By Steve Carbol, Lake & Wetland Management Senior Biologist
Florida, like a lot of places, has garnered some well-established, clichéd perceptions. Florida is such a unique locale within the United States that the list of stereotyped clichés, deeply ingrained and inseparable from our identity as Floridians, has become quite lengthy; copious sunshine, fresh citrus, alligators, swaying palms, Disneyworld, spring breakers, retired seniors, hurricanes, increasingly ridiculous headlines, and the creature some jokingly refer to as our state bird, the mosquito. And when it comes to Florida’s mosquitoes, admittedly, the hype is real. Sure, Florida has mosquitoes, about 80 native and exotic species in total. It’s a state dotted by lakes, crisscrossed by canals, and blessed with year-round, nonstop warm weather. Of course, Florida has mosquitoes, and midges too. In this installment, we’ll delve into the life of this irritating but amazing little fly and that of its lookalike cousin, the midge, and some practical, eco-friendly strategies to control them both.
Midges, Mosquitoes, What’s the Difference?
The word midge has become a generic catch-all wastebasket term applied to several disparate families of tiny flies, some of which have a fearsome bite, especially for their diminutive size. Within the scope of this article, we’ll specifically discuss the non-biting Chironomid midges. Both mosquitoes and midges are flies and superficially look very similar in appearance. A subtle but reliable field mark to differentiate the two is the way the legs are held when perched. Midges tend to raise their forelegs into the air when resting, while mosquitoes favor cocking their hind legs up.
Both midge and mosquito eggs require water to develop, which explains why Florida is such a haven for the little insects. Both insects spend most of their life cycles in water with aquatic eggs, larvae, and pupae, then undergo metamorphosis to emerge into the terrestrial world as winged, flying adults. That being said, the insects’ juvenile aquatic lifestyles are worlds apart. Upon being laid, midge eggs sink to the bottom and once hatched, the young live there as benthic, crawling, slender caterpillar-like larvae, breathing through tufts of gills on their posteriors. These deep red midge larvae are known as bloodworms and are popular in the aquarium trade as fish food. Midge larvae also pupate on the bottom or crawl up plant stems and pupate near the water’s surface. Mosquitoes, on the other hand, lay floating eggs, either singly or in large rafts depending on the species. After hatching, mosquito larvae and pupae spend their childhood free-swimming at the water’s surface breathing atmospheric air through a snorkel.
Both midges and mosquitoes feed on microscopic organisms and detritus as larvae, and on flower nectar, sap, and other sweet liquids as adults. “But wait”, you say, “Mosquitoes drink blood”. But wait, I say, I’m getting to that. Hold your horseflies. It might seem odd to think of vampiric, ectoparasitic mosquitoes daintily sipping nectar at flowers like gentle butterflies. Contrary to how it can feel when being eaten alive by a mosquito swarm deep in one of Florida’s remote wild areas, not all mosquito species consume blood, and among those that do, many don’t target humans and instead specialize in feeding on other animals such as birds or frogs. Further, in those mosquito species that bite and suck blood, it’s only the females that do so (insert joke here, fellas, but do so at your own risk). Typically, most mosquitoes, both male and female, like their non-biting Chironomid midge cousins, take a liquid vegetarian diet, feeding on flower nectar, plant juices, and other sweet liquids. Those female mosquitoes that do drink blood, do so only temporarily for a protein, nutrition, and calorie boost to supply the extra energy needed to produce eggs or increase egg production.
Why are Midges Difficult to Control?
