Triatoma sanguisuga

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Geographic Range

Triatoma sanguisuga is found in the southeastern United States and throughout Latin America. This range includes both the Nearctic and Neotropical regions. It occupies North America in a range stretching from Pennsylvania to Florida and as far west as Arizona. Most research on this insect is performed only with regard to the United States, so an exact range in Latin American is unknown. (Cesa, et al., 2011; Dorn, et al., 2007; Kobylinski and Connelly, 2009)

Habitat

Triatoma sanguisuga is found in terrestrial and wooded environments where small mammals live. Wood rats are the most common host for these blood sucking insects, and the rat nests provide a convenient home for the insects. Large flat rocks, detritus, and wood piles provide structural support for the rat nests and safety for the insects because they can feed, digest, and lay their eggs within. Triatoma sanguisuga also nests in human residences or farms when utilizing other animal sources of blood. It can be found under loose wooden floorboards and older building structures. (Encyclopedia Britannica, 2012; Grudemann, 1947)

Physical Description

Triatoma sanguisuga is on average 22 mm long and exhibits bilateral symmetry. It has an oval-shaped black body with red stripes on the outer edge of its thorax that continue onto its abdomen. Its two rear legs are twice as long as its four front legs. Its narrow head projects from its body, with large eyes protruding from half-way. T. sanguisuga has a significant proboscis on its head that is used to enter the blood vessel of its host during feeding. Jointed antennae also project from mid-way on the head. The sensory organs on the antennae, called sensilla, exhibit one example of sexual dimorphism in T. sanguisuga, where males have a higher density and different patterns than females. Nymphal instars are morphologically similar to adults, except they lack wings and their heads are slightly smaller. Eggs are small, white ovals measuring between 1 to 2 mm.

Different populations of the insect are influenced by different geographical barriers - and consequently, multiple haplotypes and physical characteristics have developed. (Catalá, 1997; Klotz, et al., 2009; Roden, et al., 2011; Stevens, et al., 2011; Wild, 2012)

  • Sexual Dimorphism
  • sexes colored or patterned differently
  • Range length
    12 to 36 mm
    0.47 to 1.42 in
  • Average length
    22 mm
    0.87 in

Development

These insects are hemimetabolous, and have incomplete metamorphosis. Life stages include the egg, nymph (instars), and adult. The eggs of Triatoma sanguisuga are deposited once the female has been fertilized and has received a blood meal. During embryonic development, a higher environmental temperature speeds development. A nymphal instar finds a blood meal 2 to 3 days after hatching. During the nymphal stage, T. sanguisuga undergoes ecdysis, which is repeated cycles of shedding. After sufficient feeding and digestion time, the molting hormone is released which signals the nymphal instar to molt. If born early in the warm season, a nymph can complete five instar stages, each separated by a molt. It undergoes hibernation during the winter months, during which it remains in an awakened sluggish state. The remaining nymphal stages are completed the following year if not completed in the first summer season. After completing 8 nymphal instar stages, the insect is considered to be an adult. (Grudemann, 1947; Stevens, et al., 2011)

Reproduction

Females and males are polygynandrous; each sex finds multiple mates during their lifespan. Shorter in comparison to related insects, the mating time of T. sanguisuga lasts only 10 minutes. After male fertilization, females migrate to a new territory to found a new community. (Stevens, et al., 2011)

A female develops eggs in her ovarioles, but does not deposit them until she has been fertilized and has received a blood meal. Depending on host preference, space availability, and season of sexual maturity, a female can lay hundreds of eggs during her life. More eggs are laid when ambient temperatures are higher. Eggs are laid between May and September in the northern hemisphere. They are deposited individually while the female digests her most recent blood meal. Unfertilized eggs remain in the ovarioles of females for the rest of their lives. (Grudemann, 1947)

  • Breeding interval
    Triatoma sanguisuga can breed repeatedly once it reaches sexual maturity.
  • Breeding season
    Triatoma sanguisuga breeds mainly during late spring and summer.
  • Range eggs per season
    5 to 17
  • Range age at sexual or reproductive maturity (female)
    1.5 to 2.5 years
  • Range age at sexual or reproductive maturity (male)
    1.5 to 2.5 years

Adults of Triatoma sanguisuga do not provide any parental care other than provisioning of eggs. Each yolk provides nutrients for the fertilized eggs. Females do not take care to lay eggs in any specific place, but instead, they are laid where the females digest their last blood meal. (Grudemann, 1947)

  • Parental Investment
  • pre-hatching/birth
    • provisioning
      • female

Lifespan/Longevity

In a laboratory setting, Triatoma sanguisuga is found to live for 450 days on average. However, in this experiment, the insects did not undergo hibernation phases. Consequently, in nature its life cycle would be approximately 3 years when including the hibernation periods. T. sanguisuga is able to survive for long periods on relatively few feedings, with lab populations living over 100 days on only three or four meals. (Grudemann, 1947)

  • Average lifespan
    Status: wild
    3 years
  • Average lifespan
    Status: captivity
    450 days

Behavior

Triatoma sanguisuga lives in colonies. Information regarding the number of individuals living in a colony was unavailable, however these colonies are typically founded by one female and her newest brood of eggs. Triatoma sanguisuga is active during the warmer months, hibernating through winter from late November to early March. The saliva it secretes during a bite functions as an anesthetic, allowing T. sanguisuga to feed for 3 to 8 minutes without alarming its host, which is usually sleeping. Whenever possible, it chooses to feed during the night and then hang upside down while digesting the blood meal. While nymphs avoid light, the adults are attracted to it, and use this sense to locate hosts.

