Observations on the life
history of giant water bugs Lethocerus Mayr, 1853 (Heteroptera:
Nepomorpha: Belostomatidae) in the Gangetic plains of India and Nepal
Hasko Nesemann 1& Gopal Sharma 2
1 Ashokraj Path, Sonapalace,
Mahendru, Patna, Bihar 800006, India
2 Zoological Surveyof India, Gangetic Plains Regional Centre, Rajendra Nagar, Patna, Bihar 800016,
India
1 hnesemann2000@yahoo.co.in (corresponding author), 2 gprszsipatna@rediffmail.com
doi: http://dx.doi.org/10.11609/JoTT.o3497.4474-82 | ZooBank: urn:lsid:zoobank.org:pub:4E39AE2A-1F27-4B89-8477-081020FEA48A
Editor: Ragnar Kinzelbach, University of Rostock, Rostock, Germany. Date
of publication: 26 June 2013 (online & print)
Manuscript details: Ms # o3497 | Received 29
January 2013 | Final received 31 March 2013 | Finally accepted 03 June 2013
Citation: Hasko Nesemann & Gopal Sharma (2013). Observations on the life history of giant water bugs Lethocerus Mayr, 1853 (Heteroptera: Nepomorpha: Belostomatidae) in the Gangetic plains
of India and Nepal. Journal of Threatened Taxa 5(10): 4474–4482; http://dx.doi.org/10.11609/JoTT.o3497.4474-82
Copyright: © Nesemann & Sharma 2013. Creative Commons Attribution 3.0 Unported License. JoTT
allows unrestricted use of this article in any medium, reproduction and
distribution by providing adequate credit to the authors and the source of
publication.
Funding: First author: Scholar-In-Residence under the
UGC scheme at Central University of Bihar funded through the University Grants
Commission, New Delhi.
Second author: Annual research program for
aquatic faunal study of rivers of Jharkhand under Ministry of Environment and
Forests.
Competing Interest: None.
Acknowledgements: We thank the University
Grants Commission (New Delhi, India), Central University of Bihar (Patna, India) , Dr. K. Venkataraman, Director, Zoological Survey of India,
Kolkata, R.K. Sinha (Department of Zoology, P.U., Patna, India), Ram Kumar
(Centre for Environmental Science, CUB, Patna, India), Deep Narayan Shah and
Ram Devi Tachamo Shah (Department of Limnology and Nature Conservation,
Senckenberg Research Institutes and Natural History Museums, Gelnhausen,
Germany) for their kind help in fieldwork; Herbert Zettel (Entomological
Department, Natural History Museum Vienna, Austria) for valuable support,
encouragements and discussion.
Author Contribution: HN and GS conducted fieldworks and equally
contributed in manuscript preparation. HN illustrated the specimens.
Author Details: Hasko Nesemann is expert in aquatic biology
and Gopal Sharma is aquatic
biologist and freshwater dolphin expert. They are specialized in aquatic
biodiversity with a keen interest in freshwater ecology, biogeography,
conservation, and ecological water quality monitoring.
Abstract: Two species of giant water bugs Lethocerus were found
in the Gangetic plains of northern India and Nepal. Lethocerus indicus iswidespread, whereas a single record of Lethocerus patruelis confirms the
eastern distribution range in Bihar. Four instars of aquatic nymphs occur exclusively in temporary shallow
stagnant water bodies which harbor rich amphibian
populations but lack permanent fish fauna. From mid-August to the first week of November adults fly. Later they live submerged in aquatic
habitats of large rivers and permanent stagnant water bodies
which harbor diverse fish fauna. Repeated findings of adults with ventrally attached egg-shaped pupae of
aquatic mites (Hydracarina) suggest that these are host-specific ones of Lethocerus. Thus, the occurrence of protelean
parasites on giant water bugs in the Gangetic plains is a previously unknown
unique finding since apparently mites have been noticed only from other
Nepomorpha families.
