Instars: A Journal of Undergraduate Research (Texas Digital Library - TDL E-Journals)
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A Survey of Acari Species and the found Prevalence of Medically Relevant Ixodes sp. in College Station, Texas
No full textWithin the Acari species, there are a number of specimens known to spread diseases of medical importance. Of the two most common tick spread diseases found in Texas, Lyme disease and Rocky Mountain Spotted Fever, Lyme disease, caused by Borrelia burgdorferi, has a higher number of incidents and therefore is the focus of the survey. This disease is known to have detrimental effects on the nervous system and heart in humans. Two species are known for being prominent vectors of Lyme disease, Ixodes scapularis, and Ixodes pacificus. Of these two ticks, I. scapularis is a common tick found in Texas and is the primary tick to identify. A survey of ticks obtained from local animal shelters was performed and 29 species were identified. I. scapularis had the highest rate of identification. Due to the high amounts of I. scapularis in the survey, actions can be taken by the community to prevent future outbreaks of Lyme Disease in the College Station and Bryan areas.
Keywords: Ticks, Lyme disease, Ixodes scapularis, disease, vector, surve
A Comparative Study on the Escape Behaviors of Orthopterans in San Juan de Peñas Blancas, San Ramón, Costa Rica
No full textA total of three trials were conducted to compare the escape behaviors of the various Orthopterans Abracris flavolineata (De Geer, 1773), Orophus sp. (Saussure, 1861), Silvitettix sp., Leptomerinthoprora brevipennis (Rehn, 1905). Since many Orthopterans use visual stimuli and react in similar ways to threats, the selected trials tested different kinds of escape behaviors. The first trial testing an approaching vertical stimulus showed no significance in escape behavior between A. flavolineata and Orophus sp. Trial two with a horizontal stimulus also showed no significance, this time between all four species. When looking at solely the grasshopper species in a contingency test from trial two, there was indication that they behaved similarly. Trial three was held outdoors with an approaching downwards angled stimulus, also showing no significance between the four species. When comparing the indoor trials to the outdoor trials, the results were significant, indicative that the specimens reacted faster indoors. A large factor in the results showing insignificance can be traced to the lack of enough specimens to test
Fluorescent Patterns Found in Common Arthropods With Exposure to UV Light
No full textFluorescence occurs in arthropods due to the absorption of electromagnetic radiation from UV light rays. Many species of arthropods exhibit this trait as a result of unique pigments within their cuticle layers. This trait is useful for certain arthropods because it can aid in sexual selection and help them recognize other organisms of the same species. In this experiment, twenty different common arthropods were photographed under normal lighting and under UV light in order to determine if they exhibit fluorescence. Each specimen was then compared to the normal image under standard lighting in order to determine the amount of fluorescence. Many of the arthropods photographed demonstrated slight amounts of fluorescence on certain body regions. The majority of fluorescence was concentrated on the softer cuticle inside the sutures on their body segments. The differing amounts of fluorescence exhibited by each arthropod may help to reveal the different evolutionary pressures their ancestors faced. The majority of the sample displayed only a slight fluorescence, which may indicate that high amounts of fluorescence are not evolutionarily favored. 
Diurnal Activity of Gravid Aedes aegypti (Linnaeus) (Diptera: Culicidae) in Toco, Trinidad
No full textAbstract: Mosquitoes pose a threat to human health due to a variety of arboviral diseases that they are able to transmit. Many of these diseases are vectored by Aedes aegypti and most are prevalent in many parts of South America and The Caribbean. Gravidity, diurnal activity, and the reproductive capabilities of Aedes aegypti are important to research because future generations of mosquitoes can be studied or eliminated in hopes of reducing future outbreaks of disease. New findings would help researchers obtain new ways of preventing future cases of disease, and would reduce the impact that this health-endangering mosquito has on local communities. A survey of the Jammev Beach Resort in Toco, Trinidad was conducted to determine what time of day had the highest concentration of gravid Aedes aegypti. In order to catch the mosquitoes, diaphoretic clothing was left in an open area. This clothing was used to lure the mosquitoes to the preselected location and sticky cards were used to efficiently catch the mosquitoes. This sweat-baiting method could be replicated and applied to future research in order to test its full potential. Results showed that gravid Aedes aegypti were found in higher concentrations at dawn and at high noon. It was also concluded that both gravidity and mosquito presence decreased as the day progressed. Lengthier studies with more effective trapping methods should be conducted during the wet season to fully understand the activity and reproductive capabilities of Aedes aegypti.
