Fireflies belong to a widespread and economically important insect group, with more than 2,000 different species spread out across the globe, said the study, published in the journal Bioscience.
To better understand what threats are faced by fireflies, the research team surveyed firefly experts around the world to size up the most prominent threats to survival for their local species.
"Lots of wildlife species are declining because their habitat is shrinking, so it wasn't a huge surprise that habitat loss was considered the biggest threat. Some fireflies get hit especially hard when their habitat disappears because they need special conditions to complete their life cycle," said the study's lead author Sara Lewis, Professor at Tufts University in the US.
According to survey respondents, habitat loss is the most most critical threat to firefly survival in most geographic regions, followed by light pollution and pesticide use.
One surprising result that emerged from the survey was that, globally, light pollution was regarded as the second most serious threat to fireflies.
Artificial light at night has grown exponentially during the last century.
"In addition to disrupting natural biorhythms - including our own - light pollution really messes up firefly mating rituals," said the study's co-author Avalon Owens.
Many fireflies rely on bioluminescence to find and attract their mates, and previous work has shown that too much artificial light can interfere with these courtship exchanges.
Firefly experts viewed the widespread agricultural use of pesticides as another key threat to firefly survival.
Most insecticide exposure occurs during larval stages, because juvenile fireflies spend up to two years living below ground or under water.
Insecticides such as organophosphates and neonicotinoids are designed to kill pests, yet they also have off-target effects on beneficial insects.
While more research is needed, the evidence shows that many commonly used insecticides are harmful to fireflies.
A few studies have quantified firefly population declines, such as those seen in the tourist-attracting synchronous fireflies of Malaysia, and the glowworm Lampyris noctiluca in England.
And numerous anecdotal reports suggest that many other firefly species across a wide range of habitats have also suffered recent declines.
By illuminating threats and evaluating the conservation status of firefly species around the world, researchers aim to preserve the magical lights of fireflies for future generations to enjoy.
( With inputs from IANS )