New trap to kill Zika, Dengue and Chikungunya mosquitoes

Argentinian researchers came up with a new ovitrap (a trap for mosquitoes) that can be used to monitor and control the Aedes aegypti mosquito, which is the primary transmitter of Zika, dengue, chikungunya and yellow fever. 

The plastic ovitrap, as described in the Journal of Medical Entomology, is a handle-less small cup made out of low-density polyethylene (LDPE), infused with a larvicide called pyriproxyfen. 

Larvicide is an insecticide that is specifically targeted against the larval life stage of an insect, in this case, mosquitoes. On the other hand, ‘pyriproxyfen’ is a juvenile hormone analogue and an insect growth regulator. In simpler terms, it prevents larvae from developing into adulthood and makes them unable to reproduce. 

Pyriproxyfen likes to move around in the environment. If it’s moulded into a plastic cup, it immediately gets released from the plastic once the cup gets filled with water.

Female Aedes aegypti mosquitoes prefer to deposit eggs in small containers such as pots and tires that contain water. That’s what makes this plastic ovitrap an attractive egg-laying location for them. 

Grayson Brown, an entomologist at the University of Kentucky believes that this is a great idea. “When I read through the paper, I immediately started thinking of disposable liners for drain pans and outside potted plants, and disposable liners for birdbaths,” he said to entomology today. 

There was an old dispute about pyriproxyfen that states that it causes microcephaly, a condition where the head of newborn babies becomes smaller than normal. But this claim is already debunked by Entomological Society of America. 

The Brazilian government also stated that the association between use of pyriproxyfen and microcephaly doesn’t have any scientific basis. 

While this new ovitrap got high appreciation from the scientist world. Grayson Brown did found out some minor issues with the system. The pyriproxyfen-containing cups are subject to the vagaries of weather and human activity. Rain can easily wash the cup away and people can knock them over. 

Besides that, pyriproxyfen can be partially inactivated by sunlight. The cups will work best when placed in the shade, which may be advantageous for the Aedes aegypti as they prefer to be in the shade, according to Dr Brown. 

Laura Harburgues, lead researcher of the team that came up with this ovitrap acknowledged this issue of people upsetting the ovitrap. She plans to prevent that by acknowledging people in the community where the traps are used. 

While the trap has some minor issues, Brown believes that this is a very potential tool to control mosquitoes. 

The new ovitrap is expected to be up for field trials this fall, in between September to December.