Keywords: Aquatic insect, gangetic plains, giant water
bug, hydracarina, host-specificity, India, life cycle, Nepal, protelean mites.
For figures, images, tables -- click here
Introduction
Aquatic bugs of the
infraorder Nepomorpha are hemimetabolous insects. The juvenile stages (nymphs) are similar
to the adult forms but they are distinguished by the successive growth of their
wing pads. The nymphs are fully
aquatic whereas many of the winged mature Nepomorpha can fly. This is an important strategy in the
life cycle for active dispersal and colonization of new habitats. The largest arthropods in freshwaters
are mostly represented by decapods Crustaceans like crabs, prawns and crayfish
but several aquatic bugs are noticeably robust insects of an unusually large
size with raptorial forelegs. Belostomatidae are named giant water bugs with about 160 accepted
species worldwide of three subfamilies (Polhemus & Polhemus 2008; Morse
2009; Henry 2009). Some members of
the subfamily Lethocerinae reach 109–115 mm total body length, the
maximum size of adult aquatic insects (Perez-Goodwyn 2006). Their distribution range includes the
circum- tropical, subtropical and warm-temperate zones of all continents. The family Belostomatidae also shares
several characters with the definition of “living fossils” since similar
representations of these bugs are already known as fossil documentations from
the Upper Triassic of Virginia (North America) since 210 Million years ago
(Andersen & Weir 2004). The oldest
Lethocerinae are found in the Jurassic of Germany with Mesobelostomum
depertitum (Germar, 1839) (Ponomarenko 1985; Popov 1992). At present three extant genera BenacusStål, 1861 (monotypic), Kirkaldyia Montandon, 1909 (monotypic), and LethocerusMayr, 1853 (22 species) are recognized with 24 species. The highest diversity with 17 species is
observed in the neotropical region (Perez-Goodwyn
2006; Choate 2011). Records of
tropical Asian Lethocerinae species are scattered in the literature (Easton
& Wing-Wah Pun 1997; Sharma 1998; Bal & Basu 2002; Nahar 2004; Chen et
al. 2005; Lekprayoon et al. 2007; Nesemann et al. 2012), only Thirumalai (2007)
has summarized the distribution for India. Giant water bugs of the genus Lethocerus are traditionally used
as human food in South-East Asia.
Lethocerinae appear to be a
well-studied group of large-sized insects which is
reflected in a comparatively high number of articles and book chapters dealing
with their biology (Dudgeon 1999; Deckert & Göllner-Scheiding 2003; Polhemus
& Polhemus 2008; Morse 2009; Henry 2009). Perez-Goodwyn (2006: 7) stated: “The
reproductive behavior is peculiar in the family and different to that of
Belostomatinae. The female lays her
eggs outside the water (“emergent brooders” according to Smith 1997) on a
vegetal substratum (sticks, so far as known, but L. mazzai chooses moss
at the border of the ponds as substratum, see De Carlo, J.M. 1962). The male guards the eggs until hatching,
keeping them moist and defending them from predators.” Biological observations
of four American and two Oriental species are published, namely Lethocerus
americanus (Leidy, 1847) (Hoffman 1924; Hungerford 1925), Lethocerus
maximus De Carlo, 1938 (Cullen 1969), Lethocerus mazzai De Carlo,
1961 (De Carlo 1969), Lethocerus medius (Guérin-Méneville, 1857) (Smith
& Larsen 1993) and Lethocerus indicus (Lepeletier & Serville
1825) (Hoffman 1933a,b). The
behavior of Kirkaldyia deyrolli (Vuillefroy 1864) is the best known, and
is one of the reference points for the post-embryonic paternal care in insects
(Ohba 2011). The life-cycleof these five species was supposed to be, in general, valid for other
Lethocerinae including the old world members (Dudgeon 1999). Eggs of Lethocerus delpontei De
Carlo, 1930 and Kirkaldyia deyrolli were described by Perez-Goodwyn et
al. (2006: 155) and the authors assumed: “Due to the increase in size of the
adults in order to have access to a vertebrate diet, the eggs should also
increase in size.” Aquatic mites
(Arachnida: Acari: Hydracarina) were only accidentally noticed in association
with Lethocerus spp. (Marlos 2010a) but regularly reported from other
Nepomorpha (Proctor 1998; Hawking et al. 2009; Marlos 2010b).
