Mosquitoes bite more often due to night lighting

Sci­en­tists from the Uni­ver­si­ty of Notre Dame report that night­time light­ing increas­es the fre­quen­cy of mos­qui­to bites that pre­fer day­time activ­i­ty.

Dur­ing the exper­i­ment, one of the sci­en­tists allowed mos­qui­toes of the Aedes aegyp­ti species in cages to bite his hands at dif­fer­ent times of the day: dur­ing the day, at night, and at night, but under night illu­mi­na­tion with arti­fi­cial light sources. Mos­qui­toes of this species usu­al­ly feed dur­ing the day. How­ev­er, it turned out that in the lat­ter case, the females were twice as like­ly to bite and drink blood at night. Thus, only 29% of mos­qui­toes from the con­trol group (with­out light) and 59% of mos­qui­toes from the exper­i­men­tal group (with night light) fed at night.

Sci­en­tists con­clude that light pol­lu­tion can affect the spread of a num­ber of mos­qui­to-borne infec­tions — dengue, chikun­gun­ya, Zika, and oth­ers. Con­sid­er­ing that night light­ing is now the norm for most set­tle­ments, experts rec­om­mend using bed nets even where where night-feed­ing mos­qui­toes (genus Anophe­les, for exam­ple) are rare.

An inter­est­ing point: not every rep­re­sen­ta­tive of the Aedes aegyp­ti species ate at night, even under arti­fi­cial light. Sci­en­tists sug­gest that the ten­den­cy to night feed­ing is deter­mined by the genes of the insect.