Growers taking a "wait and see" approach to rising aphid and spider mite levels are reminded to be particularly watchful of best farm management practice recommendations available through OMAFRA to ensure they receive insurance when damage is caused by pests.

"Under production insurance, insect damage is an insured peril provided best farm management practices are followed," says Donna Bowman, Oilseed Account Lead at AGRICORP. "Using these practices will ensure that growers do not jeopardize possible claims."

Though crops are nearing the end of growth stages where they require protection, OMAF researchers warn growers to continue battling pests.

"250 aphids per plant is not the damaging threshold, but it allows you to get into your field in time before the aphids reach injuring levels," says Tracey Baute, Field Crop Entomologist, OMAFRA.  "Once your crop is in the R6 stage (when the seeds in the top pods are green and are filling the pod cavity), research has shown that you need more aphids per plant to make it worthwhile to spray."

Baute also reminds growers that harvest is quickly approaching, and days to harvest intervals need to be considered - they commonly range from 21 to 30 days.

Spider mite populations are also very high in many fields.  Telltale signs include bronze-coloured patches in fields, and leaves that are turning over and curling. Mites are smaller than the tiniest aphid, and they are spread easily by wind. 

"Mites suck on each plant cell, causing them to collapse and can actually do more injury than the soybean aphids, as entire plants can defoliate and die," says Baute. 

The threshold is four mites per leaflet.  Growers who are walking their fields and can find mites easily on plants will need to spray, as long as the crop is not already in the R6 stage or has already experienced too much injury to recover. 

"The recommended product of choice is the exact opposite as it is for aphids," says Baute.  "Cygon or Lagon are recommended, because pyrethroids like Matador do not control spider mites and can actually lead to the mite populations flaring up as it will kill off all of the beneficials feeding on them."

For more information on pest issues, visit www.soybean.on.ca and click the aphid button.  Pest issues and information about best farm management practices is also available at OMAFRA's Cropline at 1-888-449-0937.  Growers who participate in the production insurance program and have aphid or any other type of damage to their soybean crop should call AGRICORP's Customer Action Centre immediately at 1-888-247-4999.