trypophobia

Fear of holes.

(Greek, trypo- (boring holes)  + phobia,  (fear))

More specifically, the term, which was coined around 2005, applies to feelings of revulsion, disgust, and fear at the images of clusters of holes.

"I can’t really face small, irregularly or asymmetrically placed holes, they make me like, throw up in my mouth, cry a little bit, and shake all over, deeply."
--a respondent to a University of Essex study in 2012

The typical example cited is a lotus pod, but reports from those who claim this phobia cite images of clustered holes in cake or pancake batter, chocolate, honeycomb, skin*, meat, wood, plants, coral, and sponges as triggers.

Researchers at the Centre for Brain Science at the University of Essex analyzed images found on the Web of such clusters of holes, and found that they all possessed properties characteristic of images that most people find uncomfortable to view ("comparatively high contrast energy at midrange spatial frequencies.") They also found that the patterning on poisonous animals, such as the deathstalker scorpion, the king cobra, the poison dart frog, the pufferfish, and the blue-ringed octopus had this same characteristic. Thus, they suggest that coincidentally, those who are disturbed by images of clusters of holes are exhibiting a visual aversion that has survival value, from an evolutionary perspective.

* I don't think you have to suffer from this phobia to have an aversion to some of the weird photoshopped images out there: one, two.

Sources:
Jennifer Abbasi, "Is Trypophobia a Real Phobia?" Popular Science. July 25, 2011. http://www.popsci.com/trypophobia (accessed September 11, 2013)
Julie Beck, "Who's Afraid of a Cluster of Holes? 16 Percent of People." The Atlantic. September 11, 2013. http://www.theatlantic.com/health/archive/2013/09/who-s-afraid-of-a-cluster-of-holes-16-percent-of-people/279524/ (accessed September 11, 2013)
Geoff G. Cole and Arnold J. Wilkins, "Fear of Holes." Psychological Science 0956797613484937, first published on August 27, 2013 doi:10.1177/0956797613484937
Trypophobia.com