After T. sanguisuga begins feeding, molting hormones are released into its blood stream and initiate its molting phase. However, if not given adequate time to feed and secrete these hormones, molting is disrupted and incomplete. Other behaviors characteristic to T. sanguisuga include the defecation schedule following feedings. First, it empties its fecal pouch following a feeding. Later, it defecates a large amount of excess liquid from the recent blood meal. Finally, it defecates a large quantity of hemoglobin. The protozoa Trypanosoma cruzi, which causes Chagas disease, is sometimes present in the feces of T. sanguisuga, but because T. sanguisuga does not defecate immediately and while still located on its host, it is not as significant a vector of Trypanosoma cruzi as other related species. (Encyclopedia Britannica, 2012; Grudemann, 1947; Stevens, et al., 2011)

Home Range

These insects have a small home range. Since they live in the nests of their hosts, they have little need to travel away from their homes. This convenience allows them to be relatively sedentary and to live in colonies. (Grudemann, 1947)

Communication and Perception

Triatoma sanguisuga, like other Triatomine bugs, uses a variety of sensory modalities to locate its prey. It detects carbon dioxide levels, host-specific odors, moisture gradients, heat, and air flow messages. Some hosts emit specific chemical cues or infrared radiation that it can follow as well. Most Triatoma species posses segmented antennae bearing sensing bristles called sensilla. The arrangement and morphology of the sensilla varies, but in general, they function as the organs for chemoreception. The sensilla density and patterns exhibit sexual dimorphism, also suggesting a role in reproduction sensation. (Catalá, 1997; Stevens, et al., 2011)

Triatoma sanguisuga has several ways to find hosts. It detects carbon dioxide levels, specific host smells, changes in moisture, heat, and changes in air flow. Some hosts produce specific chemicals or infrared radiation that T. sanguisuga can follow. Most Triatoma species have antennae with special bristles called sensilla. These sensilla are organs that detect chemicals. Since the pattern and amount of sensilla is different between males and females, they probably play a part in sensing a mate during reproduction. (Catalá, 1997; Stevens, et al., 2011)

Food Habits

Triatoma sanguisuga derives its name from its only food choice, blood meals. It typically lives within the nests of its host, so that a food source is always near. Its most common host is the wood rat, Neotoma floridana, but it is also known to bite humans, horses, and other small mammals. (Drees and Jackman, 1999; Grudemann, 1947)

  • Animal Foods
  • blood

Predation

Little information is available about animals that prey on Triatoma sanguisuga.

Ecosystem Roles

Triatoma sanguisuga is an obligate parasite that requires blood to complete its life cycle. It uses its proboscis to feed on blood from hosts that include eastern wood rats, horses, humans, and other small mammals such as raccoons and armadillos. While the bite made for feeding can go unnoticed, due to anesthetic in its saliva, a bite made in self-defense is painful and can cause swelling, dizziness, or nausea. Triatoma sanguisuga can act as a vector for Trypanosoma cruzi, a protozoan that causes Chagas disease, or viruses that cause equine enchephelomyelitis. Both of these pathogens can be fatal for the host. However, the defecation behavior of T. sanguisuga limit its risk of causing infection, as it does not defecate immediately while still on its host. ("Parasites - American Trypanosomiasis (also known as Chagas Disease)", 2010; Cesa, et al., 2011; Drees and Jackman, 1999; Encyclopedia Britannica, 2012; Grudemann, 1947; Stevens, et al., 2011)

Commensal/Parasitic Species
  • Trypanosoma cruzi

Economic Importance for Humans: Positive

There are no known positive effects of Triatoma sanguisuga on humans.

