Soybeans are the number one agricultural product in Brazil and Brazilian scientists are constantly on the lookout for new potential soybean pests. Recently, Brazilian scientists have identified for the first time the presence of the Soybean Stem Fly in the cerrado regions of central Brazil. The Soybean Stem Fly (Melanagromyza sojae) is native to Asia and was first identified in Brazil 32 years ago. It first appeared in the soybean fields of Rio Grande do Sul in 1983 and then it reappeared during the 2008/09 growing season and then again in 2015. In 2015, it was identified in 18 different locations in Rio Grande do Sul, Santa Catarina, and Parana, which are all in southern Brazil.
Now, researchers from the Federal University of Goias, have for the first time identified the fly as being present on volunteer soybeans in the cerrado regions of central Brazil. It is not entirely certain that the fly has been successfully established in South America, but it has also been identified in neighboring Paraguay as well.
After it was announced that the fly had been identified in Goias, the Minister of Agriculture for the state of Goias immediately ordered a survey of the area and the destruction of any soybeans found to be infected in an effort to keep it from spreading to other regions.
The fly is regarded as one of the most important pests in soybean fields in Asia including China, India, and other regions of Southeast Asia. The fly lays eggs in the soybean stem and the subsequent larva can harm the plant by robbing it of needed nutrients. The earlier the infestation occurs, the more damage that can occur. Yield losses can be in the range of 2% to 36% depending on a number of factors. The pest and its damage to the plant can be hard to detect without the aid of a microscope.
At this point, it is unclear what the potential losses may be from the soybean stem fly.
Brazilian scientists are always on the lookout for new soybean diseases or pests after soybean rust was discovered in Brazil during the 2000/01 growing season. Soybean rust is potentially the most destructive soybean diseases and if left untreated, losses can be up to 80%. It is also native to China and how it arrived in South America is uncertain. The disease has cost Brazilian farmers tens of billions of dollars in reduced yields and increased chemical costs.