Is it a bird? Is it a plane?

Tuesday through Thursday, it will be a low-flying helicopter dropping larvicide on marshy, non-residential areas of Queens, Staten Island, Brooklyn and the Bronx between 6 a.m. and 7 p.m.

It’s the fifth time this year that the city will spray the larvicide to destroy mosquito eggs in the effort to defeat the Zika and West Nile viruses.

The Health Department “will use naturally occurring and environmentally friendly larvicides,” such as VectoMax, it said in a statement.

In the event of bad weather, the spraying will be delayed until Friday through Sunday.

The most effective way to curb mosquito proliferation is to eliminate standing water, as mosquitos can breed in any water that has been standing for more than four days.

New Yorkers are encouraged to mosquito-proof their homes by removing all standing water, making sure roof gutters are clean and draining properly, keeping all pools chlorinated and covered when not in use, and making sure screens are tight and in good repair.

Residents should also use an approved repellent containing picaridin, DEET, oil of lemon eucalyptur (not for children under age 3), or products that contain the active ingredient IR3535.

The spraying schedule can be found online at http://www1.nyc.gov/site/doh/health/health-topics/west-nile-virus-spray.page or check the @nychealthy account on Twitter.