Material
and Methods
During field studies of
benthic macro-invertebrate fauna the aquatic bugs were collected with the help
of a 1mm mesh sized net by hand from the shallow zones of running and stagnant
waters. Rivers and wetlands of the
Gangetic plains were studied in Bihar, Jharkhand, West Bengal, New Delhi and
Nepal and a total of 17 localities for Lethocerus species were
discovered from 2004–2012 (Fig. 1). A few flying adults were also collected near light sources. All other records are nymphs and adults
from aquatic habitats. The material
was preserved together with all available benthic macro-invertebrates in a
mixture of ethanol and formaldehyde for hardening the insects. After washing and sorting the specimens
were kept in separate jars, labeled and transferred into 70% ethanol. The maximum body length and the width of
all specimens was measured using a slide caliper. In adult specimens the distinction of
males and females was based on the genital plate whichwas studied with a Leica stereo-zoom microscope. Attached pupae were studied by a high
magnification Olympus microscope. Identification of adults was done with the keys provided by Menke (1960)
and Perez-Goodwyn (2006). The
voucher material is deposited in the collection of the Zoological Survey of
India, Gangetic Plains Regional Centre in Patna. All specimens deposited with their
location and registration numbers are listed in the results.
Results
Two species of giant water
bugs could be identified. Lethocerusspp. was found in eight lowland rivers and eight stagnant water bodies of the
floodplains. The aquatic habitats
of adults were predominantly large rivers but also one oxbow lake and one pond,
whereas the exclusively aquatic nymphs (or larvae) were found only in temporary
shallow ditches of riverine floodplains. These reproduction habitats are all characterized by seasonal water
during the monsoon period starting from the month of June/July onwards. They dry completely after the following
winter and are not inhabited by any fish fauna. The aquatic vertebrate fauna herein
consist of tadpoles and adult amphibians which were
abundantly found during the inundation period.
Lethocerus indicus (Lepeletier & Serville,
1825)
New Delhi:
River Yamuna at
Jangshola near Palla: 28051’24”N
& 77012’27”E, elevation 210m, 01.iv.2004, 1 adult collected in
dense Hydrilla verticillata plants, released, coll. Rajiv Kumar & H.
Nesemann.
Nepal:
Rautahat
District: Barahwa Nadi (Ox-bow Lake) East of Gaur, 26046’13”N &
85016’53”E, elevation 77m, 06.v.2006, 1 adult male with ventrally
attached pupae, collected in dense Ceratophyllum demersum plants, coll.
H. Nesemann & ASSESS-HKH party (ZSI/GPRC/IV-3035).
West Bengal:
River
Subernarekha at Gopiballabhpur upstream road bridge: 22013’15”N
& 86054’01”E, 20.xi.2008, 1 adult the specimen was collected
from the small pool below the river bridge pillar, elevation 36m, coll. G.
Sharma & GPRC party (ZSI/GPRC/IV-3023).
Jharkhand:
River Damodar
at Fushro bridge, Chandrapura: 23045’40”N & 86000’50”E, elevation 205m,
28.ix.2010, 1 adult female with few ventrally and dorsally attached pupae,
collected from the slow water current attached with aquatic macrophytes, coll.
G. Sharma & GPRC party (ZSI/GPRC/IV-3021).
Bihar:
Patna: BIT Campus near
Airport: flying adults, collected in evening near light of sports ground, 25055’45”N & 85005’16”E, elevation 55.4m,
08–10.x.2010, 1 female, 3 males, inside BIT Canteen “Mother’s Food”,
15.viii.2011, 1 female, coll. H. Nesemann (ZSI/GPRC/IV-3022).
