Improved decision making of Nezara viridula in greenhouse crops based on citizen science data

Abstract: The southern green stink bug Nezara viridula (Heteroptera: Pentatomidae) is a major pest in greenhouse pepper crops in Northwestern Europe. Biological control of this species is difficult. First tests with the commercially available egg parasitoid Trissolcus basalis (Hymenoptera: Scelionidae) show promise but appear to be expensive. Most growers rely on pesticides for the management of N. viridula, which often results in a collapse of the IPM strategy and the occurrence of secondary pest problems. Thus, the IPM strategy for N. viridula needs urgent improvement to meet the growers’ needs. Timely implementation of actions is crucial for the success of the IPM strategy.
In this study, we have built a predictive, phenological, stage-structered, mathematical day
degree model based on citizen science data (www.waarnemingen.be; www.waarnemingen.nl).
This dataset is fed by citizens uploading observations of wildlife. In total, we have more than
6000 observations, resulting in four years (2019-2022) of detailed phenological data. Every
observation is complemented by a picture, which allowed the determination of the
developmental stage of each individual insect. Biological information was obtained from
literature and additional laboratory trials. This resulted in a validated phenological day degree model. This model not only predicts the first observation of each developmental stage of N. viridula but predicts the full population dynamics of all generations as well for a given year. This study highlights the importance of greenhouse model simulations in providing useful insights to accurately time IPM actions and eventually improve the control of N. viridula. Final validation trials are planned in 2023.