Pellets appear to have
resolved Maui’s midge mess
KIHEI, Maui >> Synthetic hormonal pellets appear to have reduced the number of pesky "midge" flies at Kealia Pond National Wildlife Refuge, wildlife officials and neighbors said.
Refuge manager Glynnis Nakai said the number of midges this year were less than half the number that swarmed the pond in 2001, prompting numerous complaints from neighbors and visitors.
Rodger Mellema, residential manager at Kealia Condominium, said the application of the pellets in the pond must have reduced the number of flies.
Mellema said the midges usually hatch after a heavy rain but that this year there haven't been as many as in 2001.
Residents in north Kihei complained about large columns flying into neighborhoods and resorts three years ago to the point of forcing people to stay indoors.
Through federal funding, officials at the wildlife refuge in mid-February applied s-methoprene pellets to about half of the 200-acre pond.
The s-methoprene prevents midges from developing into their adult stage, where they are capable of flight.
Nakai said wildlife officials saw midges in 2002 and 2003, but their presence was considerably less than in 2001.
She said a decision was made to apply the pellets this year after residents called wildlife officials to report swarming columns of midges.
A scientific report about the effectiveness of the pellets is expected to be ready sometime between August and October, Nakai said.
She said the number of flying midges were counted at collection sites in the pond and there appeared to be fewer compared with previous years.
Midges, also known as Polypedilum nubifer and found in Australia and some Pacific islands, have black bodies about half an inch long and wingspans about a quarter of an inch wide.
Scientists say midges were reported as nuisances in South Maui as early as 1996, and sightings of them were reported on Oahu as early as 1945.
During the rainy season from January through March, millions of them have sometimes emerged from muddy waters of the refuge and joined into swarms in the mornings and at sunset.
Scientists say female midges enter large swarming columns of male midges to mate in flight, then fly away to lay their eggs.
The eggs become larvae, or bloodworms, that eventually form shells. After a period of growth, the shells rise to the surface of the water and split, allowing adult midges to take flight.
Earlier this year, a scientist who conducted a study at the pond said there may have been fewer midges earlier this year also because an increase in water levels resulted in fewer larvae.
The water dilutes the amount of food in the pond, said Martin Berg, a professor at Loyola University-Chicago.