Lethocerus

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Ecdysozoa
Cladus: Panarthropoda
Phylum: Arthropoda
Subphylum: Hexapoda
Classis: Insecta
Cladus: Dicondylia
Subclassis: Pterygota
Cladus: Metapterygota
Infraclassis: Neoptera
Cladus: Eumetabola
Cladus: Paraneoptera
Superordo: Condylognatha
Ordo: Hemiptera
Subordo: Heteroptera
Infraordo: Nepomorpha
Superfamilia: Nepoidea

Familia: Belostomatidae
Subfamilia: Lethocerinae
Genus: Lethocerus

Species (22): L. americanus – L. angustipes – L. annulipes – L. bruchi – L. camposi – L. colossicus – L. cordofanus – L. delpontei – L. dilatus – L. distinctifemur – L. grandis – L. indicus – L. insulanus – L. jimenezasuai – L. maximus – L. mazzai – L. medius – L. melloleitaoi – L. oculatus – L. patruelis – L. truxali – L. uhleri
Name

Lethocerus Mayr, 1853

Synonyms

Amorgius Stål, 1866
Iliastus Gistel, 1847

References

Cianferoni, F.; Nardi, G. 2013: Lethocerus patruelis (Stål, 1855) in Italy: a recent introduction or a natural westward spread? (Hemiptera: Heteroptera: Nepomorpha: Belostomatidae). Zootaxa 3664(1): 78–84. DOI: 10.11646/zootaxa.3664.1.6 Reference page.

Links

Lethocerus Mayr, 1853 – Taxon details on Integrated Taxonomic Information System (ITIS).
Lethocerus – Taxon details on National Center for Biotechnology Information (NCBI).
Lethocerus Mayr 1853 Taxon details on Fauna Europaea

Vernacular names
English: Giant Water Bugs
日本語: タガメ属

Lethocerus is a genus of the hemipteran family Belostomatidae, known colloquially as giant water bugs, toe biters and electric light bugs, distributed in tropical, subtropical and temperate areas of the world.[1][2] The greatest diversity of species occurs in the Americas, with only a single species in Europe, two in Africa, two in Australia and three in Asia.[2] It includes the largest true bugs with species capable of reaching a length of over 12 centimetres (4.7 in).[3] The South American L. grandis and L. maximus are the only species to commonly exceed 9 cm (3.5 in), with more typical lengths for the remaining species being between 4.5 and 9 cm (1.8 and 3.5 in).[2] Lethocerus sp. are distinguished from other genera in the Lethocerinae (Benacus and Kirkaldyia) by two symmetrical furrows in the inner pad of setae on the fore femur, the external borders of parasternites II and III narrowed and nearly straight, and with the setae of the tarsomeres following the line of the tibial setae.
Habits
Lethocerus sp. with wings open

Unlike giant water bugs in the subfamily Belostomatinae, females do not lay the eggs on the backs of males.[4] Instead, after copulation (often multiple sessions[5]) the eggs are laid on emergent vegetation (rarely on man-made structures) high enough above the waterline that the eggs will not be permanently submerged. The male then guards the eggs from predators and periodically brings water to the eggs to prevent their desiccation.[6]

Like other members of the giant water bug family, Lethocerus species are predators that overpower prey by stabbing it with the rostrum and injecting a saliva that includes a number of enzymes that break down proteins.[7] As many as 132 components have been found in their saliva or venom, several being similar to those found in assassin bugs.[8] The proboscis is then used to suck the liquified and semi-digested body fluid of the prey. The rostrum can also be used in self-defense, and the bite is very painful to humans, causing swelling and pulsating pain, but usually resolves within about five hours at most.[9]

Lethocerus adults are attracted to lights (hence the name electric light bug) and are attracted in large numbers as they disperse from one water body to another during the rainy season. Some species are eaten, particularly in Southeast Asia and a few are endangered.[10]
Species
There are two African species, L. oculatus of Madagascar (shown) and L. cordofanus of the mainland[2]
L. deyrollei is now generally placed in its own genus, Kirkaldyia[2]

As of 2006, this is an exhaustive listing of all known species of Lethocerus:[2]

