First Report of Belonolaimus longicaudatus Infecting Soybean in Indiana

Soybeans (Glycine max) are an important crop for Indiana, playing a major role in the state’s economy. In June 2021, symptomatic soybean plants were submitted to Purdue University’s Plant and Pest Diagnostic Laboratory for diagnosis. Sting nematodes were observed on the surface of the washed roots using stereo- and brightfield compound microscopy. A total of 76 sting nematodes per 100 cm³ soil were recovered from a composite soil sample. Morphological features and measurements of adult females and males of the sting nematode population were similar to those described for Belonolaimus longicaudatus. Molecular analysis confirmed the morphological identification using D2-D3 expansion segment of the 28S large subunit ribosomal DNA and internal transcribed spacer (ITS) regions. The consensus sequences were submitted to the National Center for Biotechnology Information (NCBI) database with accession numbers OM632679 and OM632681 for the D2-D3 and ITS regions, respectively. Parasitism of the sting nematode population to soybean plants was confirmed as its average population increased from 27 to 40 nematodes per pot 4 wk after inoculation under greenhouse conditions. To the best of our knowledge, this represents the first report of the sting nematode B. longicaudatus in Indiana.