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Abstract, ICPE, 2021

The International Centre of Insect Physiology and Ecology (icipe) has generated new evidence of the immense threat posed by a highly destructive invasive plant, known scientifically as Parthenium hysterophorus, towards probable escalation of malaria incidents in East Africa.

In a study published on 20th July 2021 (https://rdcu.be/cpfvh), the Centre demonstrates that the weed, which has aptly earned the alias of ‘famine weed’ due to its phenomenal adverse impact on people’s health, agriculture, livestock and the environment, has contrastingly favourable effects on Anopheles mosquitoes, which transmit the malaria parasite. Also, the researchers note the possibility of exploiting the Parthenium-mosquito relationship to control the insects. 

“In general, mosquitoes lay their eggs in standing water. However, we have established that Parthenium releases from  its roots, chemicals known as terpenes that have a distinct blend of mosquito-attractive fragrances. When these chemicals leak into stagnant water, they enhance its attractiveness as an egg laying site for mosquitoes, in comparison to plain water,” explains Prof. Baldwyn Torto, Head, icipe Behavioural and Chemical Ecology Unit (BCEU). 

He adds: “As our research further demonstrates, this preference has major implications on the ability of mosquitoes to survive and thrive. The Parthenium root chemicals enable mosquito larvae to emerge two to three days earlier, and they also extend the lifespan of the adult mosquitoes arising from the contaminated breeding sites to a week longer than normal, thus boosting their chances to bite people and transmit the malaria parasite.”