FA0701 (Athropod symbioses from fundamental studies
to pest and disease management; WG 1: Arthropod Symbiont
Diversity, WG 3: Host-Symbiont Interactions)
whitefly Bemisia tabaci is a cosmopolitan phloem-feeding
pest that causes damage in many crops due to direct feeding
and vectoring plant viruses. B. tabaci is species
complex of biotypes which vary greatly in their biology.
The B and Q biotypes are the most dominant and damaging
worldwide. B. tabaci harbors the obligatory bacterium
Portiera aleyrodidarum and a diverse array of secondary
symbionts (SS), including Hamiltonella, Arsenophonus,
Cardinium, Wolbachia, Rickettsia and Fritschea.
We initiated a study to survey the distribution and the
infection status by SS of B. tabaci in Croatia.
We collected several populations across the coastal part,
and used molecular markers to distinguish between B and
Q, and to test for the presence of SS. Fluorescence in
situ hybridization (FISH) was used to study the localization
of SS in B. tabaci. In all populations tested, only
Q biotype was detected. Unlike previously described Q, the
Q biotype from Croatia
harbored all the secondary symbionts known from B. tabaci
including Hamiltonella, however, Arsenophonus
was not detected in any of the populations tested.
Infection rates varied from 0 to 90%, and multiple infections
were observed in many of the individuals tested. FISH analysis
revealed a confined localization inside the bacteriome of
all symbionts, however, Rickettsia always showed
scattered phenotype. Our work initiates a comprehensive
study about the status of B. tabaci in Croatia
for means of better control in the future.