Lethocerus americanus
Lethocerus angustipes
Lethocerus annulipes
Lethocerus bruchi
Lethocerus camposi
Lethocerus collosicus
Lethocerus cordofanus
Lethocerus delpontei
Lethocerus dilatus
Lethocerus distinctifemur
Lethocerus grandis
Lethocerus indicus
Lethocerus insulanus
Lethocerus jimenezasuai
Lethocerus maximus
Lethocerus mazzai
Lethocerus medius
Lethocerus melloleitaoi
Lethocerus oculatus
Lethocerus patruelis
Lethocerus truxali
Lethocerus uhleri

The oldest known fossil of the genus is an indeterminate species from the Bembridge Marls, Isle of Wight, UK.[11]

In addition to these, Lethocerus deyrollei, which is one of the best known giant water bugs, has traditionally been included in this genus, but in 2006 it was moved to Kirkaldyia.[2]
Wikimedia Commons has media related to Lethocerus.
References

D. R. Lauck & A. Menke (1961). "The higher classification of the Belostomatidae (Hemiptera)". Annals of the Entomological Society of America. 54: 644–657.
P. J. Perez-Goodwyn (2006). "Taxonomic revision of the subfamily Lethocerinae Lauck & Menke (Heteroptera: Belostomatidae)". Stuttgarter Beiträge zur Naturkunde. A (Biologie). 695: 1–71.
Haddad Jr; Schwartz; Schwartz; and Carvalho (2010). Bites Caused by Giant Water Bugs Belonging to Belostomatidae Family (Hemiptera, Heteroptera) in Humans: A Report of Seven Cases. Wilderness & Environmental Medicine 21: 130–133.
Ichikawa, Noritaka (1988). "Male brooding behaviour of the giant water bugLethocerus deyrollei vuillefroy (Hemiptera: Belostomatidae)". Journal of Ethology. 6 (2): 121–127. doi:10.1007/BF02350877. ISSN 0289-0771.
Ichikawa, Noritaka (1989). "Repeated copulations benefit of the female in Lethocerus deyrollei vuillefroy (Heteroptera: Belostomatidae)". Journal of Ethology. 7 (2): 113–117. doi:10.1007/BF02350032. ISSN 0289-0771.
Smith, Robert L.; Larsen, Eric (1993). "Egg attendance and brooding by males of the giant water bugLethocerus medius (Guerin) in the field (Heteroptera: Belostomatidae)". Journal of Insect Behavior. 6 (1): 93–106. doi:10.1007/BF01049150. ISSN 0892-7553.
Rees, A. R.; Offord, R. E. (1969). "Studies on the Protease and Other Enzymes from the Venom of Lethocerus cordofanus". Nature. 221 (5181): 675–677. doi:10.1038/221675a0. ISSN 0028-0836.
Walker, Andrew A.; Hernández-Vargas, Maria José; Corzo, Gerardo; Fry, Bryan G.; King, Glenn F. (2018). "Giant fish-killing water bug reveals ancient and dynamic venom evolution in Heteroptera". Cellular and Molecular Life Sciences. 75 (17): 3215–3229. doi:10.1007/s00018-018-2768-1. ISSN 1420-682X.
Haddad, Vidal; Schwartz, Elisabeth F.; Schwartz, Carlos Alberto; Carvalho, Lucélia Nobre (2010). "Bites Caused by Giant Water Bugs Belonging to Belostomatidae Family (Hemiptera, Heteroptera) in Humans: A Report of Seven Cases". Wilderness & Environmental Medicine. 21 (2): 130–133. doi:10.1016/j.wem.2010.01.002.
Yoon, Tae Joong; Kim, Dong Gun; Kim, Seon Yi; Jo, Shin Il; Bae, Yeon Jae (2010). "Light-attraction flight of the giant water bug, Lethocerus deyrolli (Hemiptera: Belostomatidae), an endangered wetland insect in East Asia". Aquatic Insects. 32 (3): 195–203. doi:10.1080/01650424.2010.508045. ISSN 0165-0424.
Szwedo, Jacek; Drohojowska, Jowita; Popov, Yuri A.; Simon, Ewa; Wegierek, Piotr (September 2019). "Aphids, true hoppers, jumping plant-lice, scale insects, true bugs and whiteflies (Insecta: Hemiptera) from the Insect Limestone (latest Eocene) of the Isle of Wight, UK". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 110 (3–4): 331–396. doi:10.1017/S175569101900001X. ISSN 1755-6910.