Midge or mayfly? Avoidance more important to tourists

Each spring and summer, those living or visiting the Lake Erie shoreline deal with a large number of annoying bugs. All are eaten by fish, birds and other animals while available in their nymph, larval and/or adult life stages.When aquatic insects exit the lake, it is often erroneously called a hatch, when in fact, it is actually an emergence. The hatch occurs when a larva or naiad first exits its egg.Although residents usually learn to ignore the insects during the short periods of peak abundances, visitors to the lakeshore are often seen panicking while swatting at the harmless midges and mayflies that appear each season.If a friend or family member happens to be visiting while these insects are present in biblical proportions, it helps to be able to act as the resident expert to calm their fears by being able to identify and offer some information about them.Midges are families of insects that include biting and non-biting varieties. Travelers to the North Country have to deal with 'midgies' or tiny 'no-see-ums' that deliver painful bites and lingering welts.Fortunately, the larger midges most often encountered on Lake Erie are non-biting varieties, locally known as muffleheads. About the size and shape of a mosquito, they differ by having a pair of large, fluffy antennae and no proboscis to draw blood through.Their bright red larvae, commonly called 'bloodworms,' contain hemoglobin in their blood, which allows them to tolerate low-dissolved oxygen conditions that commonly occur in the soft mud that they inhabit. They contribute significantly to the diet of important fish species, notably yellow perch.Midges become extremely numerous in sediments, which do not support the insect larvae that require higher-dissolved oxygen levels. Unfortunately, that includes most of the lake's bottom.Their swarms can be so thick that they may look like a tire or an oil fire burning along the shoreline treetops some nights at dusk, especially in May. They may also be flushed in distracting numbers when walking through grass or past buildings on mornings following a big emergence.Midges sometimes emerge in the fall. Some may recall the 2007 Cleveland Indians playoff game when New York Yankees pitcher Joba Chamberlain was freaked out by the midges flying around his face on the mound.Mayflies can be recognized by their large, lacy wings, long cerci (tail spines) and slow, deliberate flight. The larger ones seen here each summer are burrowing species, with other smaller species living upon shallow rocks. They can only persist when there are adequate year-round dissolved oxygen levels at the water/mud interface.Locally, they are also called Canadian soldiers, fish flies or June bugs. Their populations started to recover in the mid-1990s and scientists celebrated their return as further evidence that the lake had truly recovered.Unfortunately, high dissolved phosphorous levels have reversed the lake's short-lived recovery once again, causing a decline in larval mayfly densities. Massive algae blooms lead to oxygen depletion as decomposer bacteria feed on dead cells at the bottom of the lake.Wherever mayflies thrive in good numbers, yellow perch and other fish regularly consume the larva from the mud. Walleyes, white bass and smallmouth concentrate on them as they emerge from the mud and rise to launch themselves from the water's surface.When the weak-flying insect emerges from the water as a sub-adult, they are often steered according to the prevailing wind direction to the shoreline or nearby islands. Their numbers in June and July can be staggering enough to even display on Doppler weather radar, resembling densities similar to a moderate rainfall.After spending a day above water, typically perched off the ground, they shed their skin one more time to reach the adult stage. In the meantime, birds and other animals fill up on this readily available source of protein. There are no skinny birds, fish, spiders or raccoons during mayfly season.At dusk, a well-recognized male courtship dance, consisting of a repetitive short flight up followed by fluttering down begins. If he gets lucky, he will grab a female that gets too close and mate — before she goes to the surface of the water to release the fertilized eggs and dies.The mayfly emergence has a tremendous effect on the lake, including anxiety for non-familiar tourists, tougher fishing conditions and large piles of odiferous carcasses to clean up each morning near where lights have shined overnight.Yet, their presence should be celebrated, not cursed.