As far as natural repellents are concerned, plant-derived insect repellents yield short-lasting protection, lasting from a few minutes to as long as 2 hours.
Examples are citronella, soybean and eucalyptus oils; of the 3, eucalyptus (pmd) works best. In a 6-hour field study, 20% pmd prevented bites as well as a 20% deet. Marketed products include repel oil of eucalyptus repellent, off! botanical, .