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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Fri Jun 19, 2009 9:13 pm 
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Its a form of parasitism.

Parasitic wasps (Braconidae) will lay an egg inside of the caterpillar. The larvae that hatch will eat the caterpillar from the inside and then pupate in a cocoon on the outside of the caterpillar. This is the visible white cocoons on the caterpillar.

:hmz: Aids. Has this anything to do with the number of larvae?

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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Sat Jun 20, 2009 8:11 am 
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The correlation between Braconid parasite wasps, and the caterpillars and injecting viral particles to obtain control of its physiology.

Parasite Wasps Have Practiced Gene Therapy For A Hundred Million Years

ScienceDaily (Feb. 16, 2009) — 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 by a team at the Institut de recherche sur la biologie de l'insecte (CNRS/Université François-Rabelais Tours), in collaboration with a laboratory at University of Berne and Genoscope d'Evry.

These genes came from a virus captured by a common ancestor of these wasps 100 million years ago. These results, published in Science 13 February 2009, could provide new means of designing transfer vectors for gene therapy.

Wasps of the family Braconidae reproduce by laying their eggs in caterpillars, which then serve as food for the developing wasp larvae (1). However, the body of a caterpillar is a hostile environment, with an efficient defense system that forms a capsule of immune cells around foreign objects. To get around these defenses, when the wasp lays her eggs in the caterpillar, she also injects some special particles made in her ovaries. These particles enter the caterpillar's cells where they induce immunosuppression and control development, allowing the wasp larvae to survive.

Although many examples of symbiotic bacteria are known, the present case of a parasitic species using a virus to control its host's physiology is unique. To improve our understanding of the phenomenon, researchers at the Institut de recherche sur la biologie de l'insecte (CNRS/Université François-Rabelais Tours) are studying these viral particles in detail. In previous work, they had questioned whether the particles were truly viral, as they found that the particle genome lacked the necessary machinery for replication usually found in viruses.

Their most recent findings, published in Science, show that the particles are indeed viral in nature, but that their components lie within the wasp's own genome. More that twenty different genes coding for characteristic components of nudiviruses – insect viruses often used in biological pest control – are expressed in the wasps' ovaries. Furthermore, these genes are conserved in the different kinds of wasp that make these particles.

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). Understanding how they work could therefore be very useful for the design of new therapeutic vectors
(and thus as a possible cure for AIDS?)

The wasp pierces the caterpillar's skin with a sort of stylet, called an auger. It then lays its eggs inside the body , and the wasp larvae then develop in the caterpillar's blood, on which they feed.

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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Sat Jun 20, 2009 9:43 am 
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Great team effort!! Imberbe, you got two of three correct, and Elzet finished the task. (Thanks for posting so much of the article...I wondered how you were going to condense it. But, yes, the suppression of the immune system in the host via a virus was my intent.)

Now, as a team, you two can decide who posts next. Thanks!


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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Sat Jun 20, 2009 8:38 pm 
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Elzet, thanks for the article. Quite interesting. Africat, thanks for asking such interesting questions!

Imberbe, as always... :clap:

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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Mon Jun 22, 2009 1:18 am 
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Gee, thanks guys ... you are so kind! :whistle:

Have another look at the photo. How many eggs did the wasp lay inside of the caterpillar, and why do you say so?

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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Mon Jun 22, 2009 5:56 pm 
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Hi Imberbe, not gonna count the larvea on the outside - but five/six of the red/brown dots on the top of the caterpillar depicts damage by larvea that has gorged their way through to the outside...

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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Tue Jun 23, 2009 5:34 am 
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Millions? :lol:

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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Sat Jul 04, 2009 11:19 am 
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Not sure about this, Imberbe, but will venture a guess...

I can count 25 larva, so the wasp must have laid 25 or more eggs, but I have no idea what percentage lived and developed to the larva stage, or how to know that.

Also, I only photographed that one side of the caterpillar, so have no way to tell how many are not visible on the other side....so what nugget of info. do you have up your sleeve, Imberbe?


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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Sat Jul 04, 2009 12:54 pm 
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Africat...I concur,...what nugget of info do you have up your sleave
Imberbe? :hmz:

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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Sat Jul 04, 2009 1:34 pm 
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Imberbe wrote:
Parasitic wasps (Braconidae) will lay an egg inside of the caterpillar. The larvae that hatch will eat the caterpillar from the inside and then pupate in a cocoon on the outside of the caterpillar. This is the visible white cocoons on the caterpillar.


One egg, many larvae.... cause you said so, Imberbe... :lol:

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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Sat Jul 04, 2009 1:37 pm 
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Further to the above...

Life Cycle:

Biology and details of development vary with species. Adult wasps emerge from pupae and females seek suitable host insects into or on which to lay eggs singly or in clusters. Usually, a larva hatches from an egg and develops through several stages (instars) before forming a pupa. However, some parasitic wasps, such as Copidosoma spp. (Chalcidoidea, Encyrtidae), undergo a process called polyembryony, whereby an egg inserted into a host divides and gives rise to hundreds of larvae. Most parasitic species have high reproductive capacity and develop rapidly. Several generations can sometimes develop during a single generation of the host, although some species have only a single generation per year.

:lol: :lol:

http://insects.tamu.edu/fieldguide/cimg329.html

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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Sat Jul 04, 2009 3:01 pm 
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I think you need to know both the caterpillar (butterfly) species, as well as the parasitic wasp species, to discern the precise life cycle involved....???


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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Sun Jul 12, 2009 6:02 pm 
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Imberbe,
This one's been in the queue for many moons...care to help us out?
I hope we don't make you sorry you let us know you're back! Welcome home.


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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Sun Jul 12, 2009 6:17 pm 
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:lol:

Sorry for leaving you all ... but hey ... KNP! :wink:

Elzet is quite correct. 8)

The wasps of the Braconidae family will only lay one egg inside of the caterpillar. The egg will divide in to several eggs. Through some yet undiscovered wonder of nature the number and divisions of the egg is exactly tuned to the species and age of the caterpillar and its projected growth potential. :shock: This gives the maximum result for the minimum input! In other words ... reproductive success!

Nature is truly amazing ...

I don't think Elzet is around ... so Africat ... you're IT! :wink:

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 Post subject: Re: Insect Quiz (RV)
Unread postPosted: Mon Jul 13, 2009 2:32 pm 
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Every man's dream...every woman's nightmare?

I'm a male insect that has circumvented a number of roadblocks to mating at will, i.e.: mating plugs used in several species, female resistance ("the 'ol headache ruse"), and wasted courtship time (so much for foreplay)...what insect am I, and what tactic do I employ?


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