''Abedus'' is a genus of

giant water bug Belostomatidae is a family of freshwater hemipteran insects known as giant water bugs or colloquially as toe-biters, Indian toe-biters, electric-light bugs, alligator ticks, or alligator fleas (in Florida). They are the largest insects in the ord ...

s (family Belostomatidae) found in freshwater habitats in southern United States, Mexico and Central America. Sometimes called ferocious water bugs, these brown insects typically are between long, although '' A. immaculatus'' only is about , making it the smallest North American belostomatid and possibly worthy of separation in its own genus. Otherwise the different ''Abedus'' species are very similar and can often only be separated with a microscope. They will bite in self-defense, which is painful but not dangerous.

Behavior

Members of this genus generally do not fly, and at least some species, including ''A. herberti'', have a greatly reduced flight apparatus and are completely flightless. Despite being essentially aquatic ''Abedus'' may travel some distance overland and have been known to abandon streams after heavy rainfalls, allowing them to avoid being swept along in flash floods.

Breeding

Giant water bugs exhibit male

parental care Parental care is a behavioural and evolutionary strategy adopted by some animals, involving a parental investment being made to the evolutionary fitness of offspring. Patterns of parental care are widespread and highly diverse across the animal ki ...

. In ''Abedus'' and other species in the subfamily Belostomatinae (but not subfamily Lethocerinae), the female glues the eggs onto the male's back and the male tends them until the eggs hatch. The eggs are initially yellow-white but gradually change to gray-brown. They can be quite large compared to the size of the adult; in the up to ''A. herberti'' of highland streams in

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

and northwestern Mexico each egg can measure as much as when fully developed. After hatching, the

nymphs A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are ...

go through five

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ...

stages before adulthood. Because of the unusual breeding behavior, especially ''A. herberti'' is often displayed in zoos, sometimes together with the

sunburst diving beetle ''Thermonectus marmoratus'' is a relatively colorful North American species of diving beetle known by the common names sunburst diving beetle and spotted diving beetle. The behavior of this diving beetle has been compared to a scuba diver, sinc ...

. These two species also occur together in the wild.

Feeding

''Abedus'' are

sit-and-wait predator Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey ...

s that catch small animals, especially invertebrates such as other aquatic insects and snails, but also small vertebrates such as young fish and

tadpole A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found ...

s. Small and medium-sized prey items are caught with their strong front legs and stabbed with the

proboscis A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elong ...

, which injects a saliva that both incapacitates the prey and dissolves it. The largest food category (in ''A. herberti'', animals or more in length) are mostly

scavenge Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding b ...

d. The only prey they regularly catch alive (not just scavenge) in the largest category is nymphs of their own species. Adults are generally highly

cannibalistic Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is well documented, bo ...

towards their nymphs and older nymphs often eat younger; adults however only rarely cannibalize other adults.

Species

List of species:
Subgenus ''Abedus'' *'' Abedus breviceps'' Stål, 1862 *'' Abedus ovatus'' Stål, 1862 *'' Abedus parkeri'' Menke, 1966 Subgenus ''Deinostoma'' *'' Abedus decarloi'' Menke, 1960 *'' Abedus dilatatus'' (Say, 1832) *'' Abedus herberti'' Hidalgo, 1935 *'' Abedus immensus'' Menke, 1960 *''

Abedus indentatus ''Abedus indentatus'' is a species of giant water bug in the family Belostomatidae Belostomatidae is a family of freshwater hemipteran insects known as giant water bugs or colloquially as toe-biters, Indian toe-biters, electric-light bugs, al ...

'' (Haldeman, 1854) *'' Abedus stangei'' Menke, 1960 Subgenus ''Microabedus'' *'' Abedus immaculatus'' (Say, 1832) Subgenus ''Pseudoabedus'' *'' Abedus signoreti'' Mayr, 1871 *'' Abedus vicinus'' Mayr, 1871

References

{{Taxonbar, from=Q4666482 Nepomorpha genera Belostomatidae