• 3 genera and 32 species in North America

Phylum: Arthropoda
Class: Insecta
Order: Hemiptera
Family: Notonectidae

Identification Tips:

• Length 5-17 mm
• Rear legs greatly elongated with 'paddles' made of hairs at the ends
• Swims upside down most of the time; strong swimmer
• Lighter coloured on back than front

Life History:

• Most common in small ponds or near shores of lakes
• Found in quiet water of all aquatic habitats, including brackish water, sewage lagoons, ditches, and hotsprings
• Prey on small insects, crustaceans, snails and sometimes fish fry and tadpoles
• Hold prey with spiny front legs, pierce it with beak and sucks our bodily juices
• Can inflict painful bites on humans
• Breathe air, carrying air bubble in troughs on side of abdomen while diving
• Adults are strong flyers and may disperse considerable distances
• Usually 2 generations per year
• Lay eggs on submerges plants or rocks

Very Sensitive Somewhat Sensitive Facultative Somewhat Tolerant Very Tolerant

Primary Information Source:
Voshell, J. Reese. 2002. A Guide to Common Freshwater Invertebrates of North America. McDonald and Woodward Publishing Company. Blacksburg, Virginia.