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)
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)
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)
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)
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)
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)
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)
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)
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)
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)
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)
Little information is available about animals that prey on Triatoma sanguisuga.
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)
There are no known positive effects of Triatoma sanguisuga on humans.
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)
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)
Laura Maurer (author), University of Michigan-Ann Arbor, Angela Miner (editor), Animal Diversity Web Staff.
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.
living in the southern part of the New World. In other words, Central and South America.
uses sound to communicate
living in landscapes dominated by human agriculture.
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.
an animal that mainly eats meat
either directly causes, or indirectly transmits, a disease to a domestic animal
uses smells or other chemicals to communicate
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.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
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.
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.
(as keyword in perception channel section) This animal has a special ability to detect heat from other organisms in its environment.
fertilization takes place within the female's body
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).
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.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death
chemicals released into air or water that are detected by and responded to by other animals of the same species
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
"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.
an animal that mainly eats blood
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
living in residential areas on the outskirts of large cities or towns.
uses touch to communicate
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).
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
living in cities and large towns, landscapes dominated by human structures and activity.
uses sight to communicate
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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.