Black Cutworm & Armyworm Moth Captures Show a Big Increase

Doug Johnson, Extension Entomologist, University of Kentucky

Fig. 1 Black cutworm moth.

Black cutworm (BCW) and armyworm (AW) moths captured in the IPM traps at the UK-REC in Princeton, KY show a substantial increase for the trap week ending Friday, April 10th. In the case of BCW, 37 moths were captured when about 8 would be expected. For armyworm, 541 moths were captured when 119 would be average at this time. Captures for both of these pests are significantly greater than their rolling five- year averages. In addition, if the armyworm counts continue to increase at this rate, the population will approach the outbreak levels seen in 2006 & 2008. These are years when known pest problems either caused loss or required extra insecticidal control. See the Insect Trap Graphs on the UK-IPM webpages.

2015 IPM Training Rescheduled for March 24

The IPM Training canceled on March 3 has been rescheduled for Tuesday, March 24. Program will be held from 9 am till 3 pm CDST at the University of Kentucky Research & Education Center at 1205 Hopkinsville Street in Princeton Kentucky. Program topics include update on weed resistance and new herbicide technology, invasive insect pests, using biosolids, 2015 state apiarist report and UAVs for scouting and monitoring crops.

Program is approved for 5.0 CEUs for CCAs (3.0 Integrated Pest Management, 1.0 Nutrient Management and 1.0 Professional Development) and 3 pesticide education hours (2 general and 1 specific) for pesticide applicators in categories 1A, 4, 10 and 12. For more information email plucas@uky.edu or call (270) 365-7541 ext 218.

2015 IPM Training Scheduled for Wed. March 4th at the UK-REC is canceled!

***CANCELED***

The 2015 IPM Training Scheduled for Wed. March 4^th at the UK-REC is canceled!

Due to expected dangerous weather conditions the 2015 IPM training program scheduled for Wednesday March 4, 2015 at the UK-REC in Princeton, KY has been canceled. A rescheduling date is being considered for later in March. Please check back for further information. We are sorry for any inconvenience, but we cannot take chances with people’s safety.

Storing Wheat

Proper prior planning! This is the essence. Let there be no doubt that preventing a problem in stored wheat is by far more effective and economically sound than solving a problem that could have been prevented.

Prepare bins two weeks ahead of time.

Insure your bins are in good repair. Even small holes will allow insect entry. Be sure the roof does not leak!

Do not store with carryover grain.

Thoroughly clean all equipment from the combine to the bin to avoid seeding the newly harvested grain with insect pests.

Consider fumigation of areas below perforated floors and in aeration ducts. Get a professional fumigator to do this dangerous task, correctly. Save your life and money in that order.

Treat the insides and around the outsides of bins with an approved insecticide.

Bin dry wheat if possible at 12 to 12 ½ % moisture.

Move air through the grain to reduce temperature any time that is possible until the grain temperature is below 50 F. Consider installing automatic fan controllers.

If you use an insecticide applied to the grain, make sure it is labeled for that purpose. If you use a grain dryer do not apply insecticide before the grain moves through the dryer and until the grain has cooled after exiting the dryer.

Check your grain regularly. At a minimum look in the hatch and use your nose to perform a “sniff test” to detect out of condition grain. Insect traps can be a good indicator of problems if you will learn to use them. Do not wait until delivery time to look for insects. That is often too late for any remediation.

For the full story check Kentucky Pest News #1198 at:http://www.uky.edu/Ag/kpn/kpnhome.htm

FHB Risk, May 7, 2009

An email from Don Hershman had the following image. The image is from the FHB Risk Assessment Tool at Penn State. http://www.wheatscab.psu.edu/riskTool_2009.html
Much of the wheat-growing area is in red or yellow, meaning that we have high to medium risk for FHB, according to the model.

See Don's post from May 6, 2009 for more details about head scab and management options.

Armyworm Flight 2009: No consistent story; but there will be caterpillars!

Doug Johnson, Extension Entomologist
Dept. of Entomology, University of Kentucky

Early captures of armyworm moths appeared to indicate a larger than normal population for 2009. However, after several weeks of monitoring it appears that the capture counts do not indicate an obvious major outbreak situation. This is particularly true of the Princeton, KY trap. We do not yet have enough historic data to know how to interpret the Lexington trap data. However, this does NOT mean that there will not be any problems. [Please see: How to Use Insect Graphs from the UK-IPM Trap Lines at:

http://www.uky.edu/Ag/kpn/kpn_09/pn_090324.html

to review how to use the trap data.]

There will be armyworm caterpillars in susceptible host (corn, small grains, grass forages), as there are every year. In fact if we apply the day degree model to the very first moth captures there are likely caterpillars already appearing in both western and central Kentucky. These will be among the earliest of caterpillars. Remember if you are in a location warmer than where our traps are located then caterpillars will appear earlier. If you are in a cooler location they will appear later. I have received one report of armyworm caterpillars on the heads of wheat (though I have not seen this myself) from a southern Pennyrile area county.

