Insects

  • Grasshoppers thrive in hot, dry conditions

    Insects

    The nominal threshold for grasshoppers in canola is 8 to 12 per square metre. The challenge with the nominal threshold is counting the grasshoppers. As soon as you walk into an area, grasshoppers take off and do not cooperate with your attempts to count them. So entomologists have come up with more practical scouting techniques.

    READ MORE

  • Map of the Week – Bertha armyworm counts

    Insects

    A few hotspots with higher bertha armyworm moth counts are showing up in Alberta, Saskatchewan and Manitoba.

    READ MORE

  • Bertha armyworm: Thresholds

    Insects

    The economic threshold is the density of larvae where the economic value of the yield lost due to feeding equals the cost of control.

    READ MORE

  • Diamondback moth larvae observed

    Insects

    Diamondback moth larvae are at noticeable levels in many canola fields in the Eastern and southern Interlake areas of Manitoba. But levels are generally below the economic threshold.

    READ MORE

  • Insect update: Bertha, diamondback and weevil counts

    Insects

    Insect trap counts are generally low across the Prairies, but bertha counts keep rising. Here are the latest provincial survey results.

    READ MORE

  • Diamondback moth parasitoid in high numbers

    Insects

    Entomologists were excited to find a known diamondback moth parasitoid, the 2mm-long Diolcogaster claritibia wasp, at very high numbers in Alberta canola fields over the past couple of weeks.

    READ MORE

  • Map of the Week – Cabbage seedpod weevil counts

    Insects

    Alberta Agriculture’s cabbage seedpod weevil survey results for 2018 are mapped. In areas with a red marker, 25% or more of samples reported are above the threshold.

    READ MORE

  • Lygus bugs: Thresholds and scouting tips

    Insects

    Lygus. Credit: Dan Johnson

    In very dry conditions: Threshold tables for lygus indicate that if canola is $12 per bushel and spray costs $8 per acre, the threshold at the early pod stage is 5 lygus adults or late instar nymphs per 10 sweeps (0.5 per sweep).

    In moist and high-yield conditions: The economic threshold is quite a bit higher. At early pod stage, 50 lygus per 10 sweeps (5 per sweep) could cause a 2 bu./ac. reduction in yield — which could be a more suitable economic threshold in this situation. At late pod stage (the last week or so before cutting), pods are too tough to penetrate.

    READ MORE

  • Insect update: The biggies plus clover cutworms and little red bugs

    Insects

    Clover cutworm damage has been confirmed in a few fields around Weyburn, Saskatchewan. They are a climbing cutworm and can be easily confused with bertha armyworm. The most distinct difference between the two species is the wide stripe along each side; it is yellowish pink on clover cutworm and yellowish orange on bertha armyworm.

    READ MORE

  • Cutworms heavy in canola on canola

    Insects

    Two CCC agronomy specialists heard this week of high cutworm damage in canola fields seeded into canola stubble. Canola on canola has many potential yield risks and we can add heavy cutworm feeding to that list.

    READ MORE

  • Map of the Week – CSPW

    Insects

    With earliest canola fields starting to flower in southern Alberta and southwest Saskatchewan, cabbage seedpod weevil scouting season begins. Here is the forecast map for 2018 based on 2017 surveys.

    READ MORE

  • Cabbage seedpod weevil: Early fields at highest risk

    Insects

    Earliest canola fields are just coming into flower in southern Alberta and southwest Saskatchewan, the highest-risk areas for cabbage seedpod weevil in Western Canada. Cabbage seedpod weevils tend to cluster in fields that are first to flower, so farmers with early fields will want to check them closely.

    READ MORE

  • Map of the Week – Bertha armyworm

    Insects

    Growing degree days across most of the Prairies have reached the threshold for adult bertha armyworm (moth) emergence from overwintering pupae. That is 7-10 days ahead of normal. Egg laying begins shortly after adult emergence and young worms emerge about a week after that. Based on 2017 results, 2018 is not expected to be a bad year, but local flare-ups can occur.

    READ MORE

  • Scouting 7 to 21 days after seeding: What to look for?

    Insects

    With warm soils, decent moisture and 1” seeding depth, emergence can occur about a week after seeding. If emergence is slow or patchy, scout to find out why. The first 21 days are critical to a successful canola crop.

    READ MORE

  • Reader question: Will plants survive flea beetle stem feeding?

    Insects

    If the tissue underneath the bite is still living, the seedling will likely survive as long as (1) the stem can still bear the weight of the cotyledons and first leaves, (2) the stem is not to subjected to more feeding, and (3) weather conditions are good for plant growth.

    READ MORE

Canola Watch