Instars: A Journal of Undergraduate Research (Texas Digital Library - TDL E-Journals)
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Differences in Longevity of Chrysomya rufifacies (Diptera: Calliphoridae) (Macquart) and Cochliomyia macellaria (Diptera: Calliphoridae) (Fabricus) Adults
No full textThere are certain morphological features and individual characteristics that are special to varying species that affect their lifecycle through every phase. Certainly, not every species