Alienesque tendencies of the insect world

This video shows how a Jewel wasp continues it’s existence through manipulation of cochroaches.


It must have taken parasitic wasps millions of years to co-evolve to such precision with their prey/host!

Here are some others I’ve found: … PL&index=4 … re=channel gulp

Those were some interesting videos Pan. It does make me wonder if the movie “Alien” may have been inspired by suchh creatures. Where I live there are insects that are preyed on closely in the same manner called ‘Cicadas’ by a wasp called ‘Cicada Killers’. I have sort of a cheesy video about them but it gets the point across:


Biotrophic parasitism is a common mode of life that has arisen independently many times in the course of evolution. Depending on the definition used, as many as half of all animals have at least one parasitic phase in their life cycles, and it is also frequent in plants and fungi. Moreover, almost all free-living animals are host to one or more parasite taxa.

Parasites evolve in response to defense mechanisms of their hosts. Examples of host defenses include the toxins produced by plants to deter parasitic fungi and bacteria, the complex vertebrate immune system, which can target parasites through contact with bodily fluids, and behavioural defenses. (An example of the latter is the avoidance by sheep of open pastures during spring, when roundworm eggs accumulated over the previous year hatch en masse.) As a result of these and other host defenses, some parasites evolve adaptations that are specific to a particular host taxon and specialize to the point where they infect only a single species.

Such narrow host specificity can be costly over evolutionary time, however, if the host species becomes extinct. Thus, many parasites are capable of infecting a variety of host species that are more or less closely related, with varying success.

Host defenses also evolve in response to attacks by parasites. Theoretically, parasites may have an advantage in this evolutionary arms race because of their more rapid generation time. Hosts reproduce less quickly than parasites, and therefore have fewer chances to adapt than their parasites do over a given span of time.

In some cases, a parasite species may coevolve with its host taxa. In theory, long-term coevolution should lead to a relatively stable relationship tending to commensalism or mutualism, in that it is in the evolutionary interest of the parasite that its host thrives.

A parasite may evolve to become less harmful for its host or a host may evolve to cope with the unavoidable presence of a parasite to the point that the parasite’s absence causes the host harm. [eventual endosymbiosis?]

Parasites inhabit hosts, which represent mobile habitat patches with dynamic spatial relationships. There is no true “mainland” other than the sum of hosts (host population), so parasite component communities in host populations are metacommunities.

Parasites infect hosts that exist within their same geographical area (sympatric) more effectively. This phenomenon supports the “Red Queen hypothesis - which states that interactions between species (such as host an parasites) lead to constant natural selection for adaptation and counter adaptation.”

Braconid parasite wasps and their caterpillar hosts form a unique host-parasite model: the wasps lay their eggs inside the caterpillars and simultaneously inject some viral particles to get around the host’s defenses and control its physiology. The genes from these viral particles have now been identified in the wasp’s own genome…

The results indicate that the ancestor of the braconid wasps integrated the genome of a nudivirus into its own genome. Although these genes continue to produce viral particles, the particles now deliver the wasp’s own virulence genes into the parasitized host.

The wasps have therefore “domesticated” a virus to turn it into a vector for transferring their genes. Study of this phenomenon is particularly interesting for the development of new vectors for gene therapy, a therapeutic technique that consists of inserting genes into an individual’s cells or tissues to treat an illness.

Genes are delivered using a deactivated virus as a vector. The particles from parasite wasps are in fact true “natural” vectors, selected over 100 million years to perform this function and capable of transferring large quantities of genetic material (more than 150 genes). … 100425.htm

Most insects are such vile-looking creatures - I don’t mind ones that glow.

Concerning parasites the host interesting ones are those that alter the behaviour of the host. Many know Dicrocoelium dendriticum (lancet liver fluke), forcing its ant host to clamp itself to the tip of grass blades, where a grazing mammal (cattle normally) might eat it.
But what about Toxoplasma gondii species? Those protozoans alter the behaviour of rats. The parasite lives in the gut of cats, shedding eggs that can be picked up by rats and other rodents. Toxoplasma forms cysts throughout its intermediate host’s body, including the brain. The rats seem to have a normal life, healthy and fertile. The only difference is that they are more likely to get themselves killed. The scent of a cat don’t make them anxious, and they went about their business as if nothing was bothering them. Then they are caught easily and the cycle is perfect.
The big question is, as rat and human brains are not that different, and Toxoplasma can anyway infect humans (normally harmless, but toxoplasmosis can be dangerous if a woman is pregnant or the immune system is weak): Does Toxoplasma change human behaviour too? O:)
There was (or still is, I don’t know) an exciting discussion on this issue.

Have a look here or here: (from where I took over some of the sentences :wink: