Integrated Crop Management News

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Soybean Gall Midge Adults Now Emerging

June 8, 2023
Soybean gall midge adults.

Two male adult soybean gall midges were found in emergence cages at the Northwest Research and Demonstration Farm near Sutherland on June 6. This is about one week earlier than previous first captures in Iowa since we started monitoring emergence in 2019. The first Midwest report of soybean gall midge emergence in 2023 was May 31 near Mead, Nebraska. You can keep up with soybean gall midge emergence at

Stalk Borers are Migrating to Corn

June 6, 2023
Degree days accumulated for stalk borer in Iowa.

Stalk borer is an occasional pest of corn, but it can be persistent in some fields, especially those fields near perennial grasses that serve as overwintering sites (fence rows, terraces, and waterways are typical sources). Tracking degree days is a useful way to estimate when common stalk borer larvae begin moving into cornfields from their overwintering hosts. Foliar insecticide applications are only effective when larvae are migrating and exposed to the insecticide. Start scouting corn for larvae when 1,300-1,400 degree days (base 41°F) have accumulated.

Return Program Available for Certain Chlorpyrifos Products

May 11, 2023

In late April, the Environmental Protection Agency (EPA) authorized product registrants, Corteva Agriscience and Adama US, to proceed with accepting return shipments of certain cancelled products containing the active ingredient, chlorpyrifos.

Online Tool Helps Farmers Harvest Alfalfa at the Right Time

May 10, 2023
Alfalfa measurement.

Alfalfa growth has been slow this spring due to cooler than normal weather. This is a good reminder that using a calendar date to determine when to harvest the first crop of alfalfa may not be the best method. A better way to make harvest decisions is the PEAQ method (Predictive Equations for Alfalfa Quality) which takes several factors into account to roughly estimate the relative feed value (RFV) of standing alfalfa in the field.

Scout for Black Cutworm in Corn Early this Year

May 8, 2023
Black cutworm cutting dates.

Black cutworm (BCW) is a migratory pest that arrives in Iowa with spring storms each year. Black cutworm moths lay eggs in and near crop fields, and larvae can feed on leaves or cut corn seedlings. Larvae must attain a certain size (4th instar) to be large enough to cut corn plants, and cutting can occur until plants reach the V5 stage. Black cutworm is sporadic and unpredictable, making it essential to scout to determine whether BCW larvae are present in a field and if management is required.

Soybean Aphid Egg Hatch is Complete

May 4, 2023
Accumulated growing degree days map.

Iowa’s most significant soybean insect pest, the soybean aphid, alternates between two hosts to complete its development. The primary host of soybean aphid is buckthorn, an invasive shrub often found in hedgerows and roadside ditches, and its secondary host is soybean. For most of the year, soybean aphids exist as cold-hardy eggs on buckthorn branches near leaf buds. For many aphids that overwinter as an egg, hatching happens when the host resumes spring growth. If eggs hatch too soon, aphids can suffer mortality from starvation because they feed on phloem from actively growing tissue.

Variable Overwintering Success for Bean Leaf Beetles this Year

April 26, 2023

Bean leaf beetle adults (Photo 1) are susceptible to cold weather, and most will die if exposed to air temperatures below 14°F. However, they avoid harsh temperatures by burrowing under plant debris and loose soil. Each spring, adult beetles emerge from their overwintering habitat and migrate to available hosts, such as alfalfa, tick trefoil, and various clovers. As the season progresses, bean leaf beetles move to preferred hosts, like soybean.

Establishing a New Stand of Alfalfa

April 14, 2023
corregated roller in action.

Spring has arrived and many fields are full of activity. April is a great time to seed alfalfa whenever the soil is fit. Shallow-seeded forages will germinate and grow very quickly with adequate soil moisture and just a few warm days. The key to getting a great alfalfa stand is proper soil preparation and timing of the seeding.