Soybean Aphid (Aphis glycines)

Excerpt from Chapter 2, Field Crop Protection Guide, Order this publication

Table of Contents

1. Description
2. Integrated Pest Managment Options
   • Seed Treatment
     • thiamethoxam – Cruiser 5 FS
     • thiamethoxam + metalaxyl-M + fludioxonil - Cruiser Maxx Beans
   • Foliar Treatment
     • cyhalothrin-lambda – Matador 120 E
     • cyhalothrin-lambda – Silencer 120 EC
     • dimethoate – Cygon 480, Lagon 480 EC
3. Related links...

Description

Figure 1. Close up of soybean aphid. Note black-tipped "tailpipes".

For more details see OMAFRA factsheet Soybean Aphid (Order #04-059).

Integrated Pest Management Options

Seed Treatment

Foliar treatment at threshold is the recommended method of control. However, seed treatments for the control of other soil insect pests may provide early-season protection (up to 40 days after planting) from early infestations of soybean aphids.

Comments
For use in commercial seed treaters only. Provides only early-season protection against soybean aphids and will not protect crop against typical mid-to-late-season aphid infestations.

Comments
For commercial application only. Compatible with Rhizobium-based inoculants. Check with inoculant manufacturers for details prior to use. Do not graze or feed livestock on treated areas for 45 days after planting. Provides early-season protection (up to 60 days after planting). Will not protect crop against typical mid-to-late season aphid infestations.

Foliar Treatment

Foliar treatment is the recommended method of control for soybean aphids. Aphid infestations are more likely to cause yield reduction if the plants are already suffering from drought conditions or another stress factor.

Scout fields frequently. Apply foliar insecticide when threshold of "250 aphids per plant with increasing populations" has been reached in the R1-R5 stage of soybeans. If aphid populations do not appear to be on the increase above 250 per plant, do not apply insecticide, as it will kill off the beneficial insects that are keeping the aphid population in check. Aphids are then likely to increase quickly in the absense of their predators and could easily reach threshold.

For further information on scouting techniques, OMAFRA weekly scouting results, thresholds and management options, see OMAFRA Publication 811, Agronomy Guide for Field Crops, as well as the Ontario Soybean Growers website at www.soybean.on.ca.

Comments

Ground and aerial application. For best results, apply during the early morning, before temperatures rise, and during the evening, past the heat of the day. Use higher rate when conditions favour rapidly increasing populations or when crop canopies are dense, resulting in poor spray coverage. Select nozzle size, type and pressure to produce a medium spray. Use 100-200 L water/ha. Maximum 3 applications/yr. 21 days to harvest. Do not re-enter treated areas until 24 hr of treatment.

Comments
Ground application only. For best results, apply during the early morning, before temperatures rise, and during the evening, past the heat of the day. 21 days to harvest. Maximum 3 applications/yr. Do not graze or harvest treated forage, straw or hay for livestock feed.

Comments

Use high volume, high pressure and ensure good coverage. Do not feed or allow livestock to graze on treated forage. Do not apply within 30 days of harvest.

Related links...

• Agronomy Guide for Field Crops - Publication 811
• Soybean Aphid
• Insects
• Soybeans
• Ontario Soybean Growers