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Bug of the Week is written by "The Bug Guy," Michael J. Raupp, Professor of Entomology at the University of Maryland.

Belizean sting - Slenderbrown scorpion, Centruroides gracilis

Who's that lurking in the corner of the bed frame?

During winter break, some adventurous students at the University of Maryland participated in a course that took them on a remarkable adventure to the rainforest in Belize to study Mayan culture and the fascinating creatures and plants in tropical ecosystems. By some strange coincidence, Bug of the Week happened to stow away on this tropical odyssey. In the next several episodes we leave behind the chill of the mid-Atlantic winter and head way south of the border for Bug of the Week.

Scary pinchers or pedipalps are used to capture prey.

After a long day of feeding mosquitoes and chasing Morelet's crocodiles, there is nothing like a little shut-eye in the bunkhouse. Unfortunately, one of our students climbed into his lower bunk bed and was surprised to see a rather impressive scorpion beneath the mattress of the upper bunk just a few inches above his head. In Belize the solitude of bedtime is often punctuated by several colorful and enthusiastic expletives describing the creatures found in the cabin. The exciting Slenderbrown scorpion is a regular visitor to cabins and outhouses at night and goes by many names including the Slenderbrown, Brown Bark Scorpion, or Alacran azul.

In a natural setting, I have seen it beneath the loose bark of a tree and under a log. This scorpion is found in Central and South America, the Caribbean, and in southern Florida. Scorpions are not insects. They belong to another part of the arthropod clan called arachnids and are relatives of spiders and ticks. The scary pinchers on the front end of the scorpion are its pedipalps. They are used for grasping and dismembering insects and spiders that comprise most of the scorpion's meals.


If this stinger gets you, you will be sending out an SOS to the world. 

The business end of the scorpion is the sting, an enlarged segment at the end of the scorpion’s tail that contains a venom gland and a needle-like poker to deliver the poison. The sting is used to immobilize and kill prey and also as a means of defense against larger animals. When scurrying across a floor or ceiling, the scorpion's sting is often curled up and over its back. Scorpions move surprisingly fast. The venom of the Slenderbrown scorpion carries a punch similar in toxicity to the sting of a honeybee or yellow jacket (see Feeling yellow ? Yellow Jackets, Vespula maculifrons ) but far less potent than the velvet ant (see Lady in red - Velvet ant, Dasymutilla occidentalis). Some relatives of the Slenderbrown scorpion are highly venomous and their stings can be fatal to humans. One courageous and somewhat impulsive student tested the potency of the sting when she grabbed a scorpion lurking over her bunk and hurled it out the door of her cabin. Her assessment of the experience: "It only hurt a little and that thing was really annoying me". You go girl.



Many thanks to Matt Tabisz for wrangling the scorpion in this Bug of the Week. For more information on scorpions, please visit the following web site.