Instars: A Journal of Undergraduate Research (Texas Digital Library - TDL E-Journals)
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Survey of the Culex quinquefasciatus (Diptera: Culicidae) Mosquito and the Transmission of West Nile Virus in Brazos County
No full textLocalities in the College Station area of Texas were surveyed for Culicidae species to examine the prevalence of Culex quinquefasciatus. A recent outbreak of West Nile Virus (WNV) in a nearby suburb of Houston caused by salvarian transmission of Culex q. deems it a medically significant vector worthy of surveillance. Mosquito specimens were collected using Center of Disease Control (CDC) light traps in various recreational parks with proximity to water and moderate human activity, as is preferred by the organism. Collection procedures were implemented during warm, humid months due to mosquito populations peaking at this time. Through trapping, preservation, and identification with pictorial keys, the prevalence of Culicidae species was determined. It was found that while Culex q. poses health threats as a vector of WNV, Aedes aegypti is over three times more abundant in Brazos County. Thus, our research serves to reduce the risk associated with Culex q. and allows for future areas of surveillance that focus on a more widespread species in College Station and surrounding regions
An Analysis of Household Products as Ant Repellents
No full textIn the summer, harvester ants are responsible for all the ant mounds found across the front and back yard of every household across the country. Pogonomyrmex barbatus are extremely active ants and bites when they feels threaten. The sting from the bite spreads poison along our lymph channels causing irritation and can lead to serious medical complications. However, this does not compare to what danger the chemicals in current ant repellents present to our health. Therefore, we tested the effectiveness of household products as an alternative method as ant repellents. A quarter size of honey was deposited into the center of 7 separate plastic containers. Next, for each container we placed one of the following household products: baking soda, black pepper, vinegar, mustard, coffee grounds, bleach, and crushed up bay leaves completely around the honey as a barrier. Then 10 harvester ants are placed on the outside of the barrier to examine which household product kept the most ants away from the honey after 5 hours. The results presented that coffee grounds was the best repellent, because it successfully kept all the ants away from the honey. However, the bleach, vinegar, and mustard were better ant pesticides killing most to all. Therefore, common household substances can be used as an alternative to effectively repel insects or as pesticides. This would reduce the use of harmful chemicals that are found in ant repellent products
Evaluation of Horse Coat Color in Regards to Tick Preference
No full textTicks are a major ectoparasite known to vector a large variety of diseases to both humans and animals. Most tick species have a host species preference, however it is unsure if they have a color preference within that species. For this experiment, the prevalence of ticks on horses with specific coat colors in College Station was recorded in order to determine if certain tick species have a particular coat preference. During two days in mid-fall, ticks were collected from 15 horses of varying coat colors, such as chestnut, bay, paint, grey, black, and blue roan. Of the ticks collected, 77% were found on chestnut horse, 15% on the paints, and 8% on the grey-coated horses. No ticks were collected from the bay, black, or blue roan horses. All of the ticks collected were from the genus Ixodes sp., which could suggest that ticks from the genus Ixodes sp. have a coat preference towards chestnut horses. However, there was not a significant difference (p>0.05) between the number of ticks found on the various colors of horses, so the coat preference color could not be confirmed. Further experiments, such as testing the prevalence of ticks on different age groups in chestnut horses or other individual color groups, could potentially provide insight on what factors make certain horses more susceptible to ticks than others, and would allow improved care of those susceptible horses
Larval Competition Between Aedes and Culex sp. (Diptera: Culicidae) found in Texas on Artificial Diets
No full textMosquitoes (Diptera: Culicidae) are notorious vectors of diseases that pose serious threats to human health, making them highly relevant topics of study within many research laboratories. Studies to further understand mosquito biology and ecology are vital to develop more cohesive epidemiological models and effective methods of vector control, making the need for a fuller understanding of interspecies larval competition and its effect on mosquito fitness particularly important. In this experiment, the ability of resource procurement of Aedes aegypti and Culex quinquefasciatus larvae was tested against interspecies competition in a laboratory setting in an attempt to determine which species would show an increased fecundity specifically in a lab setting. Eggs of each species were reared till adulthood and their numbers of emergence were recorded in order to observe the effects of interspecies competition in the larval stage on fitness. Results collected concerning larval mortality showed no obvious advantage for either species, showing similar rates of survival despite competition for food resources. These results suggest that the two species are relatively equally matched at the larval stage, but further refined experiments and analysis are required to ascertain the full effects of competition between these species
The Attractiveness of Commercial Baits Toward Red Imported Fire Ants Solenopsis invicta (Hymenoptera: Formicidae)