River Ganga at Patna,
upstream Darbhanga House: 25037’19”N & 85009’46”E,
elevation 50.6m, 28.ii.2012, 1 adult male collected under large stones in
shallow water, coll. H. Nesemann (ZSI/GPRC/IV-3034).
River Gandak at Ramnagar
upstream Hajipur: 25048’07”N
& 85010’33”E, elevation 53m, 23.v.2012, 1 adult
female collected from unvegetated open water of the river bank at the water’s
edge, coll. G. Sharma & H. Nesemann (ZSI/GPRC/IV-3024).
River Punpun upstream
Fatehpur (south of Patna): 25030’12”N & 85011’37”E,
elevation 52m, 12.v.2012, 1 adult male collected from unvegetated open water of
the river bank at the water’s edge, coll. H. Nesemann (ZSI/GPRC/IV-3025).
River Punpun at
Masauri-Railway bridge upstream road bridge (south of Patna): 25030’06”N
& 85006’06”E, elevation 54m, 19.v.2012, 1 adult male
with ventrally attached pupae, collected under large stones near Vallisneria
spirallis plants in the middle of the river bed, coll. G. Sharma & H.
Nesemann (ZSI/GPRC/IV-3026).
River Ghaghara at Manjhi
bridge: 25049’19”N & 84035’12”E, elevation 56m,
16.vi.2012, 1 adult male with ventrally attached pupae, collected in dense Potamogeton
pectinatus plants from an isolated pool (>1.5m water depth) next to the
main channel’s left bank, coll. G. Sharma & H. Nesemann (ZSI/GPRC/IV-3027).
Nalanda District: Small fish-pond in village Korawan (near Hilsa): 25018’51”N
& 85011’23”E, elevation 59.3m, 02.xi.2011, 1 adult
female collected from the bottom, coll. G. Sharma & H. Nesemann (ZSI/GPRC/IV-3028).
Hajipur, Small pond withPila globosa west of Mamu Bhanja Pokhra: 25040’35”N & 85013’26”E,
elevation 52.4m, 16.vii.2011, 1 nymph collected from shallow water in submerged
grasses, coll. H. Nesemann. Additional nymphs were observed (ZSI/GPRC/IV-3029).
Hajipur, Shallow ditch north-west of Mamu Bhanja Pokhra: 25040’30”N
& 85013’32”E, elevation 52.4m, 16.vii.2011, 1 nymph,
coll. H. Nesemann. 24.vii.2011, 3 nymphs, 03.viii.2011, coll. G. Sharma &
H. Nesemann, 1 nymph, 26th August 2012, 1 nymph, collected from
shallow water in submerged grasses, coll. H. Nesemann. Additional nymphs were
observed (ZSI/GPRC/IV-3030, ZSI/GPRC/IV-3036).
Gandak floodplain, embankment
upstream Hajipur, Ramnagar Kund, medium-sized (temporary monsoon) pond in Mangifera
indica orchards: 25048’11”N & 85010’46”E, elevation 57.3m,
14.viii.2011, 2 nymphs, 29.vii.2012, 5 nymphs, collected from shallow water in
submerged grasses, coll. G. Sharma & H. Nesemann. Additional nymphs were
observed (ZSI/GPRC/IV-3032).
Gandak floodplain, embankment
near Vaishali, shallow floodplain ditch (open meadow) near of Bherampur: 25055’03”N
& 85006’58”E, elevation 57.9m, 07.viii.2011, 2 nymphs
collected from shallow water in submerged grasses, coll. G. Sharma & H.
Nesemann (ZSI/GPRC/IV-3033).
Valmiki Tiger Reserve and
Sanctuary: Gandak floodplain: Temporary shallow ditch near Rohua Nala, Madanpur
Forest Range, surrounding dense mixed bushy forest and reed: 27011’38”N
& 83059’41.84”E, elevation
97m, 09.vii.2012, 1 nymph collected from shallow water in submerged grasses,
coll. G. Sharma & H. Nesemann (ZSI/GPRC/IV-3037).
