''Triatoma gerstaeckeri'' is an

assassin bug The Reduviidae is a large cosmopolitan family of the suborder Heteroptera of the order Hemiptera (true bugs). Among the Hemiptera and together with the Nabidae almost all species are terrestrial ambush predators; most other predatory Hemiptera ...

in the genus ''

Triatoma ''Triatoma'' is a genus of assassin bug in the subfamily Triatominae (kissing bugs). The members of ''Triatoma'' (like all members of Triatominae) are blood-sucking insects that can transmit serious diseases, such as Chagas disease. Their saliva ...

'' (kissing bugs). It is an important vector of ''

Trypanosoma cruzi ''Trypanosoma cruzi'' is a species of parasitic euglenoids. Among the protozoa, the trypanosomes characteristically bore tissue in another organism and feed on blood (primarily) and also lymph. This behaviour causes disease or the likelihood ...

'', the causative agent of

Chagas disease Chagas disease, also known as American trypanosomiasis, is a tropical parasitic disease caused by ''Trypanosoma cruzi''. It is spread mostly by insects in the subfamily Triatominae, known as "kissing bugs". The symptoms change throughout the ...

.Kjos, Sonia A., Paula L. Marcet, and Ellen M. Dotson. "Identification of Bloodmeal Sources and Trypanosoma Cruzi Infection in Triatomine Bugs from Residential Settings in Texas, the United States." Journal of Medical Entomology 50.5 (2013): 1126-127. Web of Science. Web. The range of ''T. gerstaeckeri'' is from the south-western United States (

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

) to north-eastern Mexico.Sandoval-Ruiz, César A., Luis Cervantesperedo, Fredy S. Mendoza-Palmero, and Sergio Ibáñez-Bernal. "The Triatominae (Hemiptera: Heteroptera: Reduviidae) of Veracruz, Mexico: Geographic Distribution, Taxonomic Redescriptions, and a Key." Zootaxa 3487 (2012): 16. Web."Triatoma Gerstaeckeri." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 02 Nov. 2010. Web. 30 Oct. 2013. ''T. gerstaeckeri'' goes through three stages during its paurometabolous life cycle: egg, nymphal instars and adult.Pippin, Warren F. "The Biology and Vector Capability of Triatoma Sanguisuga Texana Usinger and Triatoma Gerstaeckeri (Stal) Compared with Rhodnius Prolixus (Stal) (Hemiptera: Triatominae)." Journal of Medical Entomology 7 (1970): 30+. Web.

Physical characteristics

''T. gerstaeckeri'' is between 20 and 30 mm long when fully developed. It is all black except for their yellow horizontal lines outside of the

pronotum The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum (dorsal), the prosternum (ventral), and the propleuron (lateral) on e ...

. The tip of its mouthparts have hairs, but the rest of the mouthparts do not. ''T. gerstaeckeri'' have long, narrow legs and a flat head. The first segment of its antennae is shorter than the clypeus on the insect's head. ''T. gerstaeckeri'' have

tubercles In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. In plants A tubercle is generally a wart-like projection, b ...

on its sides, and it has a round posterior that is very wrinkly. It has black forewings that cover the abdomen; the base of these forewings are yellowish orange.

Habitat

''T. gerstaeckeri'' is mostly found in the dry climates of northern Mexico, southern/central Texas and New Mexico where there is a lot of scrubby vegetation.Crawford, Britnee A., and Christopher M. Kribs-Zaleta. "Vector Migration and Dispersal Rates for Sylvatic Trypanosoma Cruzi Transmission." Ecological Complexity 14 (2013): 146-47. Web. Other ''Triatoma'' species are found throughout the United States. In Texas, 63% of the ''T. gerstaeckeri'' identified were found near houses.Sonia, Kjos A., Karen F. Snowden, and Jimmy K. Olson. "Biogeography and Trypanosoma Cruzi Infection Prevalence of Chagas Disease Vectors in Texas, USA." Vector-Borne and Zoonotic Diseases 9 (2009): 44+. Web. Out of 156 specimens of ''T. gerstaeckeri'' tested for the presence of ''T. cruzi'' in Texas, 55% were infected. In Mexico, 94% of the ''T. gerstaeckeri'' identified were found near houses.

Role in disease

''T. gerstaeckeri'' is a reservoir for the parasite ''T. cruzi'', which causes Chagas Disease. This is a very relevant disease in the Western Hemisphere because there are about 56,000 new incidents of Chagas Disease every year and about 12,000 deaths annually caused by this disease. All blood-feeding

arthropods Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

in the genus ''Triatoma'' are vectors of ''T. cruzi'', so these numbers are not caused by ''T. gerstaeckeri'' alone. Chagas Disease is spread when an infected triatomine defecates on or near a host, causing the parasite to enter the body of the host, usually through the site of a wound. This is usually how ''T. cruzi'' is transmitted, but it can also occur during

blood transfusion Blood transfusion is the process of transferring blood products into a person's Circulatory system, circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used ...

organ donation Organ donation is the process when a person authorizes an organ (anatomy), organ of their own to be removed and organ transplantation, transplanted to another person, #Legislation and global perspectives, legally, either by consent while the d ...