No full textFrom causing painful stings on animals and humans alike to damaging land, the Solenopsis invicta, or Red Imported Fire Ant, is an economic burden to the United States. Insecticidal baits are often used to control these pests, each containing their own proprietary coating. Discovering which formulation of bait is most attractive to fire ants would help inform consumers to select the proper bait for their personal fire ant control. After baiting ants following the method laid out in Kaspari et al. 2008 with six different baits, it was discovered that the most attractive bait attracting the largest percentage of ants was Advion with its lipid blend. Advion was significantly more attractive than the negative control of honey. However, the Advance 375 A protein blend was also significantly more attractive than honey. The success of the Advion bait in attracting a larger percentage of fire ants over the Advance 375 A bait may be due to seasonal timing as this experiment was done in early April. Fire ants may currently be choosing nutrition with a high content of stored energy. More research should be done to see if as fire ants prepare to reproduce in later spring, they may change their foraging bait preference to Advance 375 A’s protein blend in order to support their colony’s larval development with additional protein
Effectiveness of Hemp Oil and Orange Citric Oil as Fire Ant (Solenopsis geminata) Repellent
No full textMore and more people are looking for solutions to their pest problems outside of the mainstream pesticides and pest repellents found in stores and are turning toward “home-remedies” such as essential oils. However, there is limited research about the effectiveness of certain essential oils on repelling and killing arthropods. This experiment covered the use of hemp oil and orange citric oil as possible repellants for fire ants (Solenopsis geminate) common to the Brazos Valley of Texas. Collection of ants was done from an ant mound next to the Texas A&M entomological building and running of the experiment was done inside the building. Petri dishes were used to contain the experiment and the number of times the ants touched the substance was counted and compared against the others. The water control had the height touch count and its average was statistically different (p value= 0.00028805) than the substances tested. Orange citric oil had consistent results among its three trials and there was a statistical difference between it and the control tests. Hemp oil was not as consistent in its results. Although two of the trials had counts very close to each other, the third trial had more than double the counts than the other trials. These results show that orange citric oil was a very effective repellant to Solenopsis geminata compared to the water control. Hemp oil shows promise as a repellent but a larger experiment size would need to be used in order to determine the consistency of its effectiveness. Possible next steps in this line of research include expanding on hemp oil’s effectiveness, determining if the ability of an oil to aerosolize changes its effectiveness, and if other essential oils are effective as repellents against Solenopsis geminate
Comparison of Solenopsis invicta (Hymenoptera: Formicidae) Attraction to Different Common Household Products
No full textThe purpose of this experiment was to study the attraction habits of S .invicta to common household products in College Station, Texas. S. invicta is a nuisance to the agricultural industry as they cause damage to equipment and lower crop yields. Various common household products ranging from dental hygiene to food products were used in the study. Products that exhibited the most attractive properties included foods with high sugar content. Among the household products with the lowest attractive properties were acidic substances such as tapatio hot sauce, listerine, and 40% ethanol spirit (vodka). Basic substances such as hand soap also exhibited poor attractive properties
Forensics Meet the Imagination of the Blind: Getting Positive Media Attention on "Can the Blind Solve the Crime?" Is there substantial evidence in imagination?
No full textClose your eyes and try to remember where you placed your keys. Did you hear that? Sto. I believe the sound is coming from the opposite direction. In the imagination world these sensory techniques are crucial. But can they be used to help solve crimes
Effect of Sunlight Versus Shade on the Magnitude of Presence of Forensically Important Species of Diptera in Northeastern Trinidad.
No full textVarious environmental factors can affect the duration of dipteran life cycles, a cycle important in forensic entomology when determining the time of colonization, which could be a time of death estimate. The amount of sunlight a carrion receives can influence the magnitude of presence of Diptera. In order to investigate, FTD2 disposable fly traps were used in lieu of carrion and were placed in direct sunlight and under shade for a total of 5 days between approximately 0700 and 1730. Diptera were collected and counted daily. Monitors of Ambient Light Intensity (MALI) sensors were used to determine the amount of sunlight a trap received by counting pulses of light outside a preset lux meter minimum or maximum. Shaded traps collected higher numbers of flies as time progressed while traps placed in direct sunlight collected fewer. A Fisher Exact test was used, and it was determined that there was a statistically significant trend that the flies preferred the shaded traps over the sunlit. Further trials and emphasis on ultraviolet radiation could be beneficial in determining a more statistically significant trend
A Study Comparing Essential Oils as Repellents and Pesticides Against the Red Imported Fire Ant, Solenopsis invicta
No full textSolenopsis invicta, the Red Imported Fire Ant, is an invasive species that poses a threat to certain individuals by entering homes and living spaces. However, pesticides are overused and finding other more natural methods of repelling and killing these insects is necessary. In this experiment, the essential oils lemongrass, lavender, and tea tree oil were tested to determine their efficacy as repellents and insecticides against these ants. To test them as repellants, the ants were placed inside of a square, plastic container close to the wall opposite of the bait. There was a line of oil with a space left for the ants to walk through to access the bait. Tea tree oil proved to be the best repellant, deterring the ants from accessing the Oreo bait one-hundred percent of the time. To test these oils as insecticides, the ants are placed in small drops of each oil and left until they were deceased. Lavender was shown to be the most effective insecticide, but the results of this portion were deemed inconclusive. The results of this experiment were important in demonstrating that using natural insect repellants is possible to decrease the amount of chemical pesticides used globally.