Jason Farned set down a clear container in the middle of a table. The people gathered around leaned forward to peer at the tiny, zooming blurs trapped inside.
“The deadliest creature in the world is the mosquito,” said Farned, who works for the San Gabriel Valley Mosquito and Vector Control District, a government agency that manages insect populations. By some estimates, mosquitoes transmit diseases that kill more people each year than any other creature.
The ones Farned brought to this recent meeting in El Monte were Aedes mosquitoes — the kind that spread Zika virus, the disease discovered last year to cause birth defects.
Though no one has...