Tobacco Hornworm (Manduca sexta) and the Parasite Wasp (Cotesia spp.)

The picture on the left is the tobacco hornworm (Manduca sexta) that infested my tomato plant.  The insect belong to Sphingidae family, commonly known as hawk moth.  The tobacco hornworms can be distinguished from the closely related tomato hornworms by their seven diagonal stripes versus eight v-shaped marking on the tomato hornworms.  The most striking feature of the hornworm is the thick pointing structure (or horn) located dorsally on the terminal abdominal segment.  On the back of the larvae, there are clusters of parasite wasp cocoons which has be infested the larvae and emerge from the skeleton.

This post, I am getting some close-up view of the tobacco hornworm and the parasite wasps under a stereo microscope.

Close-up of the tobacco hornworm

Mandible of the larvae (slightly out-of-focus are the thoracic legs)	Ocelli
Thoracic legs	The tip of the prolegs on abdomen.  Now, you know why it is so hard to remove the caterpillar from the tomato vine.  They are full of “claws”.
Spiracles	Another view of the spiracle (with 4x objective rather than 2x)
The spiracles and the lesions caused by the parasite wasps
The terminal segment of the abdomen.  The end is full of spikes.  That’s how they stick to the vine when you are trying to pull them off the vine.	The horn - “signature” of the tobacco hornworm.

The parasite Wasp

Day3 (8/29/2011): The cocoons of the parasite wasp at the dorsal of the tobacco hornworm (this picture was taken about 48 hour after we collected the hornworm)	Cut open the cocoon, there was a larvae inside
Continue to peel open the cocoon.  Here’s full view of the larvae.	Day 4 (8/30/2011): Just one day after I opened up the cocoon.  Apparently there was a big change inside of the larvae.  It’s already taking the shape of the wasp and with legs and pigmented eyes developed.
Day 5 (8/31/2011): Start to show darker pigmentation	Day 6 (9/1/2011): Even Darker pigmentation.  Still no movement
Day7 (9/2/2011): The appendages and antennas are starting to extend out and show some movement.  Occasionally, it would tweet its legs or antenna.  Wings are more visible now.	The wasp starting out with cutting a ring close to the top of the cocoon.
It did not cut all the way through.  It started to push when it the cut was about 90 percent of the circumference.	Continue to push.  First the antenna then the two front legs.
	Finally, completely came out of the cocoon.

 

The wasp that was removed from the cocoon did not survive.  Its wing did not extended out fully.  The picture on the left was another wasp that came out of cocoon on the same date. The pictures were combined using Microsoft image composite Editor since the antenna are very long and extended out of the field of view.

 

Video recording of the parasite wasp come out of the cocoon