Lethocerus patruelis (Stål, 1854)
River Budhi Gandak at
Seuri-Bridge North of Begusarai: 25032’24”N & 86007’50”E,
elevation 42m, 26.v.2012, 1 adult male with 45 ventrally attached pupae,
collected in dense Vallisneria spiralis plants, coll. H. Nesemann &
Ram Kumar (ZSI/GPRC/IV-3038).
Biological observations
A total of 35 specimens of Lethocerus
indicus were included in the present analysis (Image 1), these are in
particular 22 nymphs, eight male and five female adults (Table 1). The nymphs
can be grouped into four different instars according to their body size; the
length is given here in mm. The
first available development stage (1st instar on Image 1) ranges from
8.5–9.3 mm and is represented by six individuals but approximately one
dozen of the same sized nymphs were additionally observed in localities no. 12
and 13 at Hajipur. The next
following instars reaching 13–19.5 mm (2nd instar on Image 1,
two nymphs), 30–33.1 mm (3rd instar on Image 1, seven nymphs)
and 47–52 mm (4th instar in Image 2, seven nymphs)
respectively. The presence of
aquatic nymphs was observed only in the months of July and August.
The adults were identified
males or females based on the different shape of the genital plates (Images
3,4). The male individuals reach 64–73 mm whereas the females are
generally larger with 73–76.3 mm body length. Submerged diving adults
were observed in large and deep water bodies in the
months of February, May, June, September and November. A single flying terrestrial adult was
found in the month of August whereas they could be frequently seen in large
numbers during the month of October, the monsoon not ending until the first
week of November.
Three adult males and one
female individual of the preserved material bear upto 7–47 ventrally
attached pupae on the underside of the thorax and between the second and third
pairs of legs. These are ‘protelean parasites’ with inactive pupa-like stages
(Proctor 1998; Hawking et al. 2009) that represent the ‘protonymph’ and
‘tritonymph’ of aquatic mites (Acari: Cohort Parasitengona: Hydracarina) having
striking similarity with eggs of Nepomorpha (Andersen & Weir 2004). The pupae of 1.0mm total length (Images
5,6) contain aquatic mites with four visible eye spotsand readily developed legs. They
have a yellowish-ochre color with white apices. The pupae-bearing male giant water bugs
were found in the months May and June. A single female individual with only a few attached pupae from Damodar
River was collected during floods in the month of September. Repeated observations of adults with
ventrally attached pupae suggest that these are host-specific mites of Lethocerusspp. and they are not deposited accidentally using giant water bugs as
substrate.
The single adult male
specimen measured 55.2mm body length and 21.2mm maximum body width. It is well distinguished by its small
size and from the Larger Indian Giant Water Bug L. indicus. The remarkable finding confirms the sympatric
occurrence of two species as it was already noticed for New Delhi where both L. indicus and L. patruelis were
identified by Perez Goodwyn (2006). Furthermore, the presence of L. patruelis in
Sikkim was mentioned by Thirumalai (2007).
The adult male individual
bears around 45 ventrally attached pupae of aquatic mites (Hydracarina) on the
underside of the thorax between the second and third pairs of legs. The pupae of 1.0mm total length contain
mites with four visible eye spots and readily
developed legs (Image 7). They have
a light yellow color with white apices. Thus the behavior of the mite’s pupal stages resembles the observations which were made for Lethocerus indicusin the lower Gangetic plain.
The habitat is a
pollution-free and clear lowland river that originates from the Gangetic plain
of northern Bihar. The Budhi Gandak
is characterized by a very dense benthic molluscan fauna (five Bivalvia
species, 11 Gastropoda species), the dragon fly nymph Macromia cf. mooreiSelys, 1874 and accompanying adult bugs Laccotrephes griseus(Guerin-Meneville, 1844), Laccotrephes ruber (Linnaeus, 1764), Ranatra
elongata Fabricius, 1790, Ranatra filiformis Fabricius, 1790. The total number of macro-invertebrate
taxa reaches 25 species at the spot where the adult Lethocerus patruelishas been discovered. Thus water
condition and biological community indicate high habitat quality in comparison
with Lethocerus indicus habitats which have
slightly turbid water and visibly higher eutrophication.
