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the Culicidae mosquito Aedes albopictus. At a dosage of 300 ppm lavender essential oil

showed 55% larval mortality rate [26].

11.3.4

Citronella oil

Essential oils and extracts belonging to plants in the citronella genus (Poaceae) are

commonly used as ingredients of plant - based mosquito repellents. Citronella is an es-

sential oil extracted from the stems and leaves of different species of lemongrass (Cym-

bopogon spp.). It is used on humans and their clothing – in the form of oil, liquid and

patch. The active compounds in citronella oil for repelling mosquitos are camphor, euca-

lyptol, eugenol, linalool, citronellal and citral [29]. Citronella oil is a natural, non-toxic

alternative to chemical insect repellents such as DEET, therefore, is usually the preferred

choice. Disadvantage is that citronella oil rapidly evaporate and the effectiveness to deter

mosquito biting lasts very short [30]. A field study from Bolivia has shown that a 100% of

citronella oil (C. citratus) applied topically provide 74% protection against An. darlingi for

2.5h and 95% protection against Mansonia for 2.5h [29]. One research team have tested

the repellency protection of the citronella essential oil (C. winterianus) against the three

mosquito species, Ae. aegipty, C. quinquefasciatus and A. dirus and the results show100%

efficiency for 3h, 8h and 3.5h, respectively [31]. Trongtokit and his coworkers have shown

that the topical application of 100% citronella oil (C. nardus) can provide complete pro-

tection against same three mosquito species for a particular time in a laboratory setting

[30].

11.3.5

Basil oil

Basil is an annual plant of the Ocimum genus, which belongs to the Lamiaceae family

and is used in traditional medicine in many parts of the world. In the laboratory trial, 20%

basil oil solution, with mean percentage repellency of 66.7%, had 100% protective impact

against An. stephensi for 3.5h [32]. Phasomkusolsil and colleagues used basil essential oil

at 0.02, 0.10, and 0.21mg/cm² concentrations against An. dirus. The percentage repel-

lency was dose–response and was reported to be 66%, 74% and 96%, respectively [33].

Adam and the associates have analyzed the repellent efficiency of topically applied es-

sential oil extracted from O. basilicum, against malaria vector Anopheles mosquito. Three

different concentrations of basil oil were tested, 2, 4 and 6% of the oil. The obtained results

show relatively high repellency effect of 6% concentration of the oil, more than 250 min

[34]. One work has found that basil oil of O. americanum provides 100% efficiency for 3

h, 3.5 h and 8 h against Ae. aegipty, A. dirus and C. quinquefasciatus, respectively [31].

11.3.6

Thyme oil

Thymus species have been reported to possess various beneficial effects, such as an-

tiseptic, carminative, antimicrobial, and antioxidant properties. The 20% oil solution of

thyme in the study conducted by Amer et al. with 100% protection against An. stephensi

for 7.5 h, had a good effectiveness in preventing Anopheles mosquitos [31]. Thyme es-

sential oil of T. vulgaris had potent repellent activity against Culex pipiens pallens, with a