Removing the flowers of an invasive wild shrub from mosquito-prone areas may decrease the vector population by nearly 60 per cent, helping in reducing malaria cases, a recent study said.
The mosquitoes obtain most of their energy needs from plant sugars of the nectar Prosopis juliflora flowers (scientific name, also called Vilayati Babul or Junglee Kikar in India), the researchers explained.
In the study, the researchers tested the effect of the shrub — a robust plant native to Mexico that grows rapidly and has become one of the worst invasive plants in many parts of the world.
“Our results show that removal of this particular shrub reduces total population levels of mosquitoes and reduces the number of older female mosquitoes in the population, which are known to transmit malaria parasites to humans,” said lead author Gunter Muller from the Hebrew University Hadassah.
“This suggests that removal of the flowers could be a new way to shift inherently high malaria transmission areas to low transmission areas, making elimination more feasible,” Muller added.
The findings, published in the Malaria Journal, showed that villages in Mali where flowers of Prosopis juliflora were removed, mosquito numbers collected in the traps fell from an average of 11 to 4.5 for females, and 6 to 0.7 for male mosquitoes.
The total number of mosquitoes across these villages decreased by nearly 60 per cent after removal of the flowers.
After flower removal, the number of older more dangerous vector females in the population dropped to levels similar to those recorded in the villages that had no presence of the shrub, the researchers said.
“The presence or absence of Prosopis juliflora in villages has a significant influence on the size of the mosquito population in general, on their species composition, on the sugar feeding status and the age structure of female populations,” said John Beier from the University of Miami.