1/4 Vernacular Name BUG, GIANT WATER (aka: toe biter; electric light bug) GEOGRAPHIC RANGE Across North America (Newfoundland to British Columbia), and south into northern Mexico. HABITAT Freshwater streams, especially in montane areas. They often inhabit intermittent streams, so they are isolated to individual rock pools during dry periods when streams do not exhibit overland flow. CONSERVATION STATUS • IUCN Status: Not Evaluated (2014). COOL FACTS • The sheer size of the insect and the unusual shape of the front legs help identify it. • TBB: This Bugger Bites. The giant water bug can inflict slightly painful bites to humans, but is not aggressive and does not bite unless handled carelessly. The bite is reported to include a minor poison like a bee sting and some digestive enzymes. • What caring animal dads can do for their kids? Unlike many insects whose eggs are abandoned by the adults, the giant water bug eggs are glued to the surface of the males’ tegmina (outer wings), and the adult males care for and protect the eggs until they hatch. Eggs removed from the males back do not hatch. • The male carries this load for the next month, periodically aerating the eggs and warding off parasites. • When the eggs get tripled in size after three weeks, the male stops eating altogether so as to avoid accidentally eating his new offspring. • Adults have two pairs of wings, but they rarely fly unless forced to by unfavorable water conditions or by lack of an adequate food supply. • Like terrestrial insects, these bugs respire through spiracles. When submerged for long periods of time, adult giant water bugs carry a temporary external air supply in the form of an air bubble. The bubble is in contact with the bug's spiracles located between their wings and Bug, Giant Water 2/4 their abdomen's upper surface. Nymphs hold their air store externally using a dense mat of hairs on the underside of the abdomen. • Voracious appetite: the giant water bug can catch and eat an animal 50 times its size, the equivalent of a person slurping up a whole elephant milkshake in one sitting! • The "electric light bug" name arises from their strong attraction to light bulbs. • Their "toe biter" name arises because that’s what they do in some streams. DIET • In wild: insects, small fish, small tadpoles, salamanders and will become cannibalistic when other food is scarce. • In Zoo: LONGEVITY • In wild: over 1 year. • In captivity: ENEMIES - DEFENSE • Enemies: birds, fish and other aquatic predators. • Defense: when sitting motionless, giant water bugs resemble dead leaves. This allows them to hide from both potential prey and possible predators. However, their best defense is to escape and hide when alarmed. MATING - CARE OF THE YOUNG • Mating season: the main mating season occurs during the summer, especially prior to and during the monsoons. • Courtship: males attract females by creating patterns of ripples in the water. • Mating: they then mate many times, the female laying 1-4 eggs after every copulation. Females lay their eggs (sometimes over 100) on the backs of their mates. • Parental Care: the father then cares for his brood until they hatch by carrying them to the surface periodically and performing a behavior called “brood pumping” underwater. He pumps water over the eggs to supply them with oxygen and occasionally raises them out of the water to prevent mold growth. • Hatching: eggs typically take 21-23 days to hatch. Once hatched, the nymphs develop through 5 instars before molting into adults. Newly hatched nymphs will eat just about anything, and must find suitable surfaces to hang on to for molting. • Adulthood: nymphs took about 60 days to progress through the five instars to adulthood. After the second instar, cannibalism seems to be far the most common cause of fatality among nymphs. SOCIAL INTERACTION • Adults do not kill one another unless severely starved (months). Although adults do not eat one another, adults will eat nymphs and nymphs will feed on one another. Bug, Giant Water 3/4 LIFE STYLE • Activity Period: diurnal. • Feeding: - giant water bugs are ambush hunters, lying motionless, resembling dead leaves and waiting for their prey. - they usually grab hold of a plant near the surface and stick their short breathing tube out of the water to allow them to breathe while waiting for prey. - with their powerful front legs, adults capture larger prey species by using their clawed front feet. - grasping and holding prey with their powerful forelegs, they pierce their prey with their sharp beak and secrete enzymes that dissolve the body tissues, thus allowing them to suck up the resulting liquid. • Both the large nymphs and adults will feign death when picked up, but they can stab suddenly with their beaks, injecting their anesthetic saliva used to subdue their prey. • They are active all year, but are most commonly seen in the late summer and early fall. At this time of year the adults are leaving the shallow ponds at night to look for deeper bodies of water where they can remain active throughout the winter under the ice. • They are often attracted to lights such as porch lights, where people find them the following morning. PHYSICAL • General Description: a large, flat, oval brown bug that looks like a cockroach. • Size: 1” – 1.5” long, .75” – 1” wide. Wingspan to 4”. • Color: brown. • Head has piercing, sucking mouth parts elongated into a beak-like structure designed for piercing and sucking. • Legs: the front legs are raptorial (grasping) to seize prey. Their other two pairs of legs are flattened and fringed with hair to increase their surface area. These legs are used like paddles for propulsion. • Snorkel: the posterior end of a giant water bug has two retractable, semi-cylindrical appendages which, when held together, form a breathing tube. • Wings: adults have two pairs of wings which overlap at the hind end of the abdomen, forming an X-like pattern. However, they rarely fly unless forced to by unfavorable water conditions or by lack of an adequate food supply. When in flight, air is exchanged through small openings of the respiratory system called spiracles. • They have one pair of tiny, almost inconspicuous antennae located snugly below their compound eyes. TAXONOMY Kingdom Animalia Phylum Arthropoda Class Insecta Order / Infraorder Hemiptera / Nepomorpha Family: Belostomatidae Genus / species Abedus herberti Bug, Giant Water 4/4 REFERENCES - Milne, Lorus, and Margery Milne. 2001. National Audubon Society Field Guide to Insects & Spiders. New York: Chanticleer Press, Inc. - IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. www.iucnredlist.org. Downloaded on 18 March 2014. - Abedus herberti: http://bugguide.net/node/view/255056 - http://www.americaninsects.net/ht/abedus-herberti.html - http://www.zoo.org/page.aspx?pid=1920 Prepared by: Dave Schaffer, docent Date: 03-18-2014 Photo by: Ltshears, Wikimedia & CC Map by: Dave Schaffer & Bob Sloane, docents Approved by: Date: Formatted by: Dave Schaffer, docent Date: .