Connie’s Comments by Connie Strunk, Turner County Extension Educator—Agronomy  November 13, 2009

            This past week I have enjoyed driving around seeing all combines in the field finally able to reap the fruits of their reward.  In just a week we have come a long ways but most of you are aware that there is a long ways to go until we are done with harvest.  Since harvest is finally upon us, it will only be a matter of time until the Asian lady beetles move-in or (in some cases) invade our homes. 

The Asian lady beetle was first documented in South Dakota in 1996.  The Asian lady beetle is now considered a nuisance indoors and is actually considered a beneficial insect for agriculture.  How?  Both the immature and adult stages of the Asian lady beetle feed on soybean aphids, scale insects, and other soft-bodied arthropods.

Asian lady beetles are about 1/4-inch long and 3/16-inch wide (basically oval shaped) and are usually a pale orange or red color.  Asian lady beetles can be distinguished from other lady beetles by the letter “M” marking on their thorax.  Although present in most specimens, this “M” marking may be absent in some individuals.  Counting the black spots on the wings is not a good way of identifying Asian lady beetles because they could vary from 0 to 19!

Asian lady beetles do not destroy wood or any structures in buildings.  The beetles typically do not bite humans and pets but in some cases they have.  If the Asian lady beetles become agitated they may excrete a yellow liquid that may stain your carpet and walls.  They appear to enter buildings only for the purpose of seeking shelter.  Also, reproduction and feeding do not occur indoors.  The beetles that make it through the winter will leave their over-wintering sites in early spring to start looking for prey and start reproducing in the field.

Preventing entry into your home may be the best way of controlling the Asian lady beetles (and other insects such as attic flies) in your home.  Small openings in the siding, eaves, windows, doors, and utility pipes must be sealed before these insects start to move.  They are able to fit into tiny openings (gaps of 1/16^th of an inch or less). 

If you have sealed all openings and you are still struggling to keep the Asian lady beetles out you can apply a spray to the outside of your home to kill the beetles before they get in.  The most effective sprays are various synthetic pyrethroids such as permethrin, cyfluthrin, and lamda-cyalothrin.  You will want to concentrate along doors, windows, and the south and west sides of your home.  You may want to consider hiring a professional pest control company for this outdoor application.

There is no effective chemical for use indoors.  Using insecticides indoors for control of the lady beetles is not typically recommended unless the infestation is very heavy, and then professional pest control advice should be sought.  When all else fails, a vacuum cleaner or broom is often the best response once the beetles have come indoors.  Once collected release the beetles outdoors under some vegetation cover such as shelterbelts, shrubs, and compost piles. 

  Unfortunately, there is no “quick fix” or easy answer to annual lady beetle invasions.  Vacuuming, pest proofing, and properly timed exterior insecticide treatments can provide relief but will not prevent entry of every single beetle.

For more information about Asian lady beetles visit Dr. Mike Catangui’s website at http://plantsci.sdstate.edu/ent/entpubs/alb_SD.htm or contact me at the Turner County Extension Office at (605) 297-3112.

For your information:  SDSU has developed a website dealing with damaged grain (in this case moldy corn) which you can reach at http://sdces.sdstate.edu/weatherdamagedgrain/index.cfm. 

The mycotoxin survey that I mentioned a few weeks ago is underway and I am still in need of a few samples.  If you are interested in this free assessment please feel free to contact me.  I can either come and get the samples from you (whether that is out in the field, on the farm, or at the co-op) or you could drop off your samples here at my office.  All that is required is about 5 lbs of shelled corn (1 gallon size Ziploc bag) with a description of what field (where in the county it came from) so we can see how the mycotoxin levels play out throughout the state of South Dakota.  It would be nice if you are able to provide the variety, etc. but I will take what I can get!  Thanks in advance for your help with this survey.  The few samples that the testing lab has received have indicated that mycotoxin levels are lower than initially feared.  That is a reassuring thing to hear but they have only received a small number of samples to test.  

For more information or if you would like to receive email updates about the moldy corn situation please feel free to contact me at the Turner County Extension Office at 605-297-3112 or by email at connie.strunk@sdstate.edu.  I hope we have some more nice weather and that harvest continues without any more trouble!  We have certainly seen it all this growing season whether it comes to weather conditions, insects, or diseases.