It is apparent that this emerging pathogenic agent has started to perpetuate within the states of which was endemic to the south. The agent owes it's success of infiltration to its accompanying arthropod vector. It is important to learn the behaviors, geographical distributions, it's biology, etc. in order to obtain leverage against the vector and pathogen.

 

        The pathogen's competent arthropod vector belongs to the most diverse order of insects, Hemiptera. The order within itself offers a wide range of insects that could not support this agent. It has been found that only a very specific arthropod in the Triatoma genus could vector the agent in high enough concentrations to infect the host. With the descriptions the patients gave of the insects they came in contact with we were able to identify the vector down to the species level. In our research it was Triatoma Recurva that subjected the patients to the untreatable agent that resulted in their deaths. In order to identify this insect, it might help to consider some of the following key characteristics as noted by the CDC.

 

 

 

 

 

 

 

   

 

      This species of insects is closely associated with rodent burrows, living in their habitats until they are ready for a blood meal or a dispersal flight. They have been specifically found in invertebrate burrows in rock slides and boulder piles (Ryckman, Christianson, Spencer, 1955). In another study (Ekkens 1981) it was found that T. recurva could be found in rocky slopes inhabited by chipmunks, Western Spotted Skunks, Rock Squirrels and lizards in 14:1 male to female ratio. However this species is no limited to the confines of their habitats, due to their vectoring capabilities T. recurva could be living with or around humans. Not only are their habitats sylvatic, but are living peridomestically. (Pfeiler et al. 2005). The only time they will be outside their habitat is when the insect is starved, a period of about two weeks without feeding, that they will ignore their habitat, seek a blood meal and will immediately begin feeding ( Kotz et al. 2013).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

        In a separate study, (Martinez-Ibarra et al. 2011) it was found that for all nymphal instars can take anywhere from about 18 seconds up to 3 minutes to initiate feeding. Meaning that under normal conditions, given that the insect is not starved, once introduced to the host they will sit on the host for a moment before feeding. In order for a newly emerged nymph to reach their adult form they must go through 5 nymphal instars and will need on average 3.5 blood meals before molting as seen in Fig. 3 below. T. recurva. Like all of the Triatoma genus it goes through imcomplete metamorphosis, only obtaining a full pair of wings at the adult stage. Each of the nymphal blood meals, regardless of instar stage, will have a mean feeding time of about 10 minutes and both sexes of adults go well above the 10 minute mark. It is clear that for five nymphal stages that it's a quite large number of blood meals. But pehaps that could be explained by the long developmental time T. recurva requires to reach it's adult form. T. recurva will easily take more than eight and a half months to go though their whole egg-to-adult development. Lastly, less that 10% of these guys will defecate while feeding, and those that do will within 10 minutes while feeding.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

        Now that their blood meal requirements are explained, we will cover how many of these guys actually make it to their adult form. In the same blood meal study (Martinez_Ibarra et al. 2011) it was found that T. recurva females will easily lay out 200 eggs on average. Of that totality, statistically 66% of those will hatch and that 34% of those eggs will not. Of those that hatched, most generally seem to make it to the 5th instar with no problems. However those nymphs that die before reaching their 5th instar is due to their inability to feed. It is at the fifth instar that the highest mortality rate is observed.

 

        So what do they feed on? Although their habitats are in conjunction with that of invertebrate rodents, T. recurva does not limit itself to humans (Ekkens 1981). As said before, they inhabit rocky slopes with chipmunks, Western Spotted Skunks, etc. on which they will feed on occasion. This means that unlike other Triatoma species, they are more generalist feeders. When it comes to humans (Kotz et al. 2013) T. recurva gain access to our homes and feed on us and our pets, often for months before we even notice that they are there. Our failure to notice their presence is due to their painless bite and feeding on three different hosts on average. They are attracted to lights during the night time, and gain access to people's homes through the lower thresholds of the doors and window casings. If given the opportunity, these insects will make use of their painless bites and feed on humans outside of their homes, this is mostly seen in the desert southwest of the U.S. Their biggest source of food however is definitely us. We constitue the largest biomass of their food source.

 

        T. recurva take into account several environmental factors before initiating dispersal flights. This is collectively seen in a few studies (Ekkens 1981, Kotz 2013). It was found that temperature had an effect in their decision to spread throughout environments. In the temperature range of 26-33 degrees celsius they would display random frequencies of dispersal. However at temperatures above 36 and below 26 degrees celsius dispersal of T. recurva was not observed. Time of day is also very important to consider, 88% of these creatures choose to take part in dispersal flights during the first hour after dark. When it comes to weather, rain fall is believed to inhibit their ability to disperse successfully. As a result T. Recurva will disperse before onset of the summer rains and monsoon rains. Low humidity and wind movement will also influence their dispersal, wind speeds of 0-12.8 km/h are favorable for flight. Any speeds above that rate does not inhibit their dispersal but are very rarely observed. Anytime within the months of May and June under favorable conditions one can observe the highest amount of dispersal flights, honing in on lights to seek refuge indoors.

 

        The geographical range of T. recurva (Ryckman et al. 1955, Pfeiler et al. 2005) for the purposes of our investigation, has been noted in the northern states of Mexico and have been known to reside in desert regions of south Arizona extending to the southwestern part of the United States. Some northwestern states of Mexico where T. recurva is commonly found is Chihuahua, Nayarit, Sinaloa, and Sonara which consist a large portion of their range. Globally (Cotinis 2004) Triatoma is pantropical and transcontinental, found anywhere from the southwestern part of the Unites States down to Argentina.