Insect biodiversity

Insect biodiversity accounts for a large proportion of all biodiversity on the planet, with over 1,000,000 insect species described.

Agriculture

In agricultural ecosystems, 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 US$9 billion of economic revenue .^[1] According to some estimates, over ⅓ of the human diet can be traced directly or indirectly to bee pollination .^[2] 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 ^[3] 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

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 number of minerals and vitamins and can form up to 5-10% of the annual animal protein consumption of certain indigenous groups .^[4] Many insects are said to have a nutty flavour, along with a high nutritional content.

Human culture

Early human civilisations held insects as an important element within their cultures. Most famously, 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 that the praying mantis represents creation and patience, and the Greeks also created beautiful representations of scarab beetles using colourful stones.

Number of species

Over 1 million species of insects have been described, but current estimates of total insect diversity vary from 2.6-7.8 million species with a mean of 5.5 million.^[5] Beetles (Coleoptera) make up 40% of described insect species, but some entomologists suggest that flies (Diptera) and Hymenoptera (wasps, bees and ants) could be as diverse or more so. Five orders of insects stand out in their levels of species richness: Hymenoptera, Diptera, Coleoptera, Lepidoptera, and the Hemiptera. A recent study estimated the number of beetles at 0.9-2.1 million with a mean of 1.5 million.^[5]

Conservation

Queen Alexandra's birdwing (Ornithoptera alexandrae) of Papua New Guinea

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, colourful 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, 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 government of Papua New Guinea set up the Insect Farming and Trading Agency (IFTA) to regulate the exploitation and conservation of Queen Alexandra's birdwing and other valuable butterflies.

See also

• Insect ecology

References

1. W. S. Robinson, R. Nowogrodski & R. A. Morse. (1989). "Pollination parameters". Gleanings in Bee Culture. 117: 148–152.
2. S. E. McGregor (1976). Insect pollination of cultivated crop plants. USDA Agriculture Handbook 496, Washington, D.C.
3. Millennium Ecosystem Assessment, 2005. Ecosystems and Human Well-being: Biodiversity Synthesis. World Resources Institute, Washington, D. C.
4. P. S. Cranston & P. J. Gullan (2005). The Insects: An Outline of Entomology. Blackwell, Oxford. ISBN 1-4051-1113-5.
5. Stork, N. E.; McBroom, J; Gely, C; Hamilton, A. J. (2015). "New approaches narrow global species estimates for beetles, insects, and terrestrial arthropods". Proceedings of the National Academy of Sciences. 112: 201502408. doi:10.1073/pnas.1502408112. PMID 26034274.