Soybeans

Cooperative Extension

Disease Management

Sampling Guidelines

Pest	Sampling Method
Growth Stage: Seedling to Pre-Bloom
Bean Leaf Beetle, Mexican Bean Beetle	Using a drop cloth placed between 2 rows, shake the plants in 6 foot row in 10 sites in a field, count the number of beetles found in 6 foot of row in each site, for Mexican bean beetle note the presence of pupae/eggs at each site, estimate defoliation at each site
Grasshoppers	Take 10 sweeps in 10 sites and count the number of adults and nymphs
Thrips	Examine 5 leaflets in 10 sites for the presence of thrips, check top and undersides of the leaves
Potato Leafhopper	Take 10 sweeps in 10 sites and count the number of adults and nymphs per 100 sweeps, sampling should be done when the foliage is dry
Growth Stage: Prebloom – Podset
Japanese beetle, Green Cloverworm, Silver Spotted Skipper	Using a drop cloth placed between 2 rows, shake the plants in 6 foot of row in 10 sites in a field, count the number of insects found at each site and estimate defoliation
Spider Mites	Examine the underside of 5 leaflets in 10 sites for mites; also note the presence of mite eggs and note that amount of damage
Growth Stage: Podset – Maturity
Spider Mites	5 leaflets in 10 locations
Bean leaf beetle, Mexican bean beetle, Green cloverworm, Silver Spotted Skipper, Yellow Striped Armyworm, Beet Armyworm, Fall Armyworm	6 foot of row in 10 sites using a drop cloth
Corn Earworm	5 sweeps in 5 to 10 locations walking down the row

Insect Thresholds

Pest	Sampling Method
Growth Stage: Seedling to Pre-Bloom
Bean Leaf Beetle, Mexican Bean Beetle	Using a drop cloth placed between 2 rows, shake the plants in 6 foot row in 10 sites in a field, count the number of beetles found in 6 foot of row in each site, for Mexican bean beetle note the presence of pupae/eggs at each site, estimate defoliation at each site
Grasshoppers	Take 10 sweeps in 10 sites and count the number of adults and nymphs
Thrips	Examine 5 leaflets in 10 sites for the presence of thrips, check top and undersides of the leaves
Potato Leafhopper	Take 10 sweeps in 10 sites and count the number of adults and nymphs per 100 sweeps, sampling should be done when the foliage is dry
Growth Stage: Prebloom – Podset
Japanese beetle, Green Cloverworm, Silver Spotted Skipper	Using a drop cloth placed between 2 rows, shake the plants in 6 foot of row in 10 sites in a field, count the number of insects found at each site and estimate defoliation
Spider Mites	Examine the underside of 5 leaflets in 10 sites for mites; also note the presence of mite eggs and note that amount of damage
Growth Stage: Podset – Maturity
Spider Mites	5 leaflets in 10 locations
Bean leaf beetle, Mexican bean beetle, Green cloverworm, Silver Spotted Skipper, Yellow Striped Armyworm, Beet Armyworm, Fall Armyworm	6 foot of row in 10 sites using a drop cloth
Corn Earworm	5 sweeps in 5 to 10 locations walking down the row

Soybeans | Commercial Crops | Sustainable Production Systems | Cooperative Extension | University of Delaware

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