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Sphex

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Sphex
Sphex pensylvanicuson akatydid
Scientific classificationEdit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Infraorder: Aculeata
Superfamily: Apoidea
Family: Sphecidae
Subfamily: Sphecinae
Genus: Sphex
Linnaeus,1758
Type species
Sphex flavipennis
Species

More than 130; see text

Waspsof the genusSphex(commonly known asdigger wasps) arecosmopolitanpredatorsthat sting and paralyze prey insects.Sphexis one of many genera in the old digger wasp familySphecidae(sensu lato), though most apart from the Sphecinae have now been moved to the familyCrabronidae.[1]There are over 130 knownSphexspecies.

Behaviour

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In preparation for egg laying, they construct a protected "nest" (some species dig nests in the ground, while others use pre-existing holes) and then stock it with captured insects. Typically, the prey are left alive, butparalyzedbywasptoxins. The wasps lay their eggs in the provisioned nest and the wasplarvaefeed on the paralyzed insects as they develop.

The great golden digger wasp (Sphex ichneumoneus) is found in North America. The developing wasps spend the winter in their nest. When the new generation of adults emerge, they contain the genetically programmed behaviors required to carry out another season of nest building. During the summer, a female might build as many as six nests, each with several compartments for her eggs. The building and provisioning of the nests takes place in a stereotypical, step-by-step fashion.

Sphexhas been shown, as in someJean-Henri Fabrestudies,[2]not to count how many crickets it collects for its nest. Although the wasp instinctively searches for four crickets, it cannot take into account a lost cricket, whether the cricket has been lost to ants or flies or simply been misplaced.Sphexdrags its cricket prey towards its burrow by the antennae; if the antennae of the cricket are cut off, the wasp would not think to continue to pull its prey by a leg.

The navigation abilities ofSphexwere studied by the ethologistNiko Tinbergen.[3]Richard DawkinsandJane Brockmannlater studied female rivalry over nesting holes inSphex ichneumoneus.[4]

Use in philosophy

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Some writers in thephilosophy of mind,most notablyDaniel Dennett,have citedSphex's behavior for their arguments about human and animalfree will.[5]

SomeSphexwasps drop a paralyzed insect near the opening of the nest. Before taking provisions into the nest, theSphexfirst inspects the nest, leaving the prey outside. During the inspection, an experimenter can move the prey a few inches away from the opening. When theSphexemerges from the nest ready to drag in the prey, it finds the prey missing. TheSphexquickly locates the moved prey, but now its behavioral "program" has been reset. After dragging the prey back to the opening of the nest, once again theSphexis compelled to inspect the nest, so the prey is again dropped and left outside during another stereotypical inspection of the nest. Thisiterationcan be repeated several times without theSphexchanging its sequence; by some accounts, endlessly. Dennett's argument quotes an account ofSphexbehavior fromDean Wooldridge'sMachinery of the Brain(1963).[6]Douglas Hofstadter[7]andDaniel Dennett[8]have used this mechanistic behavior as an example of how seemingly thoughtful behavior can actually be quite mindless, the opposite of free will (or, as Dennett described it,sphexishness).

Philosopher Fred Keijzer challenges this use ofSphex,citing experiments in which behavioral adaptations are observed after many iterations. Keijzer sees the persistence of theSphexexample in cognitive theory as an indication of its rhetorical usefulness, not its factual accuracy.[9]Keijzer also noted that repeated inspection of a disturbed nest may very well be an adaptive behavior, thus diminishing the aptness of Hofstadter's metaphor.[9]

Species

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Sphex argentatus
Sphex funerariuswith prey

The genusSphexcontains 132 extant species:[10]

Fossil Species

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References

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  1. ^Pulawski, Wojciech J. (25 April 2021) [2014]."Family Group Names and Classification: and taxa excluded from Sphecidae sensu lato"(PDF).California Academy of Sciences.Retrieved14 January2022.
  2. ^Fabre, J.H. (1915/2001).The hunting wasps.New York: Dodd, Mead and Company.
  3. ^Tinbergen, N. (1974).Curious naturalists(2nd Ed). Harmondsworth: Penguin.
  4. ^Dawkins, Richard;Brockmann, H. Jane(1980)."Do Digger Wasps Commit the Concorde Fallacy?"(PDF).Animal Behaviour.28(3): 892–896.doi:10.1016/s0003-3472(80)80149-7.S2CID54319297.Retrieved19 July2015.
  5. ^Dennett, Daniel (1973). "Mechanism and responsibility". In T. Honderich (Ed.),Essays on freedom of action.London: Routledge.
  6. ^Dean Wooldridge (1963).The Machinery of the Brain.McGraw-Hill
  7. ^Hofstadter, Douglas (1985). "On the seeming paradox of mechanizing creativity". InMetamagical themas.Penguin. pp. 526–546.
  8. ^Dennett, Daniel (1973). "Mechanism and responsibility". In T. Honderich (Ed.),Essays on freedom of action.London: Routledge.
  9. ^abKeijzer, Fred."The Sphex story: How the cognitive sciences kept repeating an old and questionable anecdote"(PDF).Retrieved19 July2015.
  10. ^Pulawski, Wojciech (11 October 2021)."Sphex"(PDF).California Academy of Sciences.
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Look upSphex,sphexish,orsphexishnessin Wiktionary, the free dictionary.
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