Benefits of intraguild interactions between zoophytophagous predators and of bottom-up effects of fertilisation for sustainable management of tomato pests

Effective management of tomato pests such as Bemisia tabaci and Tuta absoluta requires the integration of more sustainable control methods. Applying integrated pest management (IPM) approaches using combinations of biocontrol agents with agronomic practices such as the modulation of fertilisation offers opportunities toward more efficient pest control, all the more so since the underlying bottom-up and top-down regulations are interdependent. We investigated the relative influence of the bottom-up effects of reduced fertilisation (by 47%) and the use of the mirid predators Dyciphus errans or Macrolophus pygmaeus in combination with Nesidiocoris tenuis on the control of B. tabaci and T. absoluta. Densities of B. tabaci and T. absoluta population decreased more rapidly when fertilisation was reduced. The presence of D. errans caused reduction in N. tenuis densities and in the number of necrotic rings caused by N. tenuis. The negative effects of bottom-up forces triggered by reduced fertilisation on B. tabaci, T. absoluta and N. tenuis populations and damage were greater in the presence of D. errans. Our study shows that interactions between predators and fertilisation management are important in agro-ecosystems and should be considered in the development of sustainable IPM strategies.