Rigor Vitae: Life Unyielding

Sunday, April 01, 2007


I'm devoting today's post to a very unusual arthropod that's rather common in the immediated vicinity of my home, although I've never seen it anywhere else. The Assassin Dock (Lappazoon sarcophagus) displays an extreme sexual dimorphism: the small, flying males live but a few days, fluttering weakly upon the breeze. The much larger females are sessile, saprophagic, plant-like creatures anchored to the soil by their rootlike heads.
Every other year, these females, which can reach over a meter in height, "flower," giving rise to numerous burr-like sexual bodies. Attached weakly to their stalks, the mature sexual bodies break away if snagged on the fur or feathers of a passing animal, and begin growing "feeding tubes," which pierce the skin of the victim, secreting a potent toxin, while extracting nutrients. The injection kills the host in a few days, and the sexual body, after being fertilized, scatters eggs about the corpse. The larval Assassin Docks feed on the flesh of their host, and overwinter as cysts. Most larvae metamorphose into mature males the following summer. Female larvae live in the enriched soil for two seasons before metamorphosing, and "sprouting" from the ground.
illustration: "ASSASSIN DOCK" (2004) watercolor 24" x 18"


Blogger T. Beth said...

LOL, I love it! ;-)

2:24 PM  
Blogger burning silo said...

Wow, that's a wonderful poster of the life cycle of the Assassin Dock -- in fact, it's the nicest one I've ever seen. Loved it! ;-}

4:23 AM  
Blogger lisa said...

Wow...thanks for this post, very interesting! Exactly how large a "host" will this thing kill?

12:38 PM  
Blogger Carel Brest van Kempen said...

Beth: Thanks! Although Assassin Docks haven't been documented outside of northern Utah, there have been unconfirmed reports of them in your area. This painting was originally done for the "Imagine That!" exhibition at the Arizona/Sonora Desert Museum in '04.
Bev: Thanks! I'm surprised that more posters haven't been created of this fascinating and little-known creature.
Lisa: The toxins seem to be quite potent, and could conceivably kill a human. Fortunately, like I said, I've only seen them in the immediate vicinity of my own home.

3:24 PM  
Blogger Patrick B. said...

I hear they only occur in the presence of greenish smoke and loads of alcohol. :)

10:52 AM  
Blogger Karen said...

We have something similar where I live. The problem is, people actually go to specialty "nurseries", pick one out (the larger ones are most popular), and put them inside their homes!

Fortunately, these creatures don't kill right away, so there is a chance of survival. However, they can, and do cause their victims to become sedentary and susceptible to infections, such as believing everything the media says.

Excellent poster, by the way, and a fine public service announcement.

8:46 AM  
Anonymous Anonymous said...

what a great site. your assasin dock reminds me of leo leonni's "parallel botany". your paintings are inspiring to my son as well!

8:14 PM  
Anonymous Anonymous said...


11:26 AM  

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