Gross morphology of diseased tissues in Nezara viridula (Hemiptera: Pentatomidae) and molecular characterization of an associated microsporidian

Authors: Rivers, Adam; Grodowitz, Michael; Miles, Godfrey; Allen, Margaret - Meg; ELLIOTT, BRAD - Former ARS Employee; Weaver, Mark; BON, MARIE-CLAUDE - European Biological Control Laboratory (EBCL); Rojas, Maria - Guadalupe; Morales Ramos, Juan

Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/31/2022
Publication Date: 3/18/2022
Citation: Rivers, A.R., Grodowitz, M.J., Miles, G.P., Allen, M.L., Elliott, B., Weaver, M.A., Bon, M., Rojas, M.G., Morales Ramos, J.A. 2022. Gross morphology of diseased tissues in Nezara viridula (Hemiptera: Pentatomidae) and molecular characterization of an associated microsporidian. Journal of Insect Science. 22(2):4. https://doi.org/10.1093/jisesa/ieac013.
DOI: https://doi.org/10.1093/jisesa/ieac013

Interpretive Summary: Diseases of insects can be used to control pests of crops and livestock. Dissection of specimens of the southern green stink bug revealed black spots suspected of being diseased tissue. Similar spots in other stink bugs were recently described as a fungal pathogen, Nosema maddoxi. Samples of diseased and healthy tissues were analyzed and diseased tissues consistently contained high levels of Nosema maddoxi. This report supports the conclusion that Nosema maddoxi infects many stink bugs, and may be a pathogen that is ecologically important and might be exploited as a pest control treatment.

Technical Abstract: Nezara viridula (L.) (Hemiptera: Pentatomidae), commonly known in the U.S. as the southern green stink bug (SGSB), is a cosmopolitan, highly polyphagous feeder that causes severe damage to a wide range of agronomically important crops such as fruit, vegetable, grain, tobacco, and cotton, throughout much of the United States, and is a global pest of considerable ecological, agricultural, and economical interest. During dissection of female N. viridula, conspicuous black and brown spots or lesions were observed on various internal organs. To determine the cause of these spots or lesions, tissues of fat body, spermatheca, ovaries, and ovulated eggs were collected from healthy and infected individuals. The gross morphology of the spots was characterized, and the microorganisms associated with the infection were provisionally identified by amplicon sequencing of the V4 region of the small subunit rRNA gene. The presence of a microsporidian pathogen Nosema maddoxi which has been observed on other species of stink bug was evidenced for the first time. The characterization of the gross morphology of this associated microsporidian may enable more rapid determination of microsporidia infection in stink bug colonies and field populations.