Insect biodiversity
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Insect Biodiversity
Why it’s important? Agriculture In agroecosystems, biodiversity is instrumentally important not only for the production of food, but for other ecological services as well, including the recycling of nutrients, regulation of microclimate and local hydrological processes, suppression of undesirable organisms and detoxification of noxious chemicals. In the United States alone, pollination by bees accounts for over $9 billion dollars of economic revenue (Robinson, et al. 1989). Some estimates allow that over 1/3 of the human diet can be traced directly or indirectly to bee pollination (McGregor, 1976). Losses of key pollinators have been reported in at least one region, or country, on every continent, except Antarctica, which has no pollinators. The Millennium Ecosystem Assessment concluded that with the global decline in the amount of pollinators, there is not a complete loss of fruit or seeds, but a significant decrease in quantity and viability in fruits, and a lower number of seeds. Food Sources Over 1000 species of insects are, or have been used as food somewhere in the world. Entomophagy, is common in central and southern Africa, Asia, Australia, and Latin America. Termites, crickets, grasshoppers, locusts, beetles, ants, bee brood, and moth larvae are examples of insects that are used as food sources. Insects are high in protein, energy, and a myriad of minerals and vitamins and can form up to 5-10% of the annual animal protein consumption by certain indigenous groups (Cranston and Gullen). Many insects are said to have a nutty flavor, along with a high nutritional content. Human Culture Early human civilizations held insects as an important element within their cultures. Most famously, the scarab beetles were central religious artifacts within Egyptian culture. Insect symbolism, such as the dung beetle portrayed as a potter, is seen in the East as well. The Chinese viewed cicadas as a symbol of birth or immortality, the San of the Kalahari believe the praying mantis represents creation and patience, and the Greeks as well created beautiful representations of scarab beetles using colorful stones.
The Scope Over 1 million species of insects have been described by taxonomists in the past 250 years, but current estimates of total insect diversity vary between 5-80 million species of insect. Beetles make up 40% of described insect species, but some entomologists suggest that flies and wasps, bees, ants could be as diverse or more so. Five orders of insects stand out in their levels of species richness, the wasps, bees and ants (Hymenoptera), flies (Diptera), beetles (Coleoptera), moths and butterflies (Lepidoptera), and the true bugs (Hemiptera).
Insect Conservation There are two approaches to the conservation of insects. Either humans set aside large portions of land using “wilderness preservation” as the motive, or confronting the particular processes that affect the charismatic vertebrates in order to achieve indirect conservation of insects. With biodiversity loss being a global problem, conserving habitat simply for species of insects is of low priority in the current environmental culture. Single-species conservation is said to preserve many other species indirectly, this preservation by default is referred to as the umbrella effect. “Charismatic species,” such as butterflies or large, colorful beetles, called flagship species, can expand public awareness and financial contributions for conservation efforts. Migratory species, such as the well-known monarch butterfly (Danaus plexippus), are in need of special conservation methods. One species may require several habitat locations for different periods in their migratory patterns. Insect conservation has been labeled in the past as a concern only for the affluent. The developing country of Papua New Guinea has a “happily ever after” ending in their attempts to preserve the world’s largest butterfly, the Queen Alexandra’s Birdwing (Ornithoptera alexandrae). This species is restricted to a very small range of habitat due to specificity in their diet. In the international market of insect collecting, the butterfly can retrieve up to US$2000. In 1978, the PNG government set up the Insect Farming and Trading Agency (IFTA) to regulate the exploitation and conservation of the Queen Alexandra’s birdwing and other valuable butterflies.
BIBLIOGRAPHY: Altieri, Miguel A. The ecological role of biodiversity in agroecosystems. Agriculture, Ecosystems and Environment 74 (1999) 19–31.
Cranston, P.S. and P.J. Gullan. The Insects: An Outline of Entomology. Oxford: Blackwell Publishing Ltd., 2005.
Millennium Ecosystem Assessment, 2005. Ecosystems and Human Well-being: Biodiversity Synthesis.World Resources Institute, Washington, DC.
McGregor SE. Insect pollination of cultivated crop plants. USDA Agriculture Handbook 496. Washington, D.C. 411. 1976.
Robinson, W. S., R. Nowogrodski & R. A. Morse. Pollination parameters. Glean. Bee Cult. 117: 148-152. 1989.
