posted on 2023-12-19, 14:31authored byJesus F. Esquivel, Enrique G. Medrano
<p>Southern green stink bug [<em>Nezara viridula</em> (L.)] adults and other pentatomid pests can transmit pathogens (e.g., the bacterium <em>Pantoea agglomerans</em>) that cause disease in cotton (<em>Gossypium hirsutum</em> L.) and other high-value cash crops worldwide. First instars of <em>N. viridula</em> were recently shown to ingest <em>P. agglomerans</em> strain Sc1R with rifampicin-resistance, and to retain the pathogen to the 2nd instar. The objective of this study was to determine the acquisition of <em>P. agglomerans</em> Sc1R by early instars of <em>N. viridula</em> and determine persistence of <em>P. agglomerans</em> Sc1R across subsequent stadia. In three trials, early instars (1st and 2nd) were exposed to <em>P. agglomerans</em> Sc1R and subsequently maintained to adulthood; cohorts were sampled at 3rd and 5th instars, as well as adults. In every trial, <em>P. agglomerans</em> Sc1R was detected in all stadia, including adults, but significantly higher frequencies of infection than expected were observed at the initial stage of infection (either 1st or 2nd instar). Higher densities of <em>P. agglomerans</em> Sc1R were detected in 1st and 2nd instars, and lower densities were observed in subsequent stadia. Densities of innate bacterial flora were generally lower when the initial stage of exposure was at 1st instar than when the initial stage of exposure was at the 2nd instar. Overall, half of the adults possessed <em>P. agglomerans</em> Sc1R. These findings demonstrated that <em>N. viridula</em> nymphs can acquire <em>P. agglomerans</em> Sc1R and retain the pathogen to adulthood. Potential avenues of research to further elucidate the implications of nymphs harboring pathogens to adulthood are discussed. </p><div><br>Resources in this dataset:</div><br><ul><li><p>Resource Title: Raw data for interstadial retention of Pantoea agglomerans Sc1R by southern green stink bug stadia.</p> <p>File Name: Interstadial pathogen retention_final data.csv</p><p>Resource Description: Raw data for Retention of Sc1R across interstadial molts of the southern green stink bug, 2019; CFU, colony-forming units; CFUs_count, number of colony-forming units; LBA, Luria Bertani agar; LBA_Rif, Luria Bertani agar amended with rifampicin; Sc1R, <em>Pantoea agglomerans</em> Sc1R</p></li><br><li><p>Resource Title: Summary tables of LSMeans and back-transformed means for densities of Pantoea agglomerans and general bacteria across southern green stink bug stadia.</p> <p>File Name: Log-LSMeans and back_transformed means for Pantoea agglomerans Sc1R densities in southern green stink bug stadia.csv</p><p>Resource Description: Summary tables of densities of <em>P. agglomerans</em> Sc1R and general bacteria across stadia of the southern green stink bug.</p></li></ul><p></p>
Pathogen retention data can and will be used for a continued battery of tests elucidating the potential for southern green stink bugs to transmit disease pathogens of cotton. Adults were previously shown to conclusively transmit P. agglomerans and the current findings indicate immature stages could also serve as potential vectors. Additionally, the vector potential by nymphs could feasibly affect pest management practices where more stringent thresholds may be implemented.
Use limitations
The work was conducted in the laboratory. Due to the infective nature of the pathogen, researchers currently believe that it is inadvisable to conduct field trials. Nonetheless, the proof-of-concept in using laboratory studies indicates that the immature stages can acquire and retain P. agglomerans.
The laboratory work was conducted at the USDA, ARS, Insect Control & Cotton Disease Research Unit in College Station, TX, USA. However, the southern green stink bug is a world-wide cosmopolitan insect pest of crops.
Esquivel, Jesus F.; Medrano, Enrique G. (2020). Data from: Retention of Pantoea agglomerans Sc1R across stadia of the southern green stink bug, Nezara viridula (L.) (Hemiptera: Pentatomidae). Ag Data Commons. https://doi.org/10.15482/USDA.ADC/1520160