engleski

Distribution and secondary symbiont infection status of two whitefly species in Croatia

The whiteflies Bemisia tabaci and Trialeurodes vaporariorum are phloem-feeding pests that cause damage in many crops. 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 and T. vaporariorum in Croatia. Several B. tabaci and T. vaporariorum populations were collected across the country. Molecular markers were used to distinguish B and Q biotype in B. tabaci, and to test for the presence of SS in both species. Fluorescence in situ hybridization (FISH) was used to study the localization of SS. Biotype Q was the only detected in all tested B. tabaci populations. Unlike previously described Q, the Q biotype from Croatia harbored all the secondary symbionts known from B. tabaci including Hamiltonella, however, Arsenophonus and Fritschea were 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. Cardinium was the only SS found in other host tissues as well. Arsenophonus and Hamiltonella were SS detected in T. vaporariorum and they showed confined localization. Infection rates varied from 0% to 100% with presence of multiple infections in many individuals tested. Our work initiates a comprehensive study about the status of B. tabaci and T. vaporariorum in Croatia for means of better control in the future.

biotype; B. tabaci;; secondary symbionts; T. vaporariorum

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