Evaluation of growth performance of Tenebrio molitor (Coleoptera: Tenebrionidae) larvae in the presence of supplemental organic material
No full textYellow mealworms, or the larval form of Tenebrio molitor, is a promising new source of alternative animal proteins for the food industry. These larvae can be raised on agricultural by-products and supplemental organic material such as fruits and vegetables. The objective of this experiment is to evaluate the growth rate of yellow mealworms when provided with an ad libitum supplemental diet of different fruits and vegetables in conjunction with a substrate of 50% brewer’s yeast in wheat bran. While no statistically significant correlation between weight gain, larval survival rate, and organic supplemental material was found, it was determined that a higher nutritional composition of organic supplements in regard to carbohydrates resulted in a higher weight gain, and the moisture levels of the organic materials provided contributed to larval deaths during the experiment
Determining Defense Priming of Squash Plants (Curcubitaceae: Cucurbitales) Against Salt Marsh Moth (Lepidoptera: Erebidae)
No full textIn response to being fed on by herbivores, plants produce volatile compounds that play important roles in plant defense. A relatively recent discovery revealed that undamaged neighboring plants can detect these volatiles as a warning of possible future herbivore attack and respond by priming their anti-herbivory defenses. Primed plants typically mount a faster or stronger defense after an herbivore begins feeding. Plant volatile-mediated priming has been observed in many plant species but has not yet been documented in the family Cucurbitaceae. Therefore, we sought to test if squash plants (Cucurbita pepo) respond to volatiles from herbivore-damaged plants by priming their defenses. Our objective was to evaluate plant priming in response to herbivory. For our objective, emitter plants were either damaged by specialist salt marsh moth caterpillars (Estigmene acrea) or left as undamaged controls. Neighboring “receiver” plants were exposed to damage or control emitter volatiles for 24 hours and then challenged with herbivory by larvae. We quantified the amount of herbivory on receivers and found a difference in damage between volatile exposed receivers and unexposed receivers. As well as a significant presence of salicylic acid in the exposed receivers before infection. Taken together, our findings contribute to a better understanding of plant defense priming and offer insight into how plants predict and defend against different herbivore specie
Effectiveness of Ant Baits and Their Relationship with the Species of Ants Attracted
No full textInsect infestations caused by a single species require control techniques that take advantage of the target’s natural instincts and passively lure them out of hiding. Bait traps commonly mimic the odor of food with chemical substitutes that trick an insect’s senses to passively guide it to the trap. The purpose of this experiment was to test Texas ant species preferences for a carbohydrate or protein food source. Furthermore, comparisons were made of the data collected from different environments to test for preference differences between isolated populations of the same species. Data collection required three sticky traps; an unchanged control lacking a source of bait, and two others containing either a carbohydrate or protein-rich food source. Placing the traps in varying habitats allowed the testing for an environmental influence on a particular species’ food preference. The results suggest that, among the ant species collected, a majority prefer a carbohydrate food source. While the numbers favor carbohydrates, the specimen collected from the protein and control traps demonstrates an ability to utilize multiple food sources to attract a species and that food attractants improve the success of trapping. This experiment supports the benefit of bait trapping with carbohydrate attractant in ant pest management plans, but also shows that a combination of protein and carbohydrate attractant serves best
Common Household Reagents that React with Luminol in a Similar Manner as Hemoglobin that Decrease the Reliability of Luminol
No full textAbstract: This study was conducted to identify common household reagents, such as bleach or rust, that would react with Luminol in a similar manner as hemoglobin, and thus decrease the reliability of Luminol when used at crime scenes. This experiment was conducted in a household, using 10 samples of the household reagents bleach, rust from pennies, laundry detergent, hoisin sauce, lemon juice, and urine. A small sample of blood in addition to each of the 10 samples of the reagents were placed onto a bed sheet, and liquid Luminol was sprayed over them. The luminescence, or lack thereof, of the Luminol in conjunction with each of the household reagents was then ranked on a scale of 1-4 in terms of how similarly it appeared to that of the hemoglobin. The major findings from this study, were that the bleach reacted with Luminol 95% of the time. Rust on pennies reacted with Luminol 70% of the time, whereas hoisin sauce reacted with Luminol only 17.5% of the time. Urine reacted with Luminol minimally and 7.5% of the time, and lemon juice and laundry detergent reacted with Luminol 0% of the time. Bleach and rust (Copper Oxide) were determined to have a high chance of decreasing the reliability of Luminol. Hoisin sauce, urine, lemon juice, and laundry detergents are common household reagents that do not have much bearing on the reliability of Luminol when it is used at crime scenes
Observing the Meal Preference of Flies (Dipterans) With Strawberries, Spinach, and Ground Beef
No full textThis experiment tests the meal preferences of flies (Dipterans) in the nearby surroundings with fresh and rotten strawberries (Fragaria x ananassa), spinach (Spinacia oleracea), and ground beef. Each variable was placed onto a plate behind Clements Residence Hall at Texas A&M University and observed for an hour to obtain a sizable amount of data. A total of six sets of trials were run and analyzed through scatter plots and trendlines. The number of flies per variable was averaged and compared to one another. Rotten ground beef, ground beef, and rotten strawberries had the highest fly averages. Rotten ground beef, of the six total variables tested, was shown to be the favored meal of flies. However, the results were biased, as the trials for the strawberries were done under significantly colder conditions than that of the ground beef and spinach. It was determined that the experiment needed modifications to ensure proper analysis and to prevent bias. These modifications consist of varying the rotting period of each trial and ensuring that each trial was conducted under similar temperatures. Ideally, above 20 degrees Celsius. This would allow for all observations to be as unbiased as possible while providing more data to analyze and compare, resulting in a very decisive conclusion with little to no error
Comparison of Culicidae Present in Phytotelmata versus Stream Pools at Springfield Station in Dominica, West Indies
No full textMosquito borne diseases are proliferating all around the world. Mosquito habitats can be categorized into temporary and standing pools, both of which influence human health. To understand the extent of their presence in Dominica, a survey of mosquitoes was conducted by observing phytotelmata (plant-held water) and pools in streams present at the Archbold Tropical Research and Education Center (ATREC) in Dominica, West Indies from May 23rd, 2017 to June 14th, 2017. To test phytotelmata and pool stream habitats, samples were collected from different water holding plants and standing pools in various areas surrounding the station. The larvae obtained from these samples were then reared and identified. Fifteen mosquitoes were reared from pool streams, and 27 mosquitoes were reared from phytotelmata. The species Aedes busckii (Diptera: Culicidae) (Coquillet) were found to be the most common in phytotelmata, and Culex quinquefasciatus (Diptera: Culicidae) (Say) were found to be the most common in pool streams. Past research suggested that Aedes busckii were the only species found in phytotelmata. However, Culex inflictus (Diptera: Culicidae) (Theobald) was also found to inhabit water-holding plants.