Monitoring activity and sampling of potato psyllid, Bactericera cockerelli (Hemiptera: Triozidae), adults in potato fields in the Lower Rio Grande Valley of Texas

Experiments were conducted at Weslaco, Texas during the 2012-2013 potato growing season to monitor activity of adult potato psyllids, Bactericera cockerelli (Sulc), on potato (Solanum tuberosum) plants. As a direct pest, B.cockerelli causes psyllid yellows disease and is also a vector of “Candidatus Liberibacter solanacearum” (Lso), a phloem-limited, gram-negative bacterium that is associated with potato zebra chip disease. It is known that a single adult B.cockerelli is capable of transmitting Lso within 6h of feeding. Although several studies have been conducted on the transmission efficiency of B.cockerelli, additional information is needed to determine its significance for field applications. Therefore, adult activity was monitored in potato fields by marking selected plants and counting B. cockerelli on the plants at three different times of the day (8:00 am, 12:00 noon and 4:00 pm) from 3^rd March to 4^th April 2013. Noon counts were highest, followed by evening, and morning counts were lowest. In a separate study, potato plants were planted singly as well as in groups of four and 16 plants to study the preference of adult B.cockerelli for individual or groups of plants. An insect vacuum aspirator was used for sampling the adults. Abundance of B. cockerelli was significantly higher in the largest plot size. However, on a per plant basis, with each 4-fold increase in plant density, B.cockerelli abundance decreased by one-half. These results may have important implications for designing trap crop areas.