Triatoma sanguisuga is on average 22 mm long. It has an oval-shaped black body with red stripes on the outer edge of the body. Its two back legs are twice as long as its four front legs. It has a narrow head, with large eyes that stick out. T. sanguisuga has a long mouth called a proboscis that is used to poke through the skin of an animal and suck its blood. It has sensory organs on the antennae, called sensilla. These sensory organs are different on males and females. Males have more of them and in different patterns than females. Nymphs of this species look the same as adults, except smaller and without wings. Eggs are small, white ovals measuring between 1 to 2 mm.
Different populations in different regions of this species can look different, despite being the same species. This is because these populations are separated and have developed different characteristics over time. (Catalá, 1997; Klotz, et al., 2009; Roden, et al., 2011; Stevens, et al., 2011; Wild, 2012)
Triatoma sanguisuga is found in the southeastern United States and throughout Latin America. This range includes both the Nearctic and Neotropical regions. Its range in North America spreads from Pennsylvania to Florida and as far west as Arizona. Most research about this insect is on populations in the United States, so the range in Latin America is unknown. (Cesa, et al., 2011; Dorn, et al., 2007; Kobylinski and Connelly, 2009)
Triatoma sanguisuga is found in wooded environments where small mammals live. These insects suck the blood of small mammals, with wood rats being the most common source of blood. The rat nests provide a home for Triatoma sanguisuga. The rat nests are built around large flat rocks, decaying matter, and wood piles. These insects live, feed, and lay eggs safely in these nests. Triatoma sanguisuga also nests in human buildings or farms when sucking the blood of other animals. It can be found under loose wooden floorboards and older building structures. (Encyclopedia Britannica, 2012; Grudemann, 1947)
Triatoma sanguisuga has incomplete metamorphosis. It goes through egg, nymph, and adult life stages. The eggs of Triatoma sanguisuga are laid once the female has been fertilized by a male and has taken a blood meal from a host. The time it takes for eggs to hatch depends on temperature, with warmer temperatures causing a shorter time to hatch. A nymph finds a blood meal 2 to 3 days after hatching. Nymphs have several stages called instars, and they look like smaller version of adults, without wings. During the nymphal stage, T. sanguisuga undergoes ecdysis, which are many cycles of shedding its exoskeleton. Each instar stage is separated by a molt. Nymphs molt after they have eaten and digested their blood meal. This causes a molting hormone to be released in the body, which causes the molting. Nymphs that are born early in the season can go through five instar stages. They then go into hibernation for the winter, where they are awake but sluggish and do not move much. After coming out of hibernation in the spring, the nymph completes the rest of its instar stages, if it did not complete those in the previous summer. After 8 nymphal instars, it becomes an adult. (Grudemann, 1947; Stevens, et al., 2011)
Females and males are polygynandrous, meaning that both males and females will mate many times with many mates during their lives. The mating time of T. sanguisuga lasts only 10 minutes. After mating, females move to a new territory to start a new community. (Stevens, et al., 2011)
Females lay eggs after they have been fertilized by a male and after the females have taken a blood meal from a host. A female can lay hundreds of eggs during her life. The amount of eggs laid depends on several things. More eggs are laid when temperatures are higher. It also depends on how much space is available, and the host used for the blood meal. Eggs are laid between May and September in the northern hemisphere. They are laid one at a time while the female digests her most recent blood meal. (Grudemann, 1947)
Females provide nutrients in the eggs for the offspring to use to grow and develop before hatching. Otherwise, adults of Triatoma sanguisuga do not provide any parental care. Females do not lay eggs in any specific, safe place to nymphs to hatch, but instead eggs are laid wherever females digest their last blood meal. (Grudemann, 1947)
In a laboratory, Triatoma sanguisuga can live for 450 days on average. However, these insects do not go into hibernation while in a laboratory. In the wild, when T. sanguisuga does go through hibernation, it can live about 3 years. These insects can live for so long because they can live for long periods with only a few blood meals. Populations in laboratories could live over 100 days on only three or four meals. (Grudemann, 1947)
Triatoma sanguisuga lives in large groups, called colonies. Colonies are usually started by one female and her newest group of eggs. T. sanguisuga is active during the warmer months, and goes into hibernation during the winter from late November to early March. When it bites an animal to feed on its blood, the saliva from T. sanguisuga acts as an anesthetic. This means that the animal being bitten does not feel the bite. This allows Triatoma sanguisuga to feed for 3 to 8 minutes without the host noticing. T. sanguisuga usually feeds during the night on animals that are sleeping, and after eating, it hangs upside down while digesting. Adults are attracted to light, and use it to locate host animals. Nymphs usually stay away from light.
One behavior that is unique to T. sanguisuga is the defecation schedule following blood feedings. First, it empties its fecal pouch after a feeding. Later, it defecates a lot of extra liquid from the recent blood meal. Finally, it defecates a large amount of hemoglobin. Hemoglobin is found in the blood of vertebrates, and it carries oxygen from lungs or gills to the rest of the body. T. sanguisuga can sometimes carry the protozoa Trypanosoma cruzi, which causes Chagas disease in humans, in its feces. Since T. sanguisuga has a unique defecation schedule and waits to defecate, it does not defecate on the host. This prevents Trypanosoma cruzi from infecting humans or other animals at a high rate, since the feces containing the protozoa are usually defecated in places nowhere near a host. (Encyclopedia Britannica, 2012; Grudemann, 1947; Stevens, et al., 2011)
These insects have a small home range. Since they live in the nests of their rat hosts, they do not need to travel away from their homes, since food and shelter are all in one place. This allows Triatoma sanguisuga to stay mostly in one place and to live in large groups. (Grudemann, 1947)
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 eats only one thing: the blood of other animals. It usually lives within the nests of the animals it bites, so that food 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 a parasite that requires blood to complete its life cycle. It uses its long mouth, the proboscis, to feed on blood from animals that include eastern wood rats, horses, humans, and other small mammals such as raccoons and armadillos. Since T. sanguisuga has anesthetic in its saliva that prevents pain, animals usually do not notice when these insects are feeding. However, when T. sanguisuga bites in self-defense, the bite can be painful and cause swelling, dizziness, or nausea. Triatoma sanguisuga can carry the protozoa Trypanosoma cruzi, which causes Chagas disease in humans. It can also carry viruses that causes equine enchephelomyelitis in horses and humans. Both of these can be fatal. However, the defecation schedule of T. sanguisuga decreases its risk of causing disease, as it does not defecate while still on its host, but instead defecates later. This is important because Trypanosoma cruzi is present in its feces. ("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)
Triatoma sanguisuga has become more and more of a threat to humans. It can use humans as a host and feed on their blood. It is also called the Mexican bed bug because it usually feeds at night. It has a third common name, the kissing bug, because it bites humans around the eyes and lips. In addition to bites, T. sanguisuga can transmit Trypanosoma cruzi, which is a tiny parasitic organism that causes Chagas disease in humans. Trypanosoma cruzi is present in the feces of T. sanguisuga. It can infect a person when the itching and scratching of a bite from T. sanguisuga causes feces to enter the skin. Chagas disease is a serious disease and can be lifelong. At first, it can cause fever and swelling, and later can cause serious life threatening symptoms such as heart problems. This disease is most common 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.
There are no known positive effects of Triatoma sanguisuga on humans.
Triatoma sanguisuga is not an endangered species. The population of these insects is under control guidelines because it can infect humans with Trypanosoma cruzi and cause Chagas disease, which can be fatal. (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.
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.
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.