Instars: A Journal of Undergraduate Research (Texas Digital Library - TDL E-Journals)
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Ticks, the Ultimate Parasite
No full textTicks are notorious vectors of disease causing pathogens such as the pathogens that cause Lyme disease, Rocky Mountain spotted fever, and tick paralysis. Ticks are second only to mosquitoes in terms of public health importance. Ticks are found in many climates around the world but tend to frequent warmer areas with higher humidity (Centers for Disease Control and Prevention). In conjunction with a local humane society samples of ticks were collected from various dogs. Five ticks were collected, an Ixodes scapularis (Arachnida: Acari: Ixodidae: L.), two Amblyomma americanum (Arachnida: Acari: Ixodidae: L.) and two Dermacentor variabilis (Arachnida: Acari: Ixodidae: L.). Findings from this survey imply that there are possible tick vectors within the Brazos Valley Area.
A Comparison of Mosquito Species in Developed and Undeveloped parts of the College Station/Bryan Area in the Brazos County, Texas
No full textMosquitoes are the deadliest vectors of human diseases, but are often unable to fly far distances from their place of emergence. Developed areas may have different species than nearby undeveloped areas due to this attribute of weak flying. This experiment involved setting out water sources at two nearby sites at each of three locations. These sites were then sampled for larvae that were identified. We identified Culex restuans (Theobald) (Diptera: Culicidae) at every single site (besides Location 3 Site 1 where our bucket was stolen). We also identified Toxorhynchites rutilus (Coquillett) (Diptera: Culicidae) at Location 1 Site 2. There was not enough information to determine a pattern with our data. It is suggested that more data be collected during years with more standard weather.
Alternative IPM Methods for Varroa destructor (Parasitiformes: Varroidae) (Anderson and Trueman) Mite Control in East Texas apiaries
No full textThe parasitic mite Varroa destructor (Anderson and Trueman) is a major pest of the honey bee (Apis mellifera (L.)), because large quantities of the mites can cause colony collapse disorder. Over the last two decades, prophylactic treatment of V. destructor using pyrethroid and organophosphate chemicals has caused increased resistance, requiring higher maintenance and treatment costs for beekeepers. This study examines the therapeutic effects of three different IPM methods for the control of V. destructor in two apiaries in East Texas. 24 colonies were separated into four different groups: untreated control colonies, colonies in which the queens were caged, colonies treated with powdered sugar using the “Dustructor” apparatus (Brushy Mountain Bee Farm, Moravian Falls, NC), or colonies treated with thymol (active ingredient ApiLife Var® (Mann Lake Ltd., Hackensack, MN)). V. destructor populations in each colony were monitored for 54 days using the powdered sugar shake method or via a sticky board hung up for 24-hours. Powdered sugar shake mite counts reflected lower populations of V. destructor in all colonies treated with any of the three IPM methods compared to those of the untreated controls. Conversely, sticky board mite counts showed no statistical difference in mite counts based on IPM treatments compared to untreated controls. These results suggest that the powdered sugar shake method is more accurate when monitoring V. destructor populations than the 24-hour sticky board method. Alternative IPM methods for V. destructor control are effective and serve as a promising new avenue for non-intrusive control of this major honey bee pest.
The Accelerating Effects of Burning on Carrion Decomposition
No full textIn some homicide cases, the victim\u27s body is burned. There is little data that suggests that burned organic tissue decomposes at a faster rate than unburned tissue. This experiment used chickens to test if the burning of tissue had a faster decomposing affect than unburned tissue. Decomposition rate was examined through how many insects were on the carcasses in different amounts of sunlight. It was determined that a burned carcass, where there is some sunlight, decomposes faster than an unburned carcass. This information could be used to determine the time of death of a victim that was burned after death.
