Fungus gnat joins small genus


A new species of fungus gnat discovered near Limantour Road in the Point Reyes National Seashore might be part of the genus Megophthalmidia, which contained just a single species until a scientist for the California Department of Food and Agriculture announced the discovery of it and seven others this month. The brown, fuzzy body of the gnat Peter Kerr found in the seashore, M. saskia, is just three millimeters long, about the same length as its limbs. Scientists have had difficulty identifying fungus gnats because their bodies are delicate: if they are not properly dried out, they will turn into mush, Dr. Kerr said. They lay their eggs on mushrooms or other fungi, and once the larvae emerge they munch away—and exhibit tastes similar to humans. “We are rivals, fungus gnats and us, because we tend to like the same mushrooms,” he said. Sometimes fungus gnats can help mushrooms propagate by spreading their spores, but, he added, they also eat them. To find and study gnats, Dr. Kerr sets up tent-like traps in areas where a variety of mushrooms grow. Insects will bump into a vertical panel of netting and instinctively fly upward, where they will meet another net. The traps are constructed so that the gnats are lured into a plastic jar attached to another vessel holding alcohol. “They’ll smell the alcohol, they’ll get tired and eventually fall into the alcohol,” said Dr. Kerr. Much remains unknown about the new gnat: Dr. Kerr isn’t sure exactly which mushrooms they eat, or what their lifespan might be. In fact, he’s not even sure that M. saskia truly belongs in the genus he placed it in; it might instead belong in an entirely new genus. Dr. Kerr plans on undertaking a family history to trace the lineages of various fungus gnats to determine its proper categorization.