AUTHOR=Dong Xiao-Ya , Tong Xiang , Ma Jing , Qiu Bai-Jing 

TITLE=Design and evaluate the performance of a mechanical system for the release of Harmonia axyridis adults

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1297182

DOI=10.3389/fpls.2024.1297182

ISSN=1664-462X

ABSTRACT=<p><italic>Harmonia axyridis</italic> (<italic>H. axyridis</italic>) is the natural enemy of many aphid species. Traditional manual release of <italic>H. axyridis</italic> adults requires substantial manpower, and release efficiency is low. Automatic mechanical devices can improve the efficiency of delivery. Based on <italic>H. axyridis</italic> adults’ morphological size, a prototype release system for <italic>H. axyridis</italic> was designed, which considered the adhesion characteristics of <italic>H. axyridis</italic> adults. According to the measured physical characteristics of <italic>H. axyridis</italic> adults, the structural parameters of the mechanical system for the release of the <italic>H. axyridis</italic> adults were determined. The relationship of the quantity of release, the impeller rotating speed, and the time for the release of <italic>H. axyridis</italic> adults were constructed. The mechanism can quantitatively adjust the number of <italic>H. axyridis</italic> adults to meet a certain <italic>H. axyridis</italic>–aphids ratio. Combining the image processing technology with the camera function of a mobile phone, the maximum cross-sectional area method was used to count the <italic>H. axyridis</italic> adults in the designated area. Results showed that the impeller rotating speed had a significant effect on the survival rate of the <italic>H. axyridis</italic> adults. When the airflow velocities were 29.5 m/s and 38.3 m/s, the survival rates of the <italic>H. axyridis</italic> adults were 93.8% and 94.5% at 4.2 rpm. The adhesion rate of the <italic>H. axyridis</italic> adults was 2.5%–4.6%. This work will provide technical support for the research of biological control.</p>