Volatiles from Marina neglecta: Biocide effect on insect vectors of tropical diseases in Southern Mexico 

 -  Journal of Asia-Pacific Entomology, 24(2), p.243-249, 2021 .
<br/><br/> Preventive measures based in the control of insect vectors are considered as the best choice to decrease the incidence of insect-borne diseases. Herein we report on the volatile content of the leaf essential oils from Marina neglecta, a medicinal plant distributed in the tropical regions of southern Mexico. In order to investigate the chemical variation of the essential oils, a volatile screening was performed during the four seasons of the years 2016-2019. Simultaneously, their biological activity was tested on distinct life stages of Meccus pallidipennis, M. bassolsae, Aedes aegypti and A. albopictus. Essential oils were mainly constituted of ?-pinene (>30 percent)?-caryophyllene (>25 percent)and germacrene D (>13 percent). Dorsal-abdomen application of essential oils on triatomines, revealed an efficient IC50 for nymphs of the stages I to III (4 µg/insect), nymphs of the stages IV to V (5-6 µg/insect), and adults (7-8 µg/insect). The LT50 for the stages I to III was between 6 and 8 h, whereas that for the stages IV to V and adults oscillated between 12 to 16 h and 22 to 26 h, respectively. Fumigation experiments performed on nymph V, demonstrated that 300 µg L-1 air produced 100 percent mortality after 72 h post-treatment. Among tested volatiles, ?-pinene and ?-caryophyllene produced a comparable mortality rate (p < 0.01)than that of essential oils in the stages assayed. Essential oils showed strong larvicidal (LC50, 24-36 µg mL-1)and adulticidal (35-48 µg mL-1)activities in mosquito species with an LT50 of 4.5 h and 25-35 min, respectively. The evaluation of ?-pinene produced a significant mortality rate (p < 0.01)in larvae whereas germacrene D was the most effective volatile (p < 0.01)against adults of both mosquito species. According to our results, ?-pinene was the most effective volatile against the four insect species evaluated and its effect was comparable to that of the essential oil. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>MARINA NEGLECTA<br/>ESSENTIAL OIL<br/>BIOCIDE<br/>MECCUS PALLIDIPENNIS<br/>M. BASSOLSAE<br/>AEDES AEGYPTI<br/>A. ALBOPICTUS