Aninsectivoreis acarnivorousanimal or plant that eatsinsects.[1]An alternative term isentomophage,[2]which can also refer to thehuman practice of eating insects.
The first vertebrate insectivores wereamphibians.When theyevolved400 million years ago, the first amphibians werepiscivores,with numerous sharp conical teeth, much like a moderncrocodile.The same tooth arrangement is however also suited for eating animals withexoskeletons,thus the ability to eat insects is an extension of piscivory.[3]
At one time, insectivorousmammalswerescientifically classifiedin anordercalledInsectivora.This order is now abandoned, as not all insectivorous mammals are closely related. Most of the Insectivorataxahave been reclassified; those that have not yet been reclassified and found to be truly related to each other remain in the orderEulipotyphla.
Although individually small, insects exist in enormous numbers. Insects make up a very large part of the animal biomass in almost all non-marine, non-polar environments. It has been estimated that the global insect biomass is in the region of 1012kg (onebilliontons) with an estimatedpopulationof 1018(one billion billion, orquintillion) organisms.[4]: 13 Many creatures depend on insects as their primary diet, and many that do not (and are thus not technically insectivores) nevertheless use insects as aproteinsupplement, particularly when they are breeding.[5]
Examples
editExamples of insectivores include different kinds of species ofcarp,opossum,frogs,lizards(e.g.chameleons,geckos),nightingales,swallows,echidnas,[6]numbats,anteaters,armadillos,aardvarks,pangolins,aardwolfs,[7]bats,andspiders.Even large mammals are recorded as eating insects;[5]thesloth bearis perhaps the largest insectivore. Insects also can be insectivores; examples aredragonflies,hornets,ladybugs,robber flies,andpraying mantises.[8]: 31 Insectivory also features to various degrees amongstprimates,such asmarmosets,tamarins,tarsiers,galagosandaye-aye.[9][10]: 56–57 There is some suggestion that the earliest primates werenocturnal,arborealinsectivores.[11]
Insectivorous plants
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Insectivorous plantsare plants that derive some of theirnutrientsfrom trapping and consuming animals orprotozoan.The benefit they derive from their catch varies considerably; in some species, it might include a small part of their nutrient intake and in others it might be an indispensable source of nutrients. As a rule, however, such animal food, however valuable it might be as a source of certain critically important minerals, is not the plants' major source ofenergy,which they generally derive mainly from photosynthesis.[12]: 14
Insectivorous plants might consume insects and other animal material trapped adventitiously. However, most species to which such food represents an important part of their intake are specifically, often spectacularly, adapted to attract and secure adequate supplies. Their prey animals typically, but not exclusively, compriseinsectsand otherarthropods.Plants highly adapted to reliance on animal food use a variety of mechanisms to secure their prey, such as pitfalls, sticky surfaces, hair-trigger snaps, bladder-traps, entangling furriness, and lobster-pot trap mechanisms.[12]: 14–17 Also known ascarnivorous plants,they appear adapted to grow in places where the soil is thin or poor in nutrients, especiallynitrogen,such as acidicbogsand rock outcroppings.[12]: 13
Insectivorous plants include theVenus flytrap,several types ofpitcher plants,butterworts,sundews,bladderworts,thewaterwheel plant,brocchiniaand many members of theBromeliaceae.The list is far from complete, and some plants, such asRoridulaspecies, exploit the prey organisms mainly in a mutualistic relationship with other creatures, such as resident organisms that contribute to the digestion of prey. In particular, animal prey organisms supply carnivorous plants with nitrogen, but they also are important sources of various other soluble minerals, such as potassium and trace elements that are in short supply in environments where the plants flourish. This gives them a decisive advantage over other plants, whereas in nutrient-rich soils they tend to be out-competed by plants adapted to aggressive growth where nutrient supplies are not the major constraints.
Technically these plants are not strictly insectivorous, as they consume any animal that they can secure and consume; the distinction is trivial, however, because not many primarily insectivorous organisms exclusively consume insects. Most of those that do have such a restrictive diet, such as certainparasitoidsandhunting wasps,are specialized to exploit particular species, not insects in general. Indeed, much as large mantids and spiders will do, the larger varieties of pitcher plants have been known to consumevertebratessuch as small rodents and lizards.[12]: 13 Charles Darwinwrote thefirst well-known treatise on carnivorous plantsin 1875.[13]
See also
edit- Entomophagy
- Consumer-resource systems
- Insectivora
- List of feeding behaviours
The dictionary definition ofinsectivoreat Wiktionary
References
edit- ^Miller, George A. (2009)."Article forinsectivorous".WordNet.Princeton University.Retrieved1 April2010.
- ^Gullan, P.J.; Cranston, P.S. (2005).The Insects: An outline of entomology.Malden, MA:Blackwell Publishing.p. 455.ISBN978-1-4051-1113-3.
- ^Sahney, S.; Benton, M.J.; Falcon-Lang, H.J. (2010)."Rainforest collapse triggered Pennsylvanian tetrapod diversification in Euramerica"(PDF).Geology.38(12):1079–1082.Bibcode:2010Geo....38.1079S.doi:10.1130/G31182.1.
- ^Dudley, Robert (2002)."Flight and the Pterygote Insecta".The Biomechanics of Insect Flight: Form, function, evolution.Princeton University Press.pp.3–35.ISBN978-0-691-09491-5.
- ^abWhitney, Stephen R.; Sandelin, R. (2004).Field Guide to the Cascades & Olympics.The Mountaineers Books. p. 317.ISBN978-0-89886-808-1.Retrieved1 April2010.
- ^""Long-beaked Echidna (Zaglossus bruijni)" (entry) ".animalinfo.org.West of Scotland & Ayr Group.Retrieved1 April2010.
- ^Holekamp, Kay E."Aardwolf (Proteles cristata) ".animalinfo.org. Archived fromthe originalon 17 April 2010.Retrieved1 April2010.
- ^Hill, Dennis S. (1997).The Economic Importance of Insects.Springer. p. 198.ISBN978-0-412-49800-8.Retrieved1 April2010.
- ^Stetoff, Rebecca (2006).The Primate Order.Marshall Cavendish. p. 92.ISBN978-0-7614-1816-0.
- ^Jones, S.; Martin, R.; Pilbeam, D., eds. (1994).The Cambridge Encyclopedia of Human Evolution.Cambridge, UK: Cambridge University Press.ISBN0-521-32370-3.
- ^Weiss, M.L.; Mann, A.E. (1985).Human Biology and Behaviour: An anthropological perspective.Boston, MA: Little Brown & Co.ISBN0-673-39013-6.
- ^abcdSlack, Adrian; Gate, Jane (2000).Carnivorous Plants.MIT Press.ISBN978-0-262-69089-8.
- ^Darwin, C.(1875).Insectivorous Plants.London, UK: John Murray. Archived fromthe originalon 23 September 2006.