Discussion
Prey
The subfamily Lethocerinae is
known to be a vertebrate specialist that preys upon fish, amphibians, snakes
and juvenile turtles. Lethocerus
americanus (Leidy, 1847) is reported to prey also on aquatic Insecta,
Cladocera and Gastropoda (Ohba 2011).
Nymphs
The
species identity of nymphs is simply concluded from the adults found in the
neighboring localities. It has to
be mentioned that neither have their distinguishing characters been
sufficiently studied nor have the wingless juvenile development stages of Lethocerusspecies been considered in the identification keys (Merritt & Cummins 1996;
Goodwyn 2006; Huber et al. 2006). In the present study four instars of Lethocerus indicus were
found in the field, also five moltings have been reported for North American
species. The smallest nymphs of Lethocerusindicus which were found in
the Gandak floodplain from the second half of July onwards alreadyhad a body length of 8.5–9 mm.
Habitat selection
It is noteworthy that the
aquatic habitats of the adult Giant Water Bugs of the genus Lethocerus differ
from the habitats of their nymphs which suggest a
partly divided strategy in their life cycle. The instars of aquatic nymphs do not
live in competition or under predatory pressure of fishes since they were found
only in temporary water bodies. Thus the strategy to use such habitats for breeding shows the biological
importance to protect the nymphs and to provide an easily capable food resource
in the form of invertebrates and amphibians such as various sized
tadpoles. In contrast, the adult
winged stages inhabit permanent water bodies whichharbor rich fish diversity.
Protelean ‘Parasites’
These Hydracarina have a
complex life-cycle, consisting of a parasitic larva,
two inactive pupa-like stages that represent the protonymph and tritonymph, and
active predatory deutonymphal and adult stages (Proctor 1998). The attached Hydracarina larvae are
parasitic while deutonymphs and adults are predatory. Pupation takes place on the parasitized
invertebrate. Our observations show
that only adults of Lethocerus species in
rivers are colonized by aquatic parasitengone mites. Out of these mostly the second stage
(tritonymphs) have been found in the months of May and June (localities no. 2,
10, 11) whereas a few smaller protonymphs were available in the month of
September (locality no. 4). Both species Lethocerus indicus and Lethocerus
patruelis bear remarkable similar tritonymphs whichmay represent the same species of Hydracarina. Although adult mites were not found in
the present survey, the nymphs display unique characters that differ from
previous observations (Marlos 2010a) as well as other Hydracarina of the study area.
Life cycle of Lethocerusspecies in the Gangetic plains
The first instars of aquatic
nymphs appear in July and August in shallow temporary water bodies. They grow fast within two months and
they molt several times, of which four instars of aquatic nymphs plus the winged
adults have been observed. Adult
dispersal by flying was seen frequently during the month of October till the
first week of November. From winter
to the month of June the adult Lethocerus species display an aquatic
life style inside large water bodies like rivers, oxbow lakes and
fishponds. During the aquatic
period adult Lethocerus is host to parasitengone aquatic mites
(Hydracarina) which spend a part of their life-cycle
as parasitic “pupae” (protonymph, tritonymph) attached on adult bugs. Usually they are found in one to three
groups attached on the ventral side of males. Tritonymphs of the second development
stage of mites are carried from the first week of May to mid-June, smaller
protonymphs in September.
References
Bal, A. & R.C. Basu
(2002): Insecta:
Hemiptera: Water-Bugs, pp. 77–87. In:
Ramakrishna (ed.): Fauna of Kawar Lake Wetland (Bihar). Wetland Ecosystem Series 4. Zoological Survey of
India, Kolkata, 134pp,
Chen, P.P., N. Nieser & H. Zettel (2005).The Aquatic and Semi-Aquatic Bugs of Malesia. Fauna of
Malesia, Press, HKU, 291–316pp.
