AUTHOR=Sulg Silva , Kaasik Riina , Kallavus Triin , Veromann Eve 

TITLE=Toxicity of essential oils on cabbage seedpod weevil (Ceutorhynchus obstrictus) and a model parasitoid (Nasonia vitripennis)

JOURNAL=Frontiers in Agronomy

VOLUME=5

YEAR=2023

URL=https://www.frontiersin.org/journals/agronomy/articles/10.3389/fagro.2023.1107201

DOI=10.3389/fagro.2023.1107201

ISSN=2673-3218

ABSTRACT=<p>Plant essential oils are being increasingly studied as a potential environmentally friendly alternative to synthetic insecticides. The insecticidal efficacy of essential oils on the cabbage seedpod weevil (<italic>Ceutorhynchus obstrictus</italic>), an important oilseed rape pest, has not been previously tested. We examined the impact of six essential oils on <italic>C</italic>. <italic>obstrictus via</italic> contact with dry residues on leaf and flower surfaces. We also examined the effect of these essential oils on a model non-target parasitoid wasp, <italic>Nasonia vitripennis</italic>. Exposure to dry residues of cumin (<italic>Cuminum cyminum</italic>) and cinnamon (<italic>Cinnamomum verum</italic>) essential oils (applied to oilseed rape leaves) resulted in significant loss of mortality and immobility in <italic>C</italic>. <italic>obstrictus</italic> adults. Treatment with <italic>C</italic>. <italic>cyminum</italic> essential oil at 1.5% resulted in 50.71% mortality and 87.3% combined mortality and immobility in <italic>C</italic>. <italic>obstrictus</italic>. <italic>Cinnamomum verum</italic> oil, at 1.5% concentration, resulted in 88.8% mortality and immobility among <italic>C</italic>. <italic>obstrictus</italic> 24 h post-treatment. All treatments studied with essential oil dry residues at 0.3% concentration caused high mortality and immobility in <italic>N. vitripennis</italic>. The greatest mortality and immobility were observed at 0.3% concentration in <italic>F</italic>. <italic>vulgare</italic> and <italic>C</italic>. <italic>verum</italic> treatments (54 and 53% loss respectively). At 0.1% concentration, <italic>F</italic>. <italic>vulgare</italic> and <italic>T</italic>. <italic>vulgaris</italic> significantly reduced parasitoids mobility and at 1.5% concentration all essential oils resulted in 100% mortality of <italic>N</italic>. <italic>vitripennis</italic> after 3 h. Our study revealed that <italic>C</italic>. <italic>cyminum</italic> and <italic>C</italic>. <italic>verum</italic> essential oils may have potential in the management of <italic>C</italic>. <italic>obstrictus</italic>. However, their impact on non-target organisms, including parasitoids, needs to be studied more thoroughly to determine the potential of essential oil main compounds in integrated pest management.</p>