In order to elucidate the impact of secondary parasitism on a banker plant system, aphid parasitoids on banker plants were surveyed for four years in commercial greenhouses producing eggplant and sweet pepper in Kochi Prefecture, Japan. A banker plant system using Aphidius colemani was introduced into the greenhouses in November or December for the control of pest aphids from February through May. The mean rate of secondary parasitoids to total parasitoids on the alternative host aphid (Rhopalosiphum padi) on banker plants was less than 35% in the early season. In March or April, the mean rate exceeded 40%, and was more than 70% by May or June. Three main species of secondary parasitoids, Alloxysta sp. nr victrix, Dendrocerus laticeps and Syrphophagus sp., occurred throughout the season. In addition, Asaphes suspensus and Pachynouron aphidis occurred later in the season. In greenhouses where the banker plant system of aphid control failed, the increase of secondary parasitism on banker plants was sharper than in greenhouses with successful aphid control. In March and April, the higher rates of secondary parasitism on banker plants had a significant influence on the failure of aphid control.

Agriculture can be defined as a kind of the "Monodzukuri" industry (manufacturing industry) that utilizes crop photosynthesis to generate products (photosynthates). Agricultural production entirely depends on crop physioecological processes, such as photosynthesis, transpiration, translocation, and vegetative and reproductive growth, which are strongly affected by environmental conditions and farming technologies in crop fields and greenhouses. Since the beginning of agriculture, visualizing time-series data on crop physioecological processes and applying these data in everyday farm work have been impossible because of the difficulties in measuring crop physioecological processes. This invisibility of crop physioecological processes hinders not only farmers' inventive ideas but also Information and Communication Technology (ICT) and Artificial Intelligence (AI) to drive evolution and improvements in everyday farming to achieve demand-oriented crop production. Therefore, we propose an innovative concept, the "Internet of Plants (IoP)," as a regional information infrastructure for smart agriculture. This concept is driven by a cloud computing system (IoP Cloud), which is equipped with physioecological and farming support AI engines that visualize, functionalize and share highly explainable information about crop physioecological processes and farming technologies. The IoP is expected to facilitate the bottom-up evolution of agriculture, which will be driven by smart farmers empowered by IoP functions.