Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/28/2011
Publication Date: 2/7/2011
Citation: Medrano, E.G., Toews, M.D., Bell, A.A., Esquivel, J.F. 2011. Analysis of potential cotton pathogen reservoirs based on Nezara Virdula (L.) collections from two different crop sources. Proceedings of Beltwide Cotton Conferences, January 4-7, 2011, Atlanta, Georgia. p55.
Interpretive Summary: The southern green stink bug has become a significant pest of cotton and is associated with boll damage. Previously, we showed that although stink bug feeding alone may cause some boll damage, yield loss is actually exacerbated if the insect transmits a bacterial pathogen. Upon transmission, infective bacteria spread from the stink bug feeding site resulting in rot of the entire seed and lint tissue. Here, we show that stink bugs may acquire cotton boll pathogens from corn fields. Additionally, we demonstrated that a pathogen-carrying stink bug collected from an infested cotton field may indeed vector the disease agent from boll to boll. Collectively, these data indicate that the source of the stink bug may be an important factor in whether a cotton pathogen is acquired and thus propagate infections via feeding, resulting in increased yield loss.
Technical Abstract: The southern green stink bug (Nezara viridula, L.) can cause damage to developing green cotton bolls via feeding and/or transmission of plant pathogens. Previous work showed a relationship between stink bug associated boll damage and the surrounding cultivated crops that may serve as a reservoir. Here, we collected N. viridula from a corn field juxtaposed to a cotton field to determine if corn plants were a potential pathogen reservoir. In order to determine whether N. viridula found in cotton fields were carrying and transmitting pathogens from boll to boll, a collection of SGSB was also conducted from an infested field. Insects from both collections were individually caged for five days with greenhouse grown bolls at two weeks post-anthesis that were previously pest protected. Following removal of the insects, the cages were resealed. Bolls were harvested two weeks later and analyzed for stink bug wounds and disease symptoms. Of the bolls caged with stink bugs from corn, 76% (n = 34) had signs of feeding wounds and 53% had disease symptoms. Conversely, 51% of the bolls (n = 37) caged with stink bugs collected from cotton had evidence of feeding damage with 19% showing disease. Collectively, these data indicate that the source of the stink bug may be an important factor of whether a cotton pathogen is acquired and thus propagate infections via feeding resulting in increased yield loss.