By Rob Leeds
January 20, 2014
January kicks off the winter meetings, and pesticide recertification. Mark your calendars for our Delaware County one which will be held on March 11 at the Radnor Township Hall. I will have more information on this later.
One bright spot about January is that our daylight is gradually getting a “little” longer every day. But, we still have plenty of winter left. Those sub-zero temperatures we had a few weeks ago didn’t last real long, but it may have been long enough to do some damage on those pests that overwinter in Ohio.
Normally Ohio seldom gets cold enough to be a factor in causing significant mortality during the winter months. However this winter may prove to be different. A good example of what can happen occurred during a similar cold spell in 1983 that caused significant mortality to the Mexican bean beetle, which killed off our state-wide problem that was beginning to occur in soybeans.
We will not be able to tell what might happen until we actually see possible lower numbers during the growing season. And remember that all these insects are capable critters; they tend to overwinter in protected places, and growers also need to consider heavier snow cover is a good insulator. Ron Hammond, OSU Extension Specialist says to not include pests such as true armyworms and black cutworms in early summer, and potato leafhoppers later in the summer in these thoughts. According to Hammond, these pests migrate into Ohio during the growing season, and what happens with the weather in states much further to our south has more impact on them.
Finally, Hammond says that there are situations to remember concerning a few specific insect pests. There first is with the soybean aphid. Because we expect the two year cycle to continue, 2014 is already expected to be a very low year. So if soybean aphids are extremely low this year, it is probably because of the two cycle, and not the cold spell. But it will be interesting to see what happens then in 2015 with this aphid and if there is an impact and carry over for the two years. The other insect is the western corn rootworm. We have had low numbers of this pest the past few years, including last year. There is no reason at this time to expect anything different this summer. Thus, if numbers of rootworms are again low, will it be from having had low numbers already, or was it the cold spell?
Bean leaf beetles and Mexican bean beetles on soybean are the main pests that we will need to watch. Japanese beetles and slugs on both soybean and corn, and then newer concerns, western bean cutworms and Asiatic garden beetles on corn. All these overwinter in Ohio, and perhaps the cold spell will have an impact on them!
Rob Leeds is the Ag/NR OSU Extension Educator for Delaware County