Produce a flow chart of the life cycle of Xylella fastidiosa (include relevant insect vectors) ?

Xylella fastidiosa (life cycle)
Biology and Ecology
X. fastidiosa proliferates only in xylem vessels, in roots, stems and leaves. The vessels are
ultimately blocked by bacterial aggregates and by tyloses and gums formed by the plant,
although disease induction may not be due simply to water blockage (Goodwin et al., 1988).
Pierce's disease strains of the bacterium are efficiently acquired by vector insects, with no latent
period, and persist in infective adult insects indefinitely (Severin, 1949). In tests made during the
1940s in California, USA, 75 of 100 tested plant species proved to be hosts from which vectors
could acquire the pathogen by feeding (Freitag, 1951). Additional studies with culturing and
targeted gene amplification (PCR) of X. fastidiosa revealed additional symptomless hosts
(Purcell and Saunders, 1999b; Costa et al., 2004; Wistrom and Purcell, 2005). Most of these
hosts have only very mild (slight stunting) or no symptoms when infected.
Winter climate is a key factor in delimiting the areas where X. fastidiosa can persist from one
season to the next. Pierce's disease and phony disease only occur in areas with a mild winter,
presumably in relation to survival of the bacterium in dormant plants (Purcell, 1980a).
Experimental cold therapy of diseased grapevines suggests that freezing temperatures can
eliminate the bacterium directly from plants (Purcell, 1980a). Wet winters promote survival of
high vector populations and favour disease spread in regions with dry summers. In temperate
climates with regular freezing winter temperatures, infections of X. fastidiosa established in
grapevines during the early growing season are most likely to persist until the following year
(Purcell, 1981; Feil et al., 2003a). In California, USA, there is no evidence of vine to vine spread
of chronic infections, probably because when bacteria first appear in new foliage (Smart et al.
1998), the chances of establishing infections that will survive the subsequent winter are small.
For this reason, vectors that...