only found the damage to affect the plants on 4-5 rows into the field. I do not think this is economic damage; mostly because the leaf damage is below the ear leaf. Leaf damage cause by poor pollination In the other fields where I found leaf reddening, the red leaves were above the ear. Inspecting the ears...

The crop tours for this year are as follows: Refugio County     June 10     Austwell Community Center in the morning     Bonnieview Community Center in the afternoon DeWitt County    June 9     Gruenau Hall in the Afternoon Event Flier Victoria County     June 16     Dacosta Hall in the morning Calhoun County     June 16     Extension Office in the Afternoon Event Flier More details to come.