Though Chironomid midges don’t bite, they can still draw the ire of lakeside residents by virtue of their sheer numbers. As mentioned earlier, Chironomid midge larvae are known as bloodworms and their deep red pigment is due to extremely high concentrations of hemoglobin in their bodies. Hemoglobin in blood carries oxygen to body tissue and lungs or, in the case of midge larvae, gills. Midge larvae are tenaciously tough and supremely adapted to live in the most stagnant, oxygen-starved water of the poorest quality that will support little other life. Most “lakes” in Florida communities are actually unnatural, human-dug storm-water retention basins that accumulate a thick benthic muck layer of decomposing plant matter and a toxic stockpile of sediment and pollutants that wash down into the basin from the land. These conditions are often just too extreme to support much aquatic life, including potential midge predators such as the larvae of dragonflies, damselflies, and predacious diving beetles. Meanwhile, the tough, well-adapted, little, hemoglobin-rich midge larvae are quite happy enjoying a quiet, predator-free lifestyle down in their anaerobic, toxic muck. The size of a midge population in one lake bottom can be truly staggering and when all these midges pupate and emerge as adults at once their numbers can be overwhelming. One emergence can persist for weeks as clouds of midges crowd shorelines and swarm electric lights at night, sometimes leaving thousands of dead midge corpses stuck to walls, under eaves, cluttered around light fixtures, drowned in swimming pools, and piled in drifts on porches and patios.
Midge & Mosquito Control Solutions
Lake & Wetland Management employs several environmentally-friendly techniques to combat midge and mosquito infestations. Implementing various tactics in concert targets the insects at different life stages and ensures increased success, culminating in the cultivation of healthy, balanced, beautiful waterways that benefit both lakeside human residents and local native wildlife. Lake & Wetland Management has found great success in midge and mosquito control with the following strategies:
In lieu of indiscriminate chemical pesticides that can potentially harm humans, pets, and wildlife, Lake & Wetland Management recommends VectoBac, a naturally-occurring, biodegradable bacteria product, registered for use by the EPA and recommended by the World Health Organization for control of midge and mosquito larvae. VectoBac utilizes Bacillus thuringiensis, the same bacteria used to combat devastating, massive, invasive Gypsy Moth caterpillar hordes in the northeast U.S. VectoBac targets aquatic insect larvae including Chronomid midges, mosquitoes, Yellow Flies, horseflies, and biting midges (“no-see-ums”) and can help combat insects that carry Zika Virus, canine heartworm, and various strains of encephalitis, diseases and parasites that threaten humans, dogs, birds and horses. Used on a regular maintenance schedule, VectoBac can significantly reduce the number of midge and mosquito larvae in a water body.
Enzyme & Bacteria Treatment
Since midge larvae thrive in the thick, toxic, anoxic muck on lake bottoms, breaking up and reducing that layer through the application of beneficial, natural enzymes and bacteria makes lake bottoms less hospitable for the insects. Enzyme and bacteria treatments improve the lake bottom’s overall environmental conditions, especially for the midge’s insect predators like dragonfly and damselfly larvae and predacious diving beetles, which reduce midge numbers even further. Installing a benthic plate-diffuser aeration system increases oxygen flow throughout the lake’s water column and helps to even more efficiently circulate and disperse enzymatic and bacterial treatments throughout the system.
The Eastern Mosquitofish is native to Florida and, as its name implies, is a mosquito specialist predator. Mosquitofish are tough, adaptable, little fish that devour mosquitoes at all life stages; eggs, larvae, and pupae as well as adults alighting on or emerging at the water’s surface. Any adult midges landing on or emerging at the water’s surface are also eaten with equal relish.
Once installed, mosquitofish naturally reproduce to offer environmentally-friendly year-round mosquito control, generation after generation.
Bat Box Installation
Bats are natural predators of midges and mosquitoes and fly at dusk and night when the adult insects are most active. One insectivorous bat can consume its weight in midges and mosquitoes in one night, and the number of insects consumed by a colony in the course of a year can be simply staggering. Installing bat boxes on poles or outbuildings near water is an effective and very inexpensive way to provide midge and mosquito control as well as provide a safe refuge for Florida’s amazing native bat species.
Many communities and individuals invest in waterfront property for the beautiful aesthetic and lifestyle it brings, only to have a lovely lakeside evening ruined by swarms of noisome midges and mosquitoes. Lake & Wetland Management, an industry leader, is a natural, eco-friendly midge and mosquito control specialist. For more information on midges and mosquitoes and the variety of green control techniques available, please contact your local Lake & Wetland office or visit us online at www.lakeandwetland.com.