General trends and strategies for the development of new pesticides are summarized. From 2015 to 2025, 156 chemical pesticides were launched or are under development: 47 fungicides, 54 insecticides/acaricides, 9 nematicides, and 46 herbicides. Most are safe to humans and environmentally friendly. The most developed fungicides are succinate dehydrogenase inhibitors, quinone outside inhibitors, quinone inside inhibitors, and demethylation inhibitors. The general trend of insecticide development is in the progress of four major classes of insecticides: nicotinic insecticides, diamide insecticides, GABA-gated chloride channel allosteric modulators, and insect behavior or growth regulators. Due to the development of resistance to fungicides and insecticides with existing modes of action, many compounds possessing various novel modes of action have been developed. Peptide pesticides and RNAi-based insecticides have been put into practical use. Although no herbicides with novel modes of action appeared for approximately 30 years before 2018, since then eight herbicides with five novel modes of action have emerged, including those for existing herbicides. The development of useful acaricides and nematicides is also progressing.

Using the fugacity model InPestCFD, we predicted the indoor behavior of an active substance in an aerosol intended for controlling flies and mosquitoes under various conditions and conducted a comprehensive risk assessment. In predicting behavior, we examined the impact of spraying methods, room air exchange rates, position of an air inlet, and location of a bed, revealing spatiotemporal behaviors not observed previously. For the risk assessment, we predicted the exposure levels for adults and children based on different scenarios from the predicted concentrations and compared them with the acceptable levels of the active substance. Comparison of the obtained results with the results of risk assessment currently conducted in Japan and the United States revealed that current guidelines are considerably conservative in the United States and sufficiently conservative in Japan.

In this study, we report the results of sensitivity tests to succinate dehydrogenase inhibitor (SDHI) fungicides performed on isolates of cucumber Corynespora leaf spot, powdery mildew, and tomato leaf mold pathogens collected in Japan. Isofetamid and fluopyram showed strong activity against boscalid-resistant isolates of Corynespora cassiicola from Tokushima Prefecture in in vitro antifungal assays and in vivo pot experiments. Isofetamid and fluopyram also showed comparable efficacy against boscalid- and penthiopyrad-resistant isolate of Podosphaera xanthii collected in Saga Prefecture using a leaf disc assay. No change was detected in the amino acid sequence of sdhB in the causal pathogen. In addition, during in vitro antifungal tests, isofetamid demonstrated high activity against Fulvia fulva isolates resistant to boscalid, penthiopyrad, and fluopyram obtained in Gifu Prefecture. Collectively, these results indicated that isofetamid maintained similar efficacy against isolates resistant to other SDHIs as against sensitive isolates of these pathogens.

For this study, first, the composition of phytoseiid mite species was examined at vineyards in Shimane Prefecture, western Japan, in 2023 and 2024 using quantitative sequencing (QS) and nucleotide sequencing. Amblyseius eharai and Amblyseius andersoni were the most dominant species. Then, the proportion of sodium channel mutations (M918L and L925V/M) involved in pyrethroid resistance was examined using another QS and nucleotide sequencing. Results revealed wide distributions of both mutations in A. eharai and the former mutation in A. andersoni. Results also revealed the presence of M918L in Neoseiulus barkeri and Neoseiulus californicus, but not in Euseius sojaensis. Genotyping for the other mutation sites using the collected phytoseiid mites revealed that all A. eharai and A. andersoni individuals had S1539T, as did some N. californicus individuals. These results suggest that phytoseiid mite species, with the exception of E. sojaensis, have reduced sensitivity to pyrethroids in vineyards in Shimane Prefecture.

The most harmful weed in African agriculture is the root parasitic witchweed Striga hermonthica, of the family Orobanchaceae, which parasitizes staple food crops. Some broomrapes (Orobanche spp.) and branched broomrapes (Phelipanche spp.) also cause significant loss of leguminous crops and vegetables worldwide. Therefore, the control of root parasitic weeds is an agricultural issue worldwide. Because root parasitic weeds are obligate, reaching the host roots following germination through their radicle elongation is required to complete their life cycles. Conversely, inhibiting germination and radicle elongation may be an effective strategy for controlling root parasitic weeds. We identified a characteristic storage carbohydrate, planteose, in root parasitic plants and examined its metabolism, which may serve as a target for controlling root parasitic weeds. Here, our study of the germination process in the root parasitic weeds is reviewed, and the potential of germination metabolic inhibitors as control agents for root parasitic weeds is discussed.

Plants that live a life fixed to the ground cannot escape from various pathogens and must deal with them. To effectively defend against pathogen infection, plants have various resistance mechanisms, which are in a trade-off relationship with growth. In addition to these disease resistance mechanisms, plants have a system called priming that enhances resistance mechanisms but does not affect growth. Analysis of immune priming induced by mycorrhizal symbiosis in tomato revealed that priming is effective against multiple defense signals mediated by salicylic acid (SA) and jasmonic acid signals and against both pathogenic and non-pathogenic bacteria. In Arabidopsis, strigolactone signaling-induced priming was shown to enhance ethylene signaling and camalexin synthesis in addition to SA signaling. These findings are expected to lead to more effective use of priming to protect plants in the future.