Choate, P.M. (2011). Giant Water
Bugs, Electric Light Bugs, Lethocerus, Abedus, Belostoma (Insecta:
Hemiptera: Belostomatidae). EENY-301 (IN578), pp. 1–6,
University of Florida. <http://www.entomology.ifas.ufl.edu/creatures. http://www.edis.ifas.ufl.edu>. Downloaded on 13 January2013.
Cullen, M.J. (1969). The
biology of giant water bugs (Hemiptera: Belostomatidae) in Trinidad. Proceedings of the royal entomological Society London (A)44: 123–127.
Deckert, J. & U. Göllner-Scheiding (2003). 24.
Ordnung Heteroptera, Wanzen, pp. 402–423. In: Dathe, H.H. (ed.): Lehrbuch
der Speziellen Zoologie. Band 1: Wirbellose Tiere. 5. Teil: Insecta.
Dudgeon,
D. (1999). Tropical Asian Streams: Zoobenthos, Ecology and Conservation. Hong Kong University Press, HKU, 291–316pp.
Easton,
E.R. & Wing-Wah Pun (1997). Observations on some Hemiptera/Heteroptera of
Macau, Southeast Asia. Proceedings of the Entomological Society Washington 99 (3):
574–582.
Hawking, J.H., L.M. Smith
& K. Le Busque (eds) (2009). Hydracarina (water mites). In: Identification
and Ecology of Australian Freshwater Invertebrates. <http://www.mdfrc.org.au/bugguide>,
Version January 2009. Downloaded on 11 February 2013.
Henry, T.J. (2009). Biodiversity of Heteroptera,
pp. 223–264. In: Foottit, R. & P.H. Adler (eds.): Insect
Biodiversity, Science and Society. Blackwell Publishing, xxi+632pp.
Hoffman, W.E. (1924). Biological
Notes on Lethocerus americanus (Leidy.). Psyche 31(5):
175–183; http://dx.doi.org/10.1155/1924/86146
Hoffman, W.E. (1933a). A
preliminary list of the aquatic and semiaquatic Hemiptera of China, Cosen
(Korea) and Indo-China. Lingnan Science Journal12: 243–258.
Hoffman, W.E. (1933b). Additional
data on the life history of Lethocerus indicus (Hemiptera:
Belostomatidae). Lingnan Science Journal 12: 595–601+3pls.
Huber, T., W. Graf & A. Schmidt-Kloiber (2006). Key to Heteroptera (Bugs). Regional capacity building
workshop on Macro-invertebrate Communities to evaluate the ecological status of
rivers in the Hindu Kush Himalayan Region. August 20thto September 9th 2006, Kathmandu University, Dhulikhel, Nepal,
1–4pp.
Hungerford, H.B. (1925). Notes on
the giant water bugs (Lethocerus and Benacus -Belostomatidae
Hemiptera). Psyche32(2): 88–90+1pl; http://dx.doi.org/10.1155/1925/24273
Marlos, D. (2010a). Toe biter with mites? Image
submitted by Maria Juliano. <http://www.whatsthatbug.com/2007/05/10/toe-biter-with-mites/.> Assessed on 11.02.2013.
Marlos, D. (2010b). Aquatic
mites on water scorpion. Image submitted by Eric Snyder.
<http://www.whatsthatbug.com/2009/07/03/aquatic-mites-on-water-scorpion/.> Assessed on 11.02.2013.
Menke, A. (1960). A review
of the genus Lethocerus in the Eastern Hemisphere, with the description
of a new species from Australia. Australian Journal
of Zoology 8: 258–288.
Merritt, R.W. & K.W. Cummins (1996). An
Introduction to the Aquatic Insects of North America - Third Edition. Kendall/Hunt
Publishing Company, Iowa, xiii+862pp.
