Economic thresholds – Mirids in mungbeans

This threshold assumes all green, brown and crop mirids and broken backed bugs produce equivalent damage, and that third instar (wing buds are present) nymphs onwards are as damaging as adults.

See the Beatsheet’s mirid image gallery for pictures of different species and life stages.

Enter your estimated:

  • control cost per hectare (include both product and application)
  • crop value per tonne

to receive a break even threshold (where the benefit in saved yield is equal to the cost of the control measure) expressed in number of mirids/m2.

Quick reference break-even table

Quick reference threshold values for a range of control costs and crop values are provided in the look-up table below.

 Control cost
per hectare		  Crop value per tonne
$ 700  $800  $900 $ 1000 $ 1100 $ 1200 $ 1300
 $10 0.24 0.21 0.19 0.17 0.15 0.14 0.13
 $15 0.36 0.31 0.28 0.25 0.23 0.21 0.19
 $20 0.48 0.42 0.37 0.33 0.30 0.28 0.26
 $25 0.60 0.52 0.46 0.42 0.38 0.35 0.32
 $30 0.71 0.63 0.56 0.50 0.45 0.42 0.38
 $35 0.83 0.73 0.65 0.58 0.53 0.49 0.45
 $40 0.95 0.83 0.74 0.67 0.61 0.56 0.51
Note: Values in the quick reference table are based on a measured yield loss of 60 kg/ha for every mirid per square metre inflicted over a 28 day period. Plants can compensate for early damage so don’t spray too early to reduce the risk of (a) needing a 2nd mirid spray, and (b) flaring helicoverpa. Newer mirid insecticides can increase mirid thresholds considerably (by a factor of 2 or more).