Economic Importance for Humans: Negative

Triatoma sanguisuga has been increasingly threatening to humans. Its primary nuisance is its blood feedings. It is also called the Mexican bed bug because it is known to feed at night. A third common name, the kissing bug, is earned because it tends to bite around the eyes and lips. In addition to the bite, T. sanguisuga is a confirmed vector for T. cruzi, a parasitic trypanosome that causes Chagas disease. The bite alone does not confer the parasite, but itching and allowing T. sanguisuga fecal material to enter the skin completes the transmission. Chagas disease is a serious and potentially lifelong disease, that at first can cause fever and swelling, and later can cause serious life threatening symptoms such as heart complications. This disease is most prevalent in Mexico, Central and South America, with as many as 11 million people infected. Triatoma sanguisuga can also transmit the virus that causes equine encephalomyelitis. ("Parasites - American Trypanosomiasis (also known as Chagas Disease)", 2010; Drees and Jackman, 1999; Grudemann, 1947; Kobylinski and Connelly, 2009)

Conservation Status

Triatoma sanguisuga has no special conversation status and is in no danger of extinction. The population is under control guidelines due to its role as a vector of Trypanosoma cruzi and consequential harm to humans. (Drees and Jackman, 1999; Encyclopedia Britannica, 2012; Stevens, et al., 2011)

Contributors

Laura Maurer (author), University of Michigan-Ann Arbor, Angela Miner (editor), Animal Diversity Web Staff.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

causes or carries domestic animal disease

either directly causes, or indirectly transmits, a disease to a domestic animal

chemical

uses smells or other chemicals to communicate

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

infrared/heat

(as keyword in perception channel section) This animal has a special ability to detect heat from other organisms in its environment.

internal fertilization

fertilization takes place within the female's body

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

parasite

an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

polymorphic

"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.

sanguivore

an animal that mainly eats blood

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

visual

uses sight to communicate

References

Centers for Disease Control. Parasites - American Trypanosomiasis (also known as Chagas Disease). n/a. Atlanta, Georgia: Center for Disease Control. 2010. Accessed February 06, 2012 at http://www.cdc.gov/parasites/chagas/gen_info/vectors/index.html.

Integrated Taxonomic Information System. Triatoma Sanguisuga. n/a. US, Canada, and Mexico: Integrated Taxonomic Information System. 1996. Accessed February 06, 2012 at http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=107473.

Borror, D., C. Triplehorn, N. Johnson. 1989. An Introduction to the study of Insects. Philadelphia, PA: Saunders College Publisher.

Catalá, S. 1997. Antennal sensilla of Triatominae (Hemiptera, Reduviidae): A comparative study of five genera. International Journal of Insect Morphology and Embryology, 26/2: 67-73.

Cesa, K., K. Caillouet, P. Dorn, D. Wesson. 2011. High Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae) Prevalence in Triatoma sanguisuga (Hemiptera: Redviidae) in Southeastern Louisiana. Journal of Medical Entomology, 48/5: 1091-1094.

Dorn, P., L. Perniciaro, M. Yabsley, D. Roellig, G. Balsamo, J. Diaz, D. Wesson. 2007. Autochthonous Transmission of Trypanosoma cruzi, Louisiana. Emerging Infectious Diseases, 13/4: 605-607.

Drees, B., J. Jackman. 1999. "Kissing Bug, Conenose Bug, Masked Hunter" (On-line). AgriLIFE Extension. Accessed February 06, 2012 at http://insects.tamu.edu/fieldguide/aimg53.html.

Encyclopedia Britannica, 2012. Assassin Bug (insect). Pp. n/a in Encyclopædia Britannica Online, Vol. n/a, n/a Edition. n/a: n/a. Accessed March 24, 2012 at http://www.britannica.com/EBchecked/topic/39144/assassin-bug.

Grudemann, A. 1947. Studies on the Biology of Triatoma Sanguisuga in Kansas. The Journal of the Kansas Entomological Society, 20/3: 77-85. Accessed February 06, 2012 at http://www.k-state.edu/parasitology/articles/Triatoma-01.pdf.

Klotz, S., P. Dorn, J. Klotz, J. Pinnas, C. Weirauch, J. Kurtz, J. Schmidt. 2009. Feeding behavior of triatomines from the southwestern United States: An update on potential risk for transmission of Chagas disease. Acta Tropica, 111/2: 114-118.

Kobylinski, K., R. Connelly. 2009. "Blood Feeding Insect Series: American Trypanosomiasis - Chagas Disease" (On-line). University of Florida Department of Agriculture. Accessed February 06, 2012 at http://edis.ifas.ufl.edu/in650.

Roden, A., D. Champagne, B. Forschler. 2011. Biogeography of Triatoma sanguisuga (Hemiptera: Reduviidae) on Two Barrier Islands off the Coast of Georgia, United States. Journal of Medical Entomology, 48/2: 806-812.

Stevens, L., P. Dom, J. Schmidt, J. Klotz, D. Lucero, S. Kotz. 2011. Kissing Bugs. The Vectors of Chagas. Advances in Parasitology, 75/na: 169-192.

Wild, A. 2012. "The Friendly Face of Triatoma Sanguisuga" (On-line image). Alex Wild Photography. Accessed February 06, 2012 at http://www.alexanderwild.com/Insects/Bountiful-Bugs/4191931_FWpfRM/1491542895_hmSJTS2#!i=1491542895&k=hmSJTS2.

de la Rua, N., L. Stevens, P. Dorn. 2011. High genetic diversity in a single population of Triatoma sanguisuga inferred from two mitochondrial markers: Cytochrome b and 16S ribosomal DNA. Infection, Genetics and Evolution, 11/3: 671-677.