''Belostoma flumineum'' is a North American species 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 ...

(family Belostomatidae). They are a common predator in ponds and wetlands. They are relatively large, reaching in length. As with other species of the

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, alligator ticks, or alligator fleas (in Florida). They are the largest insects in the or ...

family, the fathers take care of the offspring.Gilg, M.R., Kruse, K.C. (2003). Reproduction Decreases Life Span in the Giant Waterbug (''Belostoma flumineum''). The American Midland Naturalist, 149, 306–319. Exclusive

paternal care In biology, paternal care is parental investment provided by a male to his own offspring. It is a complex social behaviour in vertebrates associated with animal mating systems, life history traits, and ecology. Paternal care may be provided in co ...

has been the focus of many studies done on this species. Other studies have been done on

food webs A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Another name for food web is consumer-resource system. Ecologists can broadly lump all life forms into one ...

and predation pressure using this species because they are an

apex predator An apex predator, also known as a top predator, is a predator at the top of a food chain, without natural predators of its own. Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the highest trophic lev ...

(among invertebrates) in their preferred habitats.

Morphology

Ovoid-elongate in body shape that is dorsoventrally flattened and brown in coloration. They can range in length.Arnett, R. H. (2000). American Insects: A Handbook of the Insects of America North of Mexico. CRC press, 2, 284. ''B.flumineum'' are insects so naturally have six legs although the front two are strong

raptorial The term ''raptorial'' implies much the same as ''predatory'' but most often refers to modifications of an arthropod's foreleg that make it function for the grasping of prey while it is consumed, where the gripping surfaces are formed from the o ...

legs for catching and holding prey in a vice grip.O’Toole, C. (2009). Belostomatinae. In The New Encyclopedia of Insects and their Allies. Oxford University Press Print, 3,??-??. The other four legs are slightly flattened and used for swimming. The mouth parts consist of a stout syringe-like rostrum or beak and long piercing stylets that were once

mandibles In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...

and

maxillae The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

. They also have retractable strap-like appendages that allow for snorkeling while under water which are located on the posterier end of the

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...

. They have large eyes, but lack oceli, which are small light-detecting sensory organs.

Habitat and ecology

''Belostoma flumineum'' are commonly found in wetlands, marshes and ponds throughout North America. They live among weeds and like ponds with muddy bottoms which are good for over wintering in. Common species that ''B. flumineum'' prey upon are

backswimmer Notonectidae is a cosmopolitan family of aquatic insects in the order Hemiptera, commonly called backswimmers because they swim "upside down" (inverted). They are all predators and typically range from in length. They are similar in appearance t ...

s, water boatmen,

dragonfly A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of true dragonfly are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threate ...

nymphs, and

snail A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gastro ...

s.Severin, H. P., & Severin, H. C. (1911). Habits of ''Belostoma'' (=Zaitha) ''flumineum'' Say and ''Nepa apiculata'' Uhler, with Observations on Other Closely Related Aquatic Hemiptera. Journal of the New York Entomological Society, (2), 99. While they do not regularly participate in

cannibalism 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, b ...

they will attack smaller individuals of the same species. Reproduction in this species has 2 phases, a fall cycle and a spring cycle, where in the fall they are young breeders and in spring they are over wintered adults.

Paternal care

''Belostoma flumineum'' females lay their eggs on the backs of their mates and from this point onward it is the males' job to care for them until they hatch in 7–14 days. Males can carry up to 100 eggs on their backs at once.Crowl, T.A., Alexander Jr, J.E. (1988). Parental care and foraging ability in male water bugs (''Belostoma flumineum''). Canadian Journal of Zoology, 67, 513–515. Males care for their eggs by making sure the eggs get enough oxygen and protection from predators. Since the eggs are so large, they cannot stay submerged underwater and use

diffusion Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical p ...

to absorb oxygen available in the water.Tallamy, D.W. (2001). Evolution of Exclusive Paternal Care in Arthropods. Annu. Rev. Entomol., 46,139–65. The males must remain at the air-water interface so that the eggs are provided with enough oxygen, this behavior is called air brooding. Brood pumping and brood stroking are another behavior males do to increase the water flow over the eggs for better oxygen access. Even though males care for the eggs, they will still discard them depending on the egg pad size, age of the male, and the presence of females.Kight, S.L., Tanner, A.W., Coffey, G.L. (2011). Termination of Parental Care in Male Giant Waterbugs, ''Belostoma flumineum'' Say (Heteroptera: Belostomatidae) is Associated with Breeding Season, Egg Pad Size, and Presence of Females. Invertebrate Reproduction & Development, 55, 197–204. It has also been found that males with small egg pads have a temperature-dependent discard rate because cooler temperatures mark the end of breeding season; at cool temperatures, they are less likely to discard a small egg pad compared to warmer temperatures.Kight, S.L, Batino, M., Zhang, Z. (2000). Temperature-Dependent Parental Investment in the Giant Waterbug ''Belostoma flumineum'' (Heteroptera: Belostomatidae). Annals of the Entomological Society of America, 93, 340–342.

Research

There have been a number of studies done using this species of water bug.

Food web A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Another name for food web is consumer-resource system. Ecologists can broadly lump all life forms into one ...

and habitat studies have used ''B. flumineum'' as the predation pressure for tadpoles and observed the difference between vegetated areas and non vegetated areas when looking at the survival rate of tadpoles. They found that the tadpoles survived better in highly vegetated area even though those areas tended to have more predators in them.Tarr, T.L., Babbit, K.J. (2002). Effects of habitat complexity and predator identity on predation of Rana clamitans larvae. Amphibia-Reptilia, 23,13–20. Other studies used ''B. flumineum'' as a predation pressure on snails to see if they would change their susceptibility though

ontogeny Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the stu ...

,Chase, J.M. (1999). To Grow or to Reproduce? The Role of Life-History Plasticity in Food Web Dynamics. The American Naturalist. 154, 571–586. and as a stress inducer on amphibians to see if that would make them more susceptible to disease.Haislip, N.A., Hoverman, J.T., Miller, D.L., and Gray, M.J. (2012). Natural Stressors and Disease Risk: Does the Threat of Predation Increase Amphibian Susceptibility to Ranavirus?. Canadian Journal of Zoology, 90, 893–902. The other main area of research done using this species was on factors that influence paternal care. Crowl and Alexander studied the potential costs of males brooding, specifically if brooding affected their ability to forage for food. They did get results that suggested that brooding males could not catch faster prey, such as small fish, as well as females or non-brooding males could and thus it does have a foraging effect. Gilg and Kruse wanted to test if reproduction decreased life span and they chose ''B. flumineum'' because both the female and male have relatively high costs of reproduction. The females require a lot of energy to make such large eggs and then the males spend energy brooding eggs and are more exposed to predators. They did find statistically significant differences between the life spans of virgin and breeding in both males and females.

References

{{Taxonbar, from=Q10427979 Belostomatidae Hemiptera of North America Insects described in 1832 Taxa named by Thomas Say