This is typical for SA in Kentucky. Experience has shown me that when soybean aphid populations are detected they will most likely be found in the counties between I-65 and I-75. Also, this area generally has larger populations than found in the western production area. In addition the only SA populations that have approached threshold levels have occurred in these counties. Nevertheless, we do know that this pest is active state wide so no one should dismiss it out of hand.

This season’s buildup could be a little on the early side. There is no way to know exactly why but I suspect that this summer has had more days with relatively mild temperatures (mid 80soF) compared to “average” years in which we will see many days with temperatures in the mid to high 90soF. Research has shown that SA reproduction and survival decreases with the high temperatures that often occur in Kentucky summers.

While an increasing population in central KY does not indicate an immediate problem, it does serve as a road sign. Certainly those with soybean interests in central KY should be actively sampling for SA. I have two major concerns: 1) we have a great many late planted beans. Photoperiod not withstanding, we are likely to have  many bean fields in vulnerable stages, late into the season.  2) History has shown that the largest populations of SA in Kentucky have occurred in late August and September. Perhaps these two factors could allow for larger populations early in the year (August) than our history would predict.

Soybean producers and consultants should continue to scout fields for SA and other pests. Central Kentucky could be the “bell weather” for any important populations in the state. The decision threshold remains the same at:

An average of 250 aphids per plant
and
An increasing population
(thus requires more than one sample date)
and
Soybean plant stages younger than R6

The most straight forward method of determining the need to treat is through the Minnesota Speed scouting system. An explanation of the method and a worksheet can be viewed (and down loaded) from:
http://www.soybeans.umn.edu/crop/insects/aphid/aphid_sampling.htm

This system is designed to provide a simple method that reduces labor and time when deciding whether or not to spray. It is not useful for describing the SA population or changes in the SA population. A sampler can make a decision using as few as 11 plants and never any more than 31 plants. The scout only has to count up to 40 aphids per plant. At that point the plant is discarded and another is selected. This is repeated for at least 11 plants or until the guide provides a clear decision to: spray, do not spray, or resample in 7-10 days.

If needed, insecticides recommended for use on SA can be found in ENT-13, Insecticide Recommendations for Soybean – 2009. This publication is available through your County Extension Office or on the web at:
http://pest.ca.uky.edu/EXT/Recs/welcomerecs.html
Our history with this insect tells us that we are unlikely to need a treatment but insects are very adaptive, and local populations can vary from the norm. Keep an eye on them!

Cicada killers, velvet ants, and Scolia wasps can be seen over or in lawns now. These insects are intent on carrying out their daily chores and tend to disregard humans but they attract attention and can cause a painful sting if disturbed.

Cicada tunnels usually have a distinctive U-shaped collar of loose soil around the opening. Individual tunnels are 12 to 18 inches long and may extend 6 to 12 inches deep. There is an average of 15 egg-shaped cells as side chambers to a tunnel. Each contains a paralyzed cicada and a developing wasp larva. Development will be completed next year with the wasps emerging in late summer.

The presence of large numbers of cicada killers in a area is a sign of ideal conditions for them plus an ample supply of cicadas. Over the long term, developing a thick turf may help to reduce wasp numbers. Direct treatment of burrow openings with Sevin dust may provide some short term control.

There has been some confusion lately in field crops regarding pre-harvest intervals (PHI) and the length of residual activity against target pests.  Some have treated the PHI of pesticides as the length of residual control against pests, but this is NOT the case.  If this were the case, there is an example of a PHI for miticides that is 300 days until harvest.  It would be great to have 300 days of residual activity against mites, but it isn’t so. The opposite is true as well, just because one pesticide has a shorter PHI than another does not mean that is residual effectiveness is shorter. PHIs have been determined and are required to ensure our food safety. They are based on dietary exposure risks, not on pest-killing power in the field.