Hitchhikers

[Johnny_Johnson]

One day last week Mitchelle (my wife) was picking tomatoes and came across this tomato worm:

Here's a closer view:

The white thingies are cocoons of a Braconid wasp. The female wasp lays eggs under the skin of the caterpillar. After the eggs hatch the larvae feed on the tissue of the caterpillar until they are ready to pupate at which time they work their way to the surface and spin cocoons.

 

[Asher Kelman]

Johnny, this is fantastic.

Where is this taken and what is the set up? Also at what stage to the caterpillars die? Are they able to continue feeding for a whille? That at least would allow the developing wasp larva to get more food.

Is there only one egg per caterpillar?

Do the wasps husband their resources in the caterpillars and how choosy are they?

Asher

 

[Johnny_Johnson]

Johnny, this is fantastic.

Thanks Asher.

Where is this taken and what is the set up?

It was taken in our back yard here in White County, GA using the 5D and a Sigma 150/2.8 macro lens.

Also at what stage to the caterpillars die? Are they able to continue feeding for a whille? That at least would allow the developing wasp larva to get more food.

I think it must vary by caterpillar and how heavy the infestation. This particular one was still living but appeared to have quit feeding. I would guess that most live at least until the larva exit and spin the cocoon.

Is there only one egg per caterpillar?

Each of the cocoons in the first picture is the result of one egg. They may have been laid by multiple wasps in this case.

Do the wasps husband their resources in the caterpillars and how choosy are they?

I believe that the Tomato Horn Worm and Tobacco Horn Worm are the preferred hosts but they will utilize secondary hosts such as Catawba worms when the preferred hosts aren't available. I readily admit though that what little I do know about them comes from reading the results of Google searches over the past few days. <grin>

Later,
Johnny

 

[Asher Kelman]

I wonder whether the wasps sting? They seem to be interesting bio-control agents for pests! Although, I can't think of using them for protecting cabbages. The ecobioogy of this is fascinating.

Asher