The meadow spittlebug Philaenus spumarius is the primary vector of Xylella fastidiosa in Europe. In this paper, researchers gathered data on the insect’s feeding behavior through DC EPG (electrical penetration graph)-assisted transmission tests and comparative observations of infective versus non-infective vectors on healthy olive plants.
The results give the first insights into the transmission dynamics of the bacterium Xylella fastidiosa by P. spumarius.
Researchers observed that bacterial cells binding to P. spumarius’ foregut occurred at a very low rate and in a time as short as 15 min spent by the insect in xylem ingestion or activities interspersed with xylem ingestion (interruption during ingestion and resting). The insect inoculation of bacterial cells into the xylem was exclusively associated with an early and occasional behavior (lasting 2 to 7 min after the onset of the first probe)
Infective spittlebugs compared to non-infective ones exhibited: longer non-probing and shorter xylem ingestion, longer duration of single non-probing events, fewer sustained ingestions (ingestion longer than 10 min) and interruptions of xylem activity, longer time required to perform the first probe.
These observations suggest difficulties in the feeding of infective P. spumarius, probably caused by the presence of X. fastidiosa within the foregut. Overall, the data indicate that it is likely that a short time—few minutes—is required for X. fastidiosa transmission by P. spumarius. Thus, researchers suggest that vector control strategies should aim at preventing spittlebug access to the host plant.
DOI: https://doi.org/10.1007/s10340-020-01236-4 | via Springer