Messing with midges

Why kill larvae of a non-biting, non-disease-carrying insect that are essential to ecosystem?

It isn't every day that a Republican governor gets cast in the role of spendthrift by a penurious Democratic county executive, but that's essentially what has happened in the matter of some annoying flying insects in eastern Baltimore County. Small flies known as "midges" have been a nuisance for marinas in the Back River area in recent years, and state Sen. Johnny Ray Salling has been pushing for a government-financed pesticide application.

After a bill to authorize tax dollars on midge eradication failed in the General Assembly last spring, Gov. Larry Hogan came up with an offer to help out the Republican lawmaker — the state would kick in half the funds for a $1.3 million, one-year insecticide spraying this fall if Baltimore County Executive Kevin Kamenetz came up with the other half. Last week, Mr. Kamenetz's environmental protection director sent his response: Thanks, but no thanks.

The problem? By Vincent J. Gardina's calculation, the money spent on Bti, or Bacillus thuringiensis israelensis, a chemical derived from a naturally occurring bacteria that can kill midge larvae but is harmless to other animals, would hardly put a dent in the midge population. The larvicide might eradicate midges in 1 percent to 2 percent of the affected area, he wrote, but there's simply no scientific evidence it would be effective in reducing the midge population in the Back River.

Naturally, the rejection carried political overtones, as Mr. Kamenetz is widely rumored to be a potential candidate for statewide office in 2018. And it wasn't the first time that the two politicians found themselves at loggerheads over spending Mr. Hogan felt was essential and Mr. Kamenetz found wasteful. The governor's push for costly portable air conditioning units in Baltimore and Baltimore County schools has been similarly resisted by the county executive, who so far has chosen to spend tax dollars on speeding up central air installations instead.

The similarities continue. What would really solve the midge problem, as Mr. Gardina also pointed out, is to further upgrade the nearby city-owned Back River Wastewater Treatment Plant, not apply the bandage of pesticide. It's the nitrogen and other nutrients pouring out of the plant that are feeding river phytoplankton which, in turn, provide sustenance for the midges. Improvements to the plant are already underway (including a $9.1 million loan approved by the Board of Public Works just two weeks ago), but it's not clear whether they will be sufficient given how some of the nutrients in the river have accumulated over decades.

So why such a fuss? One can only assume Governor Hogan wants to help Senator Salling look like a hero to his constituents. Thick clouds of midges aren't a public health threat, as they don't carry disease or bite, but try hanging out near the water when a swarm descends. It isn't fun. And marinas can't afford to spray Bti on hundreds of acres of water on their own. By state budget standards, the amount involved is midge-sized, and it sends Mr. Hogan's essential political message: We're here to help local businesses.

Yet like the air conditioning issue, where the county has been pressured by the governor to spend millions on rewiring classrooms for AC units that might be needed only a handful of days, Mr. Kamenetz appears to be in the right. Bti isn't likely to be effective because of the scale involved. (VectoBac, a pesticide containing Bti commonly used for mosquito control in Maryland, is not recommended for large bodies of water like Back River because of the dilution effect.) And while the product is remarkably safe (the EPA even allows it on organic farms), killing midge larvae means messing with the food chain, as the tiny larvae are food for larger insects which, in turn, feed fish, then larger fish and birds and mammals.

Even a 2014 state study that recommends Bti application suggests that it only be attempted near the areas where people are complaining and would then require "multiple treatments per year, every year" and that given the large number of eggs one midge can produce, "any cessation in treatment will result in a rapid increase in the number of midges." That makes spraying a lot more costly than $1.3 million if it means a decade or more of applications. Better to invest more money in fixing the real problem — pollution from the Back River sewage plant — than further mess with Mother Nature, the local ecosystem and the health of the Chesapeake Bay. Let marina and boat owners buy some UV insect "zap" traps rather than zap taxpayers on this one.

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