''Spinochordodes tellinii'' is a parasitic nematomorph hairworm whose

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e develop in grasshoppers and crickets. This

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

is able to influence its host's behavior: once the parasite is grown, it causes its grasshopper host to jump into water, where the grasshopper will likely drown. The parasite then leaves its host; the adult worm lives and reproduces in water. ''S. tellinii'' does not influence its host to actively seek water over large distances, but only when it is already close to water. The microscopic larvae are ingested by their insect hosts and develop inside them into worms that can be three to four times longer than the host. The precise molecular mechanism underlying the modification of the host's behaviour is not yet known. A study in 2005 indicated that grasshoppers which contain the parasite

express Express, The Expresss or EXPRESS may refer to: Arts, entertainment and media Film * ''Express: Aisle to Glory'', a 1998 comedy short film featuring Kal Penn * ''The Express: The Ernie Davis Story'', a 2008 film starring Dennis Quaid * The Expre ...

, or create, different

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

s in their brains compared to uninfected grasshoppers. Some of these proteins have been linked to

neurotransmitter A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a Chemical synapse, synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell. Neurotra ...

activity, others to geotactic activity, or the body's response to changes in gravity. Furthermore, it appears that the parasite produces proteins from the Wnt family that act directly on the development of the central nervous system and are similar to proteins known from other insects, suggesting an instance of molecular mimicry. A similar parasitic worm is '' Paragordius tricuspidatus''.

References

External links

*
Video of ''Spinochordodes tellinii''
in which it causes a cricket to drown and then emerges from it. {{Taxonbar, from=Q1078014 Nematomorpha Parasitic protostomes Parasites of insects Suicide-inducing parasitism Animals described in 1888 Taxa named by Lorenzo Camerano