Effects of Rifampicin and Tetracycline on Endosymbiont Prevalence and Life Table Parameters in Bemisia tabaci ( MEAM1 )

ABSTRACT The whitefly Bemisia tabaci (MEAM1) is an important agricultural pest whose fitness and population dynamics are linked to its bacterial endosymbionts. Understanding how antibiotic exposure disrupts these symbiotic associations and induces transgenerational effects on host performance is essential for elucidating symbiont‐mediated mechanisms underlying insect fitness. In this study, we examined the effects of rifampicin and tetracycline on life table parameters and the prevalence of key endosymbionts in B. tabaci across two generations. Whiteflies of the F 0 generation were fed antibiotic‐supplemented diets and biological parameters and symbiont infection rates were subsequently assessed in both F 0 adults and their F 1 offspring. Both antibiotics prolonged immature development and increased mortality in the F 1 generation. However, rifampicin induced a pronounced transgenerational effect, with F 1 total fecundity declining to 10.15 eggs per female compared with 105.35 eggs in the control. This reduction was accompanied by a severe demographic decline, as the net reproductive rate (R 0 ) decreased from 49.09 to 3.63 and the intrinsic rate of increase ( r m ) from 0.133 to 0.038, resulting in an increase in population doubling time (DT) from 5.18 to 18.00 days. Molecular analyses showed that Portiera detection frequency decreased to 19% in the rifampicin‐derived F 1 generation. Tetracycline, whereas, had a weaker effect on Portiera and resulted in numerically lower Rickettsia detection frequencies. Collectively, these findings suggest that transgenerational reduction in Portiera detection frequency is associated with reduced fitness and severe demographic suppression in B. tabaci , highlighting the important role of this obligate symbiont in host performance.