There have been several calls about plant bug populations ranging from 10 – 25 immatures per drop cloth. High numbers of green stink bugs are also being seen in more localized areas. Here's a battle plan to combat heavy infestations:
1. Plan on making two applications, and make the second application on a 4-5 day interval. One application will almost never be enough when populations are three or more times threshold. You can get in a vicious cycle of weekly spraying if you delay the follow-up application for even a couple of days.
2. The spray interval is probably more important than the insecticide selection, but use the best treatments at reliable rates. Again, plan on two sprays. You can mix it up, but use a pyrethroid as a component in at least one of these applications. Your selection should depend on what you have in the field … plant bugs, stink bugs, bollworm, all of the above. A good list follow is below:
Acephate or Orthene at 0.75 lbs ai/acre or more
Bidrin at 6 – 8 oz
Transform at 1.5 - 2.0 oz (in approved areas only)
Endigo at 4.5 – 5 oz
Bidrin XP II at 10 – 12 oz
Diamond at 6 – 9 oz
Vydate at 12 – 16 oz
Pyrethroid insecticides tank mixed with …
Acephate at a minimum of 0.5 lbs
Bidrin at 4 oz
Diamond at 6 oz
Vydate at 8 oz
Dimethoate 4E at a minimum of 8 oz
3. Do not use only a pyrethroid if targeting tarnished plant bugs. Data collected this week shows where pyrethroid insecticides provided 0 – 40% control of tarnished plant bugs. This includes Brigade or other bifenthrin products. Pyrethroids are a good tool as a tank mix partner, as suggested above, but they are not good enough to be used alone.
Information provided by Scott Stewart, University of Tennessee Extension entomologist.