ABSTRACT
Use of Plants throughout the Globe ............................................................................................... 180 Mosquito Coils .......................................................................................................................... 180 Natural Fumigants..................................................................................................................... 180 Effect of Natural Fumigants on Vector-Borne Disease Incidence ............................................ 182
Repellent Chemicals Identied in Plants ....................................................................................... 183 Why Are Plants So Repellent to Blood-Feeding Insects? ......................................................... 183 Alkaloids ................................................................................................................................... 184 Phenols ...................................................................................................................................... 184 Terpenoids ................................................................................................................................. 185
Essential Oils ........................................................................................................................ 185 Pyrethrins ............................................................................................................................. 185 Repellent Terpenes ............................................................................................................... 186
Volatility of Terpenes and Formulation to Improve Their Longevity ...................................... 191 Spatial Application ............................................................................................................... 191 Formulation to Improve Plant-Repellent Persistence ........................................................... 191
Commercial Repellents Developed from Plants ....................................................................... 192 Citronella Group Family: Poaceae ............................................................................................ 194
Ocimum spp. (Lamiaceae) .................................................................................................... 195 Hyptis spp. ............................................................................................................................ 195 Thymus ................................................................................................................................. 196
Lantana camara (Verbenaceae) ................................................................................................ 196 Daniellia oliveri (Fabaceae) ...................................................................................................... 198 Tagetes spp. (Asteraceae) .......................................................................................................... 198 Lippia spp. (Verbenaceae) ......................................................................................................... 198 Artemisia spp. ........................................................................................................................... 199 Neem ......................................................................................................................................... 199 Garlic .........................................................................................................................................200 Lemon-Eucalyptus Extract ....................................................................................................... 201
References ...................................................................................................................................... 201
USE OF PLANTS THROUGHOUT THE GLOBE
Plants were rst recorded being used against biting insects by the ancient Greeks,1 and are still used by enormous numbers of people today. Most households in the developing world rely on personal protection measures of limited effectiveness, such as burning leaves,2 despite the wide range of modern, effective malaria-control measures available, because they prefer to use an intervention that is free and widely available, despite its lower efcacy and undesirable characteristics such as strong odor.3