Transmission of cotton seed and boll rotting bacteria by the southern green stink bug (Nezara viridula L.)

• Published in: Journal of applied microbiology 2007-08, Vol.103 (2), p.436-444
• Main Authors: Medrano, E.G, Esquivel, J.F, Bell, A.A
• Format: Article
• Language: English
• Subjects: Animals; Anti-Bacterial Agents - pharmacology; bacterial plant pathogen; Biological and medical sciences; bolls; Colony Count, Microbial; cotton; cotton pests; cottonseed; Culture Media; disease transmission; Drug Resistance, Microbial; Fundamental and applied biological sciences. Psychology; Gossypium - growth & development; Gossypium - microbiology; Gossypium hirsutum; Gram-Negative Bacterial Infections - microbiology; Gram-Negative Bacterial Infections - transmission; Heteroptera - microbiology; infection; insect vector; insect vectors; Insect Vectors - microbiology; lint cotton; Microbiology; Nezara viridula; opportunistic infections; Pantoea - genetics; Pantoea - isolation & purification; Pantoea - physiology; Pantoea agglomerans; Phaseolus vulgaris; piercing/sucking insects; Plant Diseases - microbiology; plant pathogenic bacteria; plant pests; Rifampin - pharmacology; RNA, Bacterial - genetics; RNA, Ribosomal, 16S - genetics; Seeds - growth & development; Seeds - microbiology
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/j.1365-2672.2006.03262.x

To determine the ability of the southern green stink bug (SGSB) (Nezara viridula L.) to transmit Pantoea agglomerans into cotton (Gossypium hirsutum) bolls. An SGSB laboratory colony was kept on fresh green beans. A P. agglomerans variant resistant to rifampicin (Rif) (strain Sc 1-R) was used as the opportunistic cotton pathogen. Adult insects were individually provided green beans that were sterilized and then soaked in either sterile water or in a suspension of strain Sc 1-R. Insects were individually caged with an unopened greenhouse-grown cotton boll. After 2 days, live SGSB were collected, surfaced sterilized, ground, serially diluted, and then plated on nonselective media and media amended with Rif. Exterior and interior evidence of feeding on bolls was recorded 2 weeks after exposure to insects. Seed and lint tissue were harvested, ground, serially diluted, and then plated on media with and without Rif. Bacteria were recovered on nonselective media from all insects, and from seed and lint with signs of insect feeding at concentrations ranging from 10² to 10⁹ CFU g⁻¹ tissue. The Sc 1-R strain was isolated only from insects exposed to the marked strain and from seed and lint of respective bolls showing signs of insect feeding. Evidence of insect feeding on the exterior wall of the carpel was not always apparent (47%), whereas feeding was always observed (100%) on the interior wall in association with bacterial infections of seed and lint. Nezara viridula readily ingested the opportunistic P. agglomerans strain Sc 1-R and transmitted it into unopened cotton bolls. Infections by the transmitted Sc 1-R strain caused rotting of the entire locule that masked internal carpel wounds incurred by insect feeding. Bacteria were recovered from penetration points by insects not exposed to the pathogen, but locule damage was limited to the area surrounding the feeding site (c. 3 mm). This is the first study that demonstrates the ability of SGSB to acquire and transmit plant pathogenic bacteria into cotton bolls.