In recent years, while biodiversity efforts have become more important in urban policy, biodiversity not only has a "positive effect" on human life, but also has a "negative effect" such as an increase in vermin and pests. It has been pointed out that it is possible.However, it has not been known how this urban green space affects the types and numbers of vermin and pests.

　In the advanced research project, we conducted a comparative analysis of the number of consultations on more than 20 types of pests and beasts sent to each city, ward, town, and village in Tokyo over the past 80 years and the green area area data, and as a result, hornets, snakes, etc. For some outdoor pests such as ticks, a positive correlation was found with the green area.

　In addition, the number of consultations regarding outdoor pests has been increasing in recent years, and it has become clear that bees and other biting insects, in particular, are pests that account for about half of the total number of consultations, overtaking mice.

　Although urban green spaces are important for preserving urban biodiversity, this study shows that increasing urban green spaces may exacerbate the conflict between some pests and vermin and human life. The result was.

　On the other hand, the increase in the number of consultations regarding outdoor pests may reflect not only the increase in the number of outdoor pests, but also the result of the hypersensitive reaction of urban residents who are not accustomed to living organisms.For example, over-reporting of wasp damage and toxicity may have encouraged the hypersensitivity of urban dwellers.In order to achieve coexistence with the natural environment in cities, it is important for humans to understand the positive and negative effects of biodiversity and not to be overly sensitive.

The results of this research were published in the online scientific journal "Scientific Reports" of the "Nature" group on August 2016, 8.