EPOW - Ecology Picture of the Week

Explanation:  Watch where you step.  You are on the remote banks of the Ubangi River, a huge tributary of the Congo River, in western Democratic Republic of the Congo smack dab on the equator (zero degrees latitude).  It is night and by the light of your torch you nearly step on this monster of a water bug, measuring easily 10 cm (4 inches) long.  Things seem to grow big in the African tropics!

This is a member of the giant water bug insect family Belastomatidae, the largest of the "true bugs" (family Hemiptera).  It is a predator of insects, fish, tadpoles, small frogs, and other small vertebrates.  This one is at least twice the length and far more massive than its Lethocerus cousins found in the U.S.  It also dwarfs Water Boatmen.  

Females lay their eggs on vegetation or on the back of the male which carries the eggs until they hatch.  Such exclusive gender care of offspring is rare in animals but has arisen independently in 13 arthropod taxa (Tallamy 2001).  

Giant Water Bugs and Creeping Water Bugs (in the related family Naucoridae, also in order Hemiptera) presumably are vectors for the disease brucelosis in Africa.  Brucelosis is a leprosy-like affliction that attacks ungulates.  

Giant Water Bugs breath through their ... hind end.  From the water, they raise the tip of the abdomen into the air and extend two tail-like breathing tubes.

Don't pick it up.  Giant Water Bugs have piercing mouth parts.  They can bite badly and inject an anesthetic saliva used to subdue prey.  In Florida, they are called "toe biters" or "alligator bugs."  Guess why.  They are attracted to bright lights at night and are also sometimes called "electric light bugs."  

Giant Water Bugs and Creeping Water Bugs can be problems in swimming areas.  But they are considered a food delicacy in parts of China.  

Acknowledgment:  Many thanks to aquatic entomologist Ken Cummins for the identification and for some of the information presented on this page.

Information:
     Tallamy, D. W.  2001.  Evolution of exclusive parental care in arthropods.  Annual Review of Entomology 46:139-165.
     Smith, R. L., 1997. Evolution of paternal care in giant water bugs (Heteroptera: Belastomatidae). In The Evolution of Social Behavior in Insects and Arachnids, J. C. Choe & B. J. Crespi, eds. Cambridge Univ. Press. Pp. 116-149.