Here is a current Consumer Reports publication on the the subject:

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Quote
We advise skipping most products made with natural plant oils, such as California Baby Natural Bug Blend (a blend of citronella, lemongrass oil, cedar oil, and other ingredients) and EcoSmart Organic, (which includes geraniol, rosemary oil, cinnamon oil, and lemongrass oil). They did not last for more than 1 hour against Aedes mosquitoes, and some failed almost immediately.