Morse, J.C. (2009). Biodiversity
of aquatic insects, pp. 165–184. In: Foottit, R. & P.H. Adler
(eds.). Insect Biodiversity, Science and Society. Blackwell Publishing, xxi+632pp.
Nahar, S.C. (2004). Aquatic
insects, pp. 195–213. In: State Fauna Series 11: Fauna of Bihar
(Including Jharkhand), Part-1: 195-213, Zoological Survey of India,
Kolkata.
Lekprayoon,
C., M. Fuangarworn & E. Mongkolchaichana (2007). The Water Bugs (Hemiptera:
Heteroptera) from the Western Thong Pha Phum Research
Project Area, Kanchanaburi Province, Thailand. Research Report of Project BRT
Western Thong Pha Phum (2550): 38–51. <www.biotec.or.th/.../200-the-water-bugs-hemiptera-heteroptera-from...>
Downloaded on 20 January 2013.
Nesemann, H., G. Sharma &
M. Sardana (2012). Aquatic macro-benthic Arthropoda diversity of temporary and
permanent wetlands in and around Patna with pictorial guide of aquatic bugs
(Heteroptera: Nepomorpha). Spectrum Journal
of Science and Society for Sustainable Development 2(1–4):
75–84.
Ohba, S.
(2011). Field observation of predation on a turtle by a giant water bug. Entomological Science 14(3): 364–365; http://dx.doi.org/10.1111/j.1479-8298.2011.00450.x
Perez-Goodwyn,
P.J. (2006). Taxonomic revision of the subfamily
Lethocerinae Lauck & Menke (Heteroptera: Belostomatidae). Stuttgarter Beiträge zur Naturkunde Serie A (Biologie) 695:
1–71.
Perez-Goodwyn,
P.J., S. Ohba, & J.A. Schnack (2006). Chorion
morphology of the eggs of Lethocerus delpontei, Kirkaldyia deyrolli,
and Horvathinia pelocoroides (Heteroptera: Belostomatidae). Russian Entomological Journal 15(2): 151–156.
Polhemus,
J. T. & D. A. Polhemus (2008). Global diversity of true bugs (Heteroptera;
Insecta) in freshwater. Hydrobiologia 595(1): 379–391;
http://dx.doi.org/10.1007/s10750-007-9033-1
Ponomarenko, A.G. (1985). Fossil insects from the
Tithonian, Solnhofener Plattenkalke” in the Museum of Natural History, Vienna. Annalen des Naturhistorischen Museums in Wien 87 A: 135-144.
Popov, Y.A. (1992). Jurassic bugs (Hemiptera:
Heteroptera) from the Museum of Natural History in Vienna. Die jurassischen
Wanzen (Hemiptera: Heteroptera) des Naturhistorischen Museums in Wien. Annalen des Naturhistorischen Museums in Wien 94 A: 7-14.
Proctor, H. (1998). Parasitengona. Velvet mites,
chiggers, water mites. Version 09 August 1998.
<http://tolweb.org/Parasitengona/2581/1998.08.09 in: The Tree of Life
Web Project, http://tolweb.org/ >, Downloaded on 11 February 2013.
Sharma,
S. (1998). An Inventory of Nepal’s Aquatic Insects used as Biological
Indicators of Water Pollution. Funded by University Grants Commission, New
Beneshwar, Kathmandu, Nepal, 117pp.
Smith, R.L. (1997). Evolution
of paternal care in giant water bugs (Heteroptera: Belostomatidae), pp.
116–149. In: Choe, J.C. & B.J. Crespi (eds.). The
Evolution of Social Behavior in Insects and Arachnids. Cambridge University Press.
Smith,
R.L. & E. Larsen (1993). Egg attendance and brooding by males of the Giant Water Bug Lethocerus
medius (Guerin) in the field (Heteroptera: Belostomatidae). Journal of Insect Behavior 6: 93–106.
Thirumalai, G. (2007). A Synoptic List of Nepomorha (Hemiptera:
Heteroptera) from India. Records of the Zoological
Survey of India, Occasional Paper No. 273: 1–84.