or the consumption of contaminated food or drink. ''T. cruzi'' is not transmitted directly by biting. The most common animal hosts of ''T. gerstaeckeri'' are woodrats, but

raccoon The raccoon ( or , ''Procyon lotor''), sometimes called the North American, northern or common raccoon (also spelled racoon) to distinguish it from Procyonina, other species of raccoon, is a mammal native to North America. It is the largest ...

opossums Opossums () are members of the marsupial order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 126 species in 18 genera. Opossums originated in South America and entered North A ...

human Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

s and

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers. ...

s are also common. There is no

vaccine A vaccine is a biological Dosage form, preparation that provides active acquired immunity to a particular infectious disease, infectious or cancer, malignant disease. The safety and effectiveness of vaccines has been widely studied and verifi ...

for Chagas Disease, so to decrease the prevalence of the disease, the spread of the ''T. gerstaeckeri'' and other Triatomine bugs must be limited.Sarkar, Sahotra, Stavana Strutz, Chissa-Louise Rivaldi, Blake Sissel, David Frank, and Victor Sanchez-Cordero. "Chagas Disease Risk in Texas." NCBI. N.p., 5 Oct. 2010. Web.

Development and life cycle

''T. gerstaeckeri'' undergoes gradual metamorphosis (paurometabolous development) which means that there are three stages to its life cycle: egg,

nymph A nymph (; ; sometimes spelled nymphe) is a minor female nature deity in ancient Greek folklore. Distinct from other Greek goddesses, nymphs are generally regarded as personifications of nature; they are typically tied to a specific place, land ...

and adult. The life cycle of ''T. gerstaeckeri'' begins when the female lays eggs. The eggs of ''T. gerstaeckeri'' are white when laid, but turn light pink shortly thereafter. The weight range of the eggs is from .832 mg to 1.125 mg. Female ''T. gerstaeckeri'' lay more eggs when there are changing temperatures, but a higher percentage of eggs hatch if there is a constant temperature. Females lay eggs for the duration of their life. Next, ''T. gerstaeckeri'' goes through a series of molts. There are five of these sub-stages in the life cycle of ''T. gerstaeckeri'', called its five nymphal instars. The time of development for all stages is longer when temperatures are dropped. The average development time of egg through fifth instar for ''T. gerstaeckeri'' at 27 degrees Celsius is 213.9 days; with the temperature range from 18 to 30 degrees Celsius these same stages took an average of 361.9 days to develop. The highest percentage of nymphs molted when their blood meals were from mammals, particularly squirrels. The percentage weight gain for ''T. gerstaeckeri'' due to blood feeding is highest during the first instar. ''T. gerstaeckeri'' then become adults and individuals mate and reproduce to start the cycle over again. ''T. gerstaeckeri'' has a life cycle of nine to fourteen months.

References

Notes

* Crawford, Britnee A., and Christopher M. Kribs-Zaleta. "Vector Migration and Dispersal Rates for Sylvatic Trypanosoma Cruzi Transmission." Ecological Complexity 14 (2013): 146–47. Web. * Kjos, Sonia A., Paula L. Marcet, and Ellen M. Dotson. "Identification of Bloodmeal Sources and Trypanosoma Cruzi Infection in Triatomine Bugs from Residential Settings in Texas, the United States." Journal of Medical Entomology 50.5 (2013): 1126–127. Web of Science. Web. * Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. "Animal Diversity Web." ADW: Triatoma Gerstaeckeri: CLASSIFICATION. Regents of the University of Michigan, 2012. Web. 24 Oct. 2013. * Pippin, Warren F. "The Biology and Vector Capability of Triatoma Sanguisuga Texana Usinger and Triatoma Gerstaeckeri (Stal) Compared with Rhodnius Prolixus (Stal) (Hemiptera: Triatominae)." Journal of Medical Entomology 7 (1970): 30+. Web. * Sandoval-Ruiz, César A., Luis Cervantesperedo, Fredy S. Mendoza-Palmero, and Sergio Ibáñez-Bernal. "The Triatominae (Hemiptera: Heteroptera: Reduviidae) of Veracruz, Mexico: Geographic Distribution, Taxonomic Redescriptions, and a Key." Zootaxa 3487 (2012): 16. Web. * Sarkar, Sahotra, Stavana Strutz, Chissa-Louise Rivaldi, Blake Sissel, David Frank, and Victor Sanchez-Cordero. "Chagas Disease Risk in Texas." NCBI. N.p., 5 Oct. 2010. Web. * Sonia, Kjos A., Karen F. Snowden, and Jimmy K. Olson. "Biogeography and Trypanosoma Cruzi Infection Prevalence of Chagas Disease Vectors in Texas, USA." Vector-Borne and Zoonotic Diseases 9 (2009): 44+. Web. * "Triatoma Gerstaeckeri." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 02 Nov. 2010. Web. 30 Oct. 2013. {{Taxonbar, from=Q10702253 Reduviidae Insect vectors of human pathogens Hemiptera of North America Insects described in 1859