Corn earworm pressure often increases as we head into September. With turbulent weather patterns originating in the Gulf of Mexico, flights of airborne moths are generally quite high. As the tradewinds mix with the cooler air of the great lakes, these high populations are dropped into Southern Ontario. Any sweet corn at the green silk stage is highly susceptible to corn earworm infestation.
For earworm control, cover green silks with an insecticide such as Coragen or Voliam Express. Avoid insecticides from the pyrethroid family. Corn earworm are known to be resistant to the pyrethroids. Lannate TNG is a good rotational partner for Coragen and Voliam Express.
Asparagus beetle activity is on the rise. The adult beetles hide in soil cracks or underneath residue during the heat of the day. Egg laying is often the most obvious sign of their activity. The presence of eggs on the harvest spears, may affect marketability. On young fern, heavy amounts of larval feeding has a negative impact on growth and development.
As harvest concludes, scout plantings regularly as the spears begin to elongate and develop a full canopy of fern. Spray thresholds are as follows:
Eggs: 2 /10 spears with eggs Larvae: 50% of plants with larvae OR 10% Defoliation Adults: 5-10% of plants infested
If controls are required during the harvest season, play close attention to the pre-harvest intervals. Products with a 24-hr pre-harvest interval include: malathion (Malathion 85E), cypermethrin (Mako, Upside 2.5 EC), and acetamiprid (Assail 70WP).
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
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→
Sprayer operators recognize the importance of matching their sprayer settings to the crop to optimize efficacy. For example, spraying a protective fungicide in field tomato should require a different approach from spraying a locally systemic insecticide in staked peppers. Knowing this, many operators make ad hoc changes and then wait to “see if it worked”. A process is required that empowers the operator to make systematic changes to their program and assess coverage immediately. Continue reading How to assess spray coverage in vegetable crops→
Pepper weevil is a pest that is likely unfamiliar to most Ontario field pepper growers. It has been found in Ontario previously (https://onvegetables.com/2010/06/01/pepper-weevil/) and there have been reports of its presence in 2016. As it can be a very serious pest of peppers, it is advisable for all pepper growers to monitor for the pest in their crop. Pepper weevil can affect both field and greenhouse pepper crops, but this article will focus on scouting and management in the field.
Adults are small weevils, 2-3.5 mm in length (Figures 1 and 2).
Difficult to detect the pepper weevil adults through crop scouting if it is present at low levels
(unless using pheromone traps).
Eggs are laid in the fruit wall, leaving a dimpled scar (Figure 3).
Larvae grow and develop inside the pepper fruit; pupae form inside the fruit (Figure 4).
New adults create an exit hole and leave the fruit.
Laura Stortz, OMAFRA / University of Guelph USEL student; Denise Beaton, OMAFRA Crop Protection Program Lead; Hannah Fraser, OMAFRA Entomology Program Lead (Hort)
The Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) is collecting Cabbage Maggot larvae and pupae this summer as part of a national survey. We need grower cooperators for this survey! The goals of this survey are:
To better understand the fly species responsible for damage to Brassicae vegetable crops.
The larval stage of the Delia radicum fly species is thought to be the main culprit attacking Brassicae vegetable crops; however, there could be other species at play.
Test for pesticide resistance in the fly species.
Cabbage maggot is showing resistance to Lorsban (chlorpyrifos). This study’s results could lead to more efficient use of insecticides and support research on alternative control options.