The frisbee was one of the great inventions of the baby boom generation. My professional model doesn't get quite as much flying time as it once did, so each spring I use it to breed mosquitoes. Since Memorial Day it has rested, inverted beneath an azalea collecting rainwater. By Father's Day it was chuck full of healthy wrigglers, the larval stage of mosquitoes. Some of the wrigglers are the spawn of the Tiger - the Asian Tiger mosquito. These beautiful swimmers feed by filtering small particles from the water with a set of mouth brushes reminiscent of Groucho Mark's mustachio. They breathe through a snorkel-like tube on their rear end that pierces the water's surface. Tiger wrigglers shed their skin, or molt, between four larval stages before turning into a tumbler, the pupal stage of the mosquito. Within just a day or two the pupal skin splits open along the midline and the adult mosquito rises wraithlike from the shell.
Mosquito larvae - wriggers (left); and mosquito pupa - tumbler (right).
Asian Tiger feeding on my wife's leg.
After the wings have expanded and hardened the mosquito flies off to find a meal. During the first several days of adulthood both males and females feed on carbohydrate rich food such as plant nectar or aphid honeydew. These sweets remain the source of food for the entire life of the male Asian Tiger. The female feeds intermittently on natural sugars but between bouts of sugar snacking she has a blood lust. Female mosquitoes use animal blood as the source of protein to produce eggs. After taking a blood meal, eggs develop within the abdomen of the female. The pregnant Tiger lays her brood in a container such as a tire, birdbath, or Frisbee near the water line. When the vessel fills with rainwater, the eggs hatch and larval development begins.
We believe the Asian Tiger arrived in this country by accident in water-filled tires from Asia. Large populations were found in Texas in 1985 and by 1987 detections were made in Maryland. Since its introduction, it has spread throughout much of the eastern United States. Unlike many of our native mosquitoes that dine primarily at dawn, dusk, or night, the Asian Tiger is a daytime biter, adding new hours of itching, scratching, and swatting to our summer days in the garden. This Tiger may be more than a nuisance as some fear that the Asian Tiger may carry important diseases such as West Nile Virus.
Protect yourself from these aggressive day-feeding Tigers by wearing light, long-sleeved shirts and pants when working outdoors. Apply insect repellents to exposed skin before you go outdoors. Be sure to read and follow the directions on the label of the repellent before you apply it to people or clothing. To reduce the chances of mosquitoes breeding around your home eliminate standing water by cleaning your gutters, dumping your bird bath twice a week, and getting rid of water filled containers such as cans, flower pots, and, well, frisbees.
References
To learn more about the Asian Tiger Mosquito visit the following web sites:
http://www.agnr.umd.edu/users/charlesmg/mosquito%5Cinsect_menace1.html