|Sengoda, Venkatesan -|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 8, 2011
Publication Date: December 20, 2011
Citation: Buchman, J.L., Sengoda, V.G., Munyaneza, J.E. 2011. Vector transmission efficiency of liberibacter by Bactericera cockerelli (Hemiptera: triozidae) in zebra chip potato disease: effects of psyllid life stage and inoculation access period. Journal of Economic Entomology. 104(5):1486-1495. Interpretive Summary: Zebra chip, an important disease of potato, is caused by a bacterial pathogen that is vectored by the potato psyllid. Researchers at USDA-ARS Wapato, WA evaluated how effectively and rapidly this insect pest transmits the disease. It was discovered that psyllid adults were more efficient in transmitting zebra chip to potato than their immature stages. In addition, it was determined that a psyllid adult was capable of transmitting the disease when feeding for as little as six hours. This information will help potato producers minimize damage caused by this disease by particularly selecting and applying fast acting insecticides targeted against the potato psyllid adults.
Technical Abstract: The successful transmission of plant pathogens reliant on insect vectors is dependent on the vector inoculation efficiency and how rapidly the insect can effectively transmit the disease pathogen to the host. The potato psyllid, Bactericera cockerelli (Šulc), has recently been found to transmit “Candidatus Liberibacter solanacearum”, a bacterium associated with zebra chip (ZC), an emerging and economically important disease of potato in some parts of the world. Currently, little is known about the epidemiology of ZC and its vector’s inoculation capabilities. Studies were conducted in the field and laboratory to 1) assess the transmission potential of potato psyllid nymphs and adults, 2) determine if psyllid inoculation access period affected ZC incidence, severity and potato yield, and 3) determine how fast the psyllid can transmit liberibacter to potato and cause development of ZC. Results showed that adult potato psyllids were highly efficient vectors of liberibacter that causes ZC and that nymphs were less efficient than adults at transmitting this bacterium. It was also determined that inoculation access period had little influence on overall ZC disease incidence, severity, and resulting yield loss. Moreover, results showed that exposure of a plant to 20 adult potato psyllids for a period as short as one hour resulted in ZC symptom development. Furthermore, it was shown that a single adult potato psyllid was capable of inoculating liberibacter to potato within a period as short as six hours, thereby inducing development of ZC. This information will help in developing effective management strategies for this serious potato disease.