Mosquito Control With Birds and Other Natural Predators

Mosquito Control With Birds and Other Natural Predators When the topic of  mosquito control is discussed, thrown into the mix is usually a fervent argument for installing purple martin houses and bat houses. Stores that cater to bird enthusiasts often tout the purple martin houses as the best solution for keeping your yard mosquito free. Bats, which may not be the most beloved of mammals, are defended with the claim that they consume hundreds of mosquitoes per hour. The truth of the matter is that neither purple martins nor bats provide any significant measure of mosquito control. While both eat mosquitoes, the insect makes up a very tiny portion of their diets. Other animals might have an upper hand on mosquito control, particularly in the fish, other insect, and amphibian classes. Mosquito Munchies For bats and birds, mosquitoes are more like a passing snack. Multiple studies of wild bats have consistently shown that mosquitoes consist of less than 1 percent of their diet. In purple martins, the percentage of mosquitoes in their diet is slightly higher- about 3 percent, at most. The reason is simple. The payoff is small. A bird or a bat that feeds on insects must invest considerable energy in flying around and must catch the bugs in mid-air. Birds and bats are usually seeking the biggest caloric bang for their buck. Given the choice between a mosquito morsel, a hardy beetle, or a mouthful of moth, the mosquito hardly makes the top-10 list. An Efficient Mosquito Natural Predator Gambusia affinis, also known as the mosquitofish, is an American fish that is utilized by some mosquito control districts across the country as a very effective predator of mosquito larvae. As far as natural predators go, the mosquitofish is by far the most efficient natural predator of mosquitoes. The mosquitofish is a voracious predator. In certain studies, mosquitofish have been shown to consume up to 167 percent of their body weight in invertebrate prey, including mosquito larvae, per day. Mosquitofish, as well as small predatory fish such as guppies, can be quite useful in the reduction of mosquito larvae given the right conditions. Other Mosquito Consumers The closely related  dragonflies and damselflies  are natural predators of mosquitoes but do not consume enough mosquitoes to cause a significant impact on the wild mosquito population. Dragonflies are often referred to as mosquito hawks for an unsubstantiated claim of being able to kill thousands of mosquitoes. One thing that does make the dragonfly a better predator than most is that, in the aquatic larval stage, one of their food sources is mosquito larvae. Dragonfly larvae can sometimes live up to six years in this stage. During this phase of life, dragonflies do the most damage to mosquito populations. Frogs, toads, and their young tadpoles are often touted as excellent for mosquito control. In reality, while they do consume their fair share, it is not enough to seriously put a dent in vast mosquito populations. When frogs and toads do consume mosquitoes, it is usually after they have transformed from tadpole to adult.

Tropical Rainforests Are Natures Medicine Cabinet

Tropical Rainforests Are Nature's Medicine Cabinet Tropical rainforests, which account for only seven percent of the world’s total land mass, harbor as much as half of all known varieties of plants. Experts say that just a four-square-mile area of rainforest may contain as many as 1,500 different types of flowering plants and 750 species of trees, all which have evolved specialized survival mechanisms over the millennia that mankind is just starting to learn how to appropriate for its own purposes. Rainforests Are a Rich Source of Medicines Scattered pockets of native peoples around the world have known about the healing properties of rainforest plants for centuries and perhaps longer. But only since World War II has the modern world begun to take notice, and scores of drug companies today work in tandem with conservationists, native groups, and various governments to find and catalog rainforest plants for their medicinal value, and synthesize their bio-active compounds. Rainforest Plants Produce Life-Saving Medicines Some 120 prescription drugs sold worldwide today are derived directly from rainforest plants. According to the U.S. National Cancer Institute, more than twos abound. Ingredients obtained and synthesized from a now-extinct periwinkle plant found only in Madagascar (until deforestation wiped it out) have increased the chances of survival for children with leukemia from 20 percent to 80 percent. Some of the compounds in rainforest plants are also used to treat malaria, heart disease, bronchitis, hypertension, rheumatism, diabetes, muscle tension, arthritis, glaucoma, dysentery, and tuberculosis, among other health problems. Many commercially available anesthetics, enzymes, hormones, laxatives, cough mixtures, antibiotics, and antiseptics are also derived from rainforest plants and herbs. Stumbling Blocks Despite these success stories, less than one percent of the plants in the world’s tropical rainforests have even been tested for their medicinal properties. Environmentalists and health care advocates alike are keen to protect the world’s remaining rainforests as storehouses for the medicines of the future. Fueled by this urgency, pharmaceutical companies have entered agreements with tropical countries promising protection against exclusive bioprospection rights. Unfortunately, these agreements didnt last, and enthusiasm waned.  In some countries, bureaucracy, permits, and access became prohibitively expensive. In addition, new technologies allowed to use powerful combinatorial chemistry techniques to find active molecules without having to slog through the mud in some faraway jungle. As a result, the exploratory search for pharmaceuticals in rainforests dwindled for a while. But the technological advancements which favored synthetic, lab-developed meds are now helping botanical prospectors once again, and a few daring pharmaceutical companies are back in the jungles looking for the next big drug.   The Challenge of Preserving Valuable Rainforests But saving tropical rainforests is no easy task, as poverty-stricken native people try to eke out a living off the lands and many governments throughout the world’s equatorial regions, out of economic desperation as well as greed, allow destructive cattle ranching, farming, and logging. As rainforest turns to farm, ranch and clear-cut, some 137 rainforest-dwelling species- plants and animals alike- go extinct every single day, according to noted Harvard biologist Edward O. Wilson. Conservationists worry that as rainforest species disappear, so will many possible cures for life-threatening diseases. How You Can Help Save Rainforests You can do your part to help save rainforests around the world by following and supporting the work of such organizations as Rainforest Alliance, Rainforest Action Network, Conservation International and The Nature Conservancy. EarthTalk is a regular feature of E/The Environmental Magazine. Selected EarthTalk columns are reprinted on About Environmental Issues by permission of the editors of E. Edited by Frederic Beaudry.