Soybean gall midge was first described as a new soybean pest in Nebraska during the 2019 growing season. However, the 2023 growing season has presented several growers in the area with their first experience with the emerging pest, even as others in eastern Nebraska have been dealing with the pest for several years.
The first detection of an adult gall midge for the 2023 growing season was observed on May 26 near Mead. This is the earliest recorded date of adult emergence since the alert network started in 2019 (McMechan et al.). Typically, adults emerge in early to mid-June.
Overwintering adult soybean gall midge emerge from the previous year’s soybean fields and fly to an adjacent soybean field to lay eggs on young soybean plants. As the eggs hatch, the immature larvae feed on stem tissues underneath the epidermis, disrupting water and nutrient uptake within the plant. As the larvae grow, they will transition from a white to a bright orange color specimen.
Infested soybean plants can wilt or lodge at the feeding site and, in some cases, result in the death of the plant. Plants become susceptible to infestation around the vegetative V2 leaf stage as fissures (small cracks) develop near the base of the stem, providing an entry point for females to lay eggs.
Management has been hit-and-miss. Research studies completed by Nebraska Extension Crop Protection and Cropping Systems Specialist Dr. Justin McMechan’s lab have shown some results, but foliar-based treatments have been inconsistent between locations and years. Chemical control should only be considered if the history of gall midge has been recorded or an adjacent field has shown a history of gall midge. Gall midge is a field edge pest, so any treatments should be confined to the first 60-120 feet of the field.
Source: unl.edu
Photo Credit: istock-oticki
Categories: Nebraska, Crops, Soybeans, Livestock