Triatoma gerstaeckeri
Triatoma gerstaeckeri is an assassin bug in the genus "Triatoma" (kissing bugs). It is an important vector of "Trypanosoma cruzi", the causative agent of Chagas disease. The range of "T. gerstaeckeri" is from the south-western United States (New Mexico, Texas) and north-eastern Mexico. "T. gerstaeckeri" goes through three stages during its paurometabolous life cycle: egg, nymphal instars and adult. 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 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 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. Other "Triatoma" species are found throughout the United  States. In Texas, 63% of the "T. gerstaeckeri" identified were found near houses. 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 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, organ donation 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 raccoons, opossums, humans and dogs are also common. There  is no vaccine for Chagas Disease, so to decrease the prevalence of the disease, the spread of the "T. gerstaeckeri" and other Triatomine bugs must be limited. Development and life cycle. "T. gerstaeckeri" undergoes gradual metamorphosis (paurometabolous development) which means that there are three stages to its life cycle: egg, nymph 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.