Advances in mosquito repellents: effectiveness of citronellal derivatives in laboratory and field trials. Issue 12 (14th September 2022)

• Record Type: Journal Article
• Authors: Iovinella, Immacolata; Caputo, Beniamino; Cobre, Pietro; Manica, Mattia; Mandoli, Alessandro; Dani, Francesca Romana
• Is Part Of: Pest management science. Volume 78:Issue 12(2022)
• Page Start: 5106
• Page End: 5112
• Publication Date: 2022-09-14
• Subjects: malaria -- dengue -- chikungunya -- essential oils -- human bait -- hydroxylated acetals; Pests -- Control -- Periodicals; Pesticides -- Periodicals; 632.9
• DOI: 10.1002/ps.7127
• Languages: English
• ISSNs: 1526-498X

Abstract

Abstract: BACKGROUND: Several essential oils, including citronella (lemongrass, Cymbopogon sp., Poaceae), are well‐known mosquito repellents. A drawback of such products is their limited protection time resulting from the high volatility of their active components. In particular, citronella oil protects for <2 h, although formulations with fixatives can increase this time. RESULTS: We synthesized hydroxylated cyclic acetals of citronellal, the main component of citronella, to obtain derivatives with lower volatility and weaker odour. The crude mixture of isomers obtained in the reaction was tested under laboratory conditions for its repellency against two mosquito species, the major malaria vector Anopheles gambiae and the arbovirus vector Aedes albopictus, and found to be endowed with longer protection time with respect to DEET ( N, N ‐diethyl‐meta‐toluamide) at the same concentration. Formulated products were tested in a latin square human field trial, in an area at a high density of A. albopictus for 8 h from the application. We found that the performance of the citronellal derivatives mixture is comparable (95% protection for ≤3.5 h) with those of the most widespread synthetic repellents DEET and Icaridin, tested at a four‐fold higher doses. CONCLUSIONS: Modifying the hydrophilicity and volatility of natural repellents is a valuable strategy to design insect repellents with a long‐lasting effect. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Abstract : The mixture of hydroxylated cyclic acetals, obtained from condensation of citronellal with glycerol, was tested for its repellency against mosquitoes and showed a longer‐lasting protection in comparison to DEET.