Tag Archives: scouting

Scouting for onion thrips

Onion thrips (Thrips tabaci) feed on more than just onions; they also feed on cabbage, leaf lettuce, a variety of other vegetables and fruits, field crops, and many weed species. Thrips are unique from other insects as they have rasping-sucking mouthparts that allow them to scratch the cell walls of leaves, suck up the cell contents including the chlorophyll, and leave behind a shiny, translucent trail on the leaf. A single female can produce Continue reading Scouting for onion thrips

Downy Mildew Report for the week of June 12, 2017

By Cheryl Trueman, University of Guelph – Ridgetown Campus

Scouting for downy mildew in pickling cucumber fields in Norfolk County began on June 13 (3 of 5 sites) and will begin in Kent County on June 19.You can track sightings of downy mildew in North America on the IPMpipe Cucurbit Downy Mildew website.
More information:
2017 Downy Mildew Control Strategy for Cucumber Crops
2016 Fungicide efficacy and fungicide program results.


Cabbage Maggot; An old pest with limited options

The cabbage maggot (Delia radicum) is the larvae stage of the cabbage root fly which can cause severe damage to all Brassica crops. The adult cabbage maggot is a fly that is about half the size of a house fly and is grey in colour.

In the early spring, cabbage maggot flies emerge from the soil and the females lay small, white eggs ~2-10 cm below the soil line. Depending upon the temperature, eggs hatch 3-7 days later as larvae that immediately start boring Continue reading Cabbage Maggot; An old pest with limited options

Lassoing Loopers: why you NEED to care about caterpillar control

Adapted from ONfloriculture by Sarah Jandricic, Greenhouse Floriculture IPM Specialist, OMAFRA

This article was originally written for the floriculture industry, but I have adapted it, with permission, as an awareness article for vegetable growers. — Janice

Know which looper species this is? Are you SURE? If not, keep reading, as some species could get your shipments detained at the border. Photo: Steve Hatch, Bugwood.org.
Know which looper species this is? Are you SURE? If not, keep reading, as some species could get your shipments detained at the border. Photo: Steve Hatch, Bugwood.org.

At this point, most field vegetable growers are focussed on getting the crops in and juggling early season field activities. If you’re thinking about caterpillars right now, it would probably be black cutworm.  But recent alerts put out by the United States Department of Agriculture (USDA), bring a new emphasis to caterpillar control.  Read on to understand what’s happening, and — for those with US customers — how to control occasional pests like cabbage looper, and avoid potential issues at the border. Continue reading Lassoing Loopers: why you NEED to care about caterpillar control

Preventing Yield Loss from Flea Beetles

Flea beetles are a common crop pest of crucifers in Ontario and overwinter as adults near the soil surface in debris and stubble from the previous crop. They typically become active with the first extended period of warm weather in the early spring as the leaf litter begins to thaw. The beetles feed on weeds throughout the field and have the ability to fly on calm days and will attack brassica seedlings as they emerge or transplants as they are planted.

Females will begin laying eggs in soil for about 30 days. Flea beetle larvae will hatch from eggs 12 days later and feed on the root hairs and taproots of seedlings. Left unchecked, adults will feed on leaves of transplants and the larvae will burrowing into the plant near the juncture of the root and stem. Continue reading Preventing Yield Loss from Flea Beetles

Pepper weevil in field peppers

Pepper weevil adult on pepper budPepper weevil is not usually given much thought in field peppers in Ontario, but from time to time it might be found in a localized area. It is a pest to be aware of, because there are very few external signs that indicate there is larvae present inside the pepper fruit.

Pepper weevil is unlikely to survive typical winter conditions in Ontario unless in a protected area, so risk factors for the pest include proximity to pepper greenhouses/packing sheds or culls/waste plant material from these operations or from areas with warm winters, like the southern US. If you are in a risk area, consider field scouting and pheromone traps. Continue reading Pepper weevil in field peppers

Which worms are which?

I’m just terrible at recognizing people that I don’t know very well — coming up with their name or even where I know them from (as I think many in the vegetable industry have noticed). So embarrassing — I’m definitely in the wrong line of work. And then I also have to try to be able to identify all kinds of crop pests, too, although that’s usually not as hard for me. But I do find it challenging to remember which worm is which sometimes, so here’s a cheat sheet I use. Maybe it will help you, too. They are listed in approximate order of appearance.

Black Cutworm
Figure 1: Black cutworm

Black cutworm (Agrotis ipsilon)

Distinguishing features:

  • Colour ranges from gray to almost black
  • Indistinct narrow stripe along the centre of the back
  • Granular skin texture (see closeup in Purdue Pest & Crop article)
  • Dark-coloured head
  • Four pairs of abdominal prolegs, plus one pair at back end

Time of the year:

  • early May – mid-June

Continue reading Which worms are which?