Behavioural responses of the zoophytophagous predator Nesidiocoris tenuis (Reuter) to melon and tomato plants endophytically colonized by the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin

Abstract: Entomopathogenic fungi (EF) like Beauveria bassiana are effective biological
control agents that not only act by direct contact but also provide systemic protection to plants from insect pests. Through endophytic colonization, these fungi enhance compatibility with natural predators by reducing direct contact with them. However, the impact of such
colonization on zoophytophagous predators, which feed on both prey consuming EF-colonized plants and the plants themselves, is not well understood. This study investigated the effects of systemic protection in melon and tomato plants by B. bassiana on the behavior of the zoophytophagous predator Nesidiocoris tenuis, in both infested and non-infested conditions with Bemisia tabaci nymphs.
The results revealed that N. tenuis preferred B. bassiana-colonized tomato plants when no
prey was present. However, when tomato plants were infested by B. tabaci, the predator initially chose EF-colonized plants for the first two hours, then moved to control plants. In contrast, no preference was observed for B. bassiana-colonized versus control melon plants, regardless of whether the plants were infested. This may be due to N. tenuis being more sensitive to volatile compounds from tomato plants than melon plants.
Volatile profile analysis showed significant variations between treatments, with higher
concentrations of the green leaf volatile (z)-3-hexen-1-ol, an attractant for N. tenuis, in B.
bassiana-colonized plants. These findings suggest the potential for B. bassiana to attract N.
tenuis, warranting further investigation under greenhouse and field conditions.