D3225: Soybean gall midge: understanding adult emergence through artificial rainfall and physical barriers

The soybean gall midge (SGM), Resseliella maxima Gagné is a recently described pest that has caused significant yield losses within the Midwest. Adult SGM will oviposit their eggs onto natural occurring fissures at the base of soybean plants. After feeding larvae fall to the soil where they pupate and emerge as adults with an estimated 2-3 generations per year. A larval dispersion study in 2021 found preliminary results that indicate larvae may be able to move a distance of 10 feet from their source plant. As a result, a study is being conducted to restrict larval movement through placement of an impassable barrier with and without the addition of rainfall. The objectives of this study is to identify any effects of having an enclosed space on timing and emergence and to determine the effects of artificial water applications on adult emergence under field conditions. Wooden frames measuring 40 cm wide, 76 cm long, and 20 cm in height will be placed in the field after larvae are found on soybean plants. Water will be applied to half of the frames as well as an open area nearby. Emergence cages of the same dimensions will be placed the frames and adjacent open areas. All treatments will be monitored for the timing and abundance of adults. The results could increase the understanding of environmental interactions and the duration of development in the soil and the timings of