The Effect Ethyl Alcohol has on Insect Colonization/Decomposition of Exposed Chickens Reveals Postmortem Interval Estimations May Be Influenced
No full textPostmortem Interval Estimations are made using clues from the development of colonizing insects found on the individual. Insects are drawn to these bodies by chemical cues due to decomposition of the body. Many times in the forensics, the body has been burned, or in some way altered to make estimations difficult for investigators by altering the decomposition process, or effecting the colonization rate of insects to the body. To determine the effect of ethyl alcohol on insect colonization/decomposition, decomposing chickens that were previously soaked in 200 proof ethyl alcohol were compared to decomposing control chickens that were not soaked in alcohol. Insects in the orders Diptera and Coleoptera were collected and identified. Results from our experiment were also compared to other groups performing the same experiment in order to find further similarities or differences
Cattle Production Loss Due to Caelifera (Orthoptera) in the State of Texas
No full textThe purpose of this experiment is to calculate the cattle production loss created by grasshoppers in the state of Texas. Grasshoppers create a significant deficit in cattle feed yearly which thereby leads cattle production loss for ranchers. Our (The) study involves the use of two species of grasshoppers, Chorthippus parallelus (Brown pg.32) and Camnula pellucida(Helfer pg 108), a one hundred fifty acre plot, and seventy-two head of cattle. Specimens were collected off a portion of the acreage. An average overhead was estimated for the feed deficit. Crop loss was then calculated with environmental and entomological factors taken into account. The results of this experiment showed a much larger overhead than originally predicted and the staggering effects of Caelifera on small cow and calf operations. This study could be used to further research the annual cattle production deficit on larger cattle operations such as King Ranch or stocker calf operations all over Texas, which are dependent upon rangeland for grazing cattle. The estimated results indicate that the grasshoppers are eating 14,417.5 pounds of dry matter more than the cattle are per yea
The Impact of College Station, Texas Weather Trends on Mosquito Populations
No full textMosquitoes pose a significant threat to human society medically, as a competent vector of diseases such as Malaria and Yellow fever, and economically by vectoring diseases to commercial domestic animals that harm and may lead to death, dealing great losses to such companies. With such importance, the need for greater knowledge on the life cycles of mosquitoes is invaluable in the fight to eradicate and control mosquitoes. The goal of this study was to survey the College Station landscape and area surrounding Texas A&M University to determine the species and genus of mosquitoes found to inhabit the area as well as the weather trends during the time of mosquito collection to observe the effects such trends may have on the mosquito populations. During the period of February-March this year, the average temperature was lower than what was seen in previous years. Furthermore, during the month of April lower temperatures had continued to sporadically occur, which led to the disruption in the abundance of mosquitoes seen around this time in previous years. Due to the abnormal weather patterns that were experienced in this region of Texas this year, the mosquito population has been greatly lacking in numbers up until late April. During our survey and collection the largest number of individuals were of the Culex genus, with several Culiseta species also found.
Effects of 24-hour postmortem ethanol soaked chicken on insect succession
No full textIn the field of forensic entomology, experts are most frequently called upon to determine a minimum postmortem interval (PMI) for victims of death investigations. Many factors have a repellent effect on arthropod attraction to carrion, affecting the PMI, and this study examined the effects of soaking remains in ethanol for 24 hours before the body was made available for colonization. Eight whole chicken carcasses were used in this experiment. Four were used as controls and four were experimental carcasses soaked in ethanol for 24 hours. All chickens were taken into the field and remained for 7 days in wire cages. Arthropod specimens were collected and identified. Sarcophagidae larvae were the most abundant on both the control and test chickens. Five families of beetles were collected from the control and test chickens. Adult fly populations couldn’t be distinguished between either the test or control chickens. No significant difference in insect succession between the control and experimental chicken was observed. However, there was a difference in gross decomposition between the control and experimental chickens. Further studies are needed to examine the behavior of adult flies with regard to colonization of ethanol-soaked chickens
Mosquito Surveillance in the Brazos County (Diptera:Culicidae)
No full textMosquitoes are the most dangerous animals in the planet. They are known vector of some diseases like Malaria and Dengue. It is important to know what species of mosquitoes are presented in the area since not all of them vector the same diseases. The goals of this experiment was to identify the various species of Culicidae (Diptera) in the Bryan College Station area, in addition we noted the effect of climate on the prevalence of these species. Mosquito larvae were collected twice a week at three different locations. These collected larvae were separated into two groups- those to be maintained as larval specimens and those to be reared and identified as adults. By correctly identifying the adults, the potential to assert the most effective prevention methods for the Bryan College Station could potentially be achieved. In addition, studying the effects of climate on the population dynamics of mosquitoes can help determine the most efficient times to provide preventative treatments to the Bryan College Station area. This experiment will serve to identify the various species and the effects of climate on these species within the Bryan College Station area, in an effort to determine the most effective preventative measures.
A Survey of Mosquito Populations in the Bryan-College Station Area
No full textSome species of mosquitos can be vectors of serious diseases that can not only cause death, but a significant amount of monetary lost. This survey was performed with the goal of discovering which species of mosquitoes are present in the Bryan-College Station area so that knowledge could be gained on potential disease vectors in the community. This survey was accomplished through frequent larvae sampling from pools of water in various locations. Samples of larvae were collected using plastic bottles and adults were collected using an insect net. Larvae were reared into adults using a mosquito breeder. These adults were then placed into a kill jar to allow proper identification. Based on previous studies, it was expected that there would be a number of medically important mosquito species which vector common diseases that are prevalent in this part of the country. The conducted survey found two common genera from the collected larvae and adult mosquitoes: Aedes and Culex. Specifically, Aedes aegypti (L.) (Diptera: Culicidae) was found to be the most prominent species in the Bryan-College Station area. It is important to understand that our results could have been affected by the low temperatures and drought experienced this year