While moth captures in our traps do not indicate a major outbreak year, we certainly have experienced weather that selects for the survival of the caterpillars. Typically armyworm populations do better in cool wet weather. At least in western Kentucky we have certainly seen such weather. Historically, grass forages and corn suffer the most damage from armyworm, but small grains are certainly at risk, particularly if the caterpillars are feeding on the heads.
Scouting techniques and thresholds are available in our IPM Manuals available at:

http://www.uky.edu/Ag/IPM/manuals.htm

If needed, insecticide recommendations are available in our Insect Management Recommendations for field crops available at:

http://pest.ca.uky.edu/EXT/Recs/welcomerecs.html

These publications may also be available at your local County Extension office.

Even though our trap counts do not suggest a big problem, the weather patterns certainly imply that scouting susceptible hosts is still important. I request that anyone that finds an armyworm infestation that requires treatment or should have been treated, please let me know at: doug.johnson@uky.edu.

FHB May Be Severe in Kentucky this Year

Wheat across central and west Kentucky (which makes up the bulk of the wheat acres in the state) has been in various stanges of flowering since early last week. Many fields are currently at full anthesis or slightly beyond.

As we all know, it has rained a lot over the past 5-8 days across much of the state. This wet weather, as well as temperature and humidty conditions, have resulted in a moderate to high FHB risk across most of central and west Kentucky. The windy weather before it started to rain, and now the rain, has greatly hindered fungicide applications aimed at Fusarium head blight suppression. Some spraying was probably possible on Monday and Tuesday of this week, but the current storm system moving through the state will effectively eliminate the possibility of ground spraying for today (Wed), probably tomorrow, and maybe into Friday-Saturday. Aerial application will also be challenged. The bottom line is that most wheat fields in the state will be highly vulnerable to FHB. By time spraying is possible again, it will be too late to spray most fields due to label restrictions. Plus, from a practical perspective, once infection has occurred, fungicides (which are not that good against FHB in the first place) are of little value.

I rarely prognosticate epidemics, but it seems that nothing is in our favor, and everything is pointing towards an significnat FHB episode in the state. Fields that were in full flower early last week may escape significant infection since they were beyond the most susceptible infection stage by the time the rains began. Likewise, crops that have yet to flower, may escape infection. But the acres that fit either of these two scenarios is rather small compared to the whole.

If it is any consolation, remember that when FHB pressure is high (such as I believe it is right now), fungicide-treated crops can still be severely impacted by both FHB and DON. That is, only 30-50% suppression can be expected when fungicides are applied under the best of scenarios. One final point. Some may be thinking that they wish they had sprayed while their crop while it was still heading out, but before flowering. Doing so would have provided little benefit against FHB due to the limitations of fungicides against FHB and the fact the new tissue that emerges after application would be (for all practical purposes), unprotected.

I am sorry to have to predict this gloomy situation. We will know how accurate my words are by mid-May. That is about how long it will take for FHB symptoms to be expressed.

Current Status of Fusarium Head Blight

Low temperatures and breaks between rain events (up until this past event) have kept the FHB predictive model from indicating even moderate FHB risk (up until now). The block of rain we have just experienced has changed that, so the FHB models are now showing moderate to high risk for spore release in much of central and west KY. I believe conditions will be ripe for spore release beginning Monday night. Spore release happens mostly happens at night and is actually favored more by high humidity than rain. Rain can give you splashing of spores, but it also washes spores out of the air and off of plants. Infection, on the other hand, requires free moisture, so infection generally is greater when spores have been released and transported to heads during dry, but humid, periods at night, followed by rain the next day or so to support infection. It is complicated and that is why we don't always have a lot of FHB. It is rather hard to get!

I encourage growers with decent crops that are just entering flowering to to spray as much as they can Monday and Tuesday and into Wed. I realize that getting sprayers into fields will be hard, so that is a complicating factor that may prevent many fields from being sprayed this year. It is what it is. More wet weather is anticipated beginning Wednesday. I have had several questions asking about how late one can spray and still get FHB suppression. That is pretty simple. Most labels restrict application to early flowering or at most 50% bloom. Thus, there is not much of a decision to make. The days to harvest restriction is very specific for all fungicides labeled for wheat.

The key thing to remember is that according to the FHB models, up to the present moment, not many spores have been available to spread to heads, let alone infect heads. But after today and the gloves come off unless it turns hot and dry fast. This could be a bad FHB year in light of the lack of spraying and/or difficulty in getting fields sprayed. But the timing of this rain coinciding with the completion of head emergence or flowering in many fields is hard to deal with. If fields had sprayed before the rain, it might have been too early to get good coverage on the heads.

Updated Wheat Scab Risk Management Tool

Our colleague, Don Hershman, said that the Fusarium Head Blight (Head scab) Risk Management Tool has been updated and is available at: http://www.wheatscab.psu.edu/riskTool_2009.html

The tool provides a general risk level for wheat in a given area.

Once into the tool, identify what date you want to select (such as today).
Then identify the wheat model (spring wheat or winter wheat).
Finally, select the state in the map that applies.

A color-coded map will appear with green being little risk, yellow being medium risk and red being high risk. This model can help when deciding to make a preventative fungicide application.