Counting pod sucking bug counts
Green vegetable bugs (GVB) are considered the most important pod sucking bug pest in pulse crops due to their abundance, wide-spread distribution and rate of reproduction, however other species can still cause severe damage when present in large numbers. A conversion to green vegetable bug equivalents (GVBEQ) allows an assessment of overall potential damage of a mix of bug species compared to the likely damage of GVB.
If no nymphs are present, the adult counts for each species can be converted to GVBEQ by simply multiplying the sample counts by the appropriate conversion factors:
|Pod sucking bug species||Relative damage conversion factor|
|Green vegetable bug (GVB): Nezara viridula||1.00|
|Brown bean bugs (BBB): Riptortus & Melanacanthus sp.||1.00|
|Redbanded shield bug (RBSB): Piezodorus oceanicus||0.75|
|Brown shield bug (BSB): Dictyotus caenosus||0.75|
|Green stink bug (GSB): Plautia affinis||0.10|
Green stink bug has only minor impact compared to the other PSB species, so is not currently included in this calculator. If numbers are high, divide by ten and add to the GVB column.
If you have nymphs in your fields, a further conversion to green vegetable bug adult equivalents (GVBAEQ) is required, because bug nymphs are less damaging than adults. These calculations are included in the calculator below.
Remember to take an adequate number of samples to ensure your counts are representative of what is present in the field.
Photos of a range of life stages of these bugs are available at the Podsucking bugs image gallery.
Action threshold calculator
Note that pulse crops for the edible market have severe penalties for damage, so these thresholds prioritise quality over yield. See the explanation at the end of the calculator for more details.
Spraying before podfill is unlikely to be economically worthwhile.