Effect of Feeding Stage and Density of Whiteflies on Subsequent Aphid Performance on Tobacco Plants

Bemisia tabaci Middle East-Asia Minor 1 (MEAM1) is a cosmopolitan, highly polyphagous agricultural pest, which has the capacity to displace other native insect herbivores. Here, equipped with an integrated approach, effect of developmental stages and feeding density whiteflies on Myzus persicae performance in tobacco plants are investigated. Bioassay results showed that B. nymphs, but not adult, pre-infestation significantly reduced survival fecundity M. persicae, strongest resistance was detected at medium (9–10 nymphs/cm2). Neither low nor high nymphs triggered visible aphids. However, no significant were salicylate-deficient NahG after nymph infestation. In addition distinctions, hormone quantification qPCR revealed very different effects for adult whitefly defense responses tobacco. infestation increased SA accumulation SA-responsive genes (PR-1a, PR-2a) expression suppressed JA-regulated responses. contrast, responded by slightly increasing both SA- defenses. Furthermore, higher transcription level Bt56, coding gene secretory salivary effector, recorded vs. adults, while silencing Bt56 virus-induced (VIGS) partly impaired aphid induced nymphs. These proved induction varied whiteflies: tabaci, response against aphids, threshold this resistance.