Microbial Communities in the Developmental Stages of B and Q Biotypes of Sweetpotato Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)

Whiteflies are sap-sucking insects belonging to the hemipteran order. They are well known for their menace to agriculture, as pests and vectors, and are reported for their bacterial and Rickettsia association in B biotype. In the present investigation, culture-dependent and -independent methods were used to reveal the bacterial phylotypes associated with B and Q biotypes. Cultivable bacterial phylotypes varied with respect to growth media and biotypes. Twenty different bacterial genera, including 31 species belong to Actinobacteria, 'alpha'-, 'beta'-, 'gamma'- Proteobacteria, and Firmicutes were isolated from both the biotypes. Of the seventeen phylotypes, Bacillus, Kocuria, Moraxellla, Micrococcus, Sphingomonas and Staphylococcus were common to both B and Q biotypes. Moreover, B biotype was associated with Acinetobacter, Deinococcus, Modestobacter, Microbacterium, and Pseudomonas, whereas Q biotype was associated with Arthrobacter, Bradyrhizobium, Janibacter, Morganella, Naxibacter, and Streptomyces. Application of a culture-independent method revealed the presence of additional symbiotic bacteria: Rickettsia in B biotype and Halomonas in Q biotype, as well as primary endosymbiont in both biotypes, which could not be obtained through culture-dependent method. Presence of Staphylococcus, Micrococcus (in both B and Q biotypes), and Bacillus (only in B biotype) in all developmental stages of B. tabaci indicated their close association with host insect.