The Trapdoor Spider hunts by lunging out from beneath the cap to grab passing prey and then pulling the catch into the burrow for consumption. I have always wanted to witness this spider in action. Having found evidence that the spider lived at Blue Jay Barrens, I was keen to find the living animal.
It crawled right out with no display of aggression.
It presents an odd appearance because it seems to have ten legs instead of eight. In this photo the spider is facing to the left. The two short projections are the chelicerae or jaws which terminate in fangs. Beside those, looking much like a first set of legs, are the pedipalps which seem to play a part in the mating process. The first real legs are found just behind the pedipalps.
My most useful identification guide, Spiders of North America – an Identification Manual by Ubick et.al., often requires magnified examination of specific spider parts that are obtained by dissecting a non-living specimen. I had no intention of sacrificing this individual, so I was hoping for the best with my photos. Fortunately, I was able to get some positive shots of a characteristic depression in the tibia of the third leg which identified this as a member of the genus Ummidia. The keys in the manual ended at genus with a note that it was widespread in the
The fangs can be seen to the left. The light patches on the abdomen are coverings over the lungs. Air enters the lung chamber by way of spiracles accessed through slits at the edge of the cover.
This area is very similar to that in which I found the 2009 burrow.
The inside of the burrow had definitely been reshaped and the outside edge had been reinforced by spider silk. Unfortunately, there was no sign of the spider. Hopefully, the spider found a more suitable location for a dwelling and dug its own burrow. I’m happy to have seen the live spider, but I’m still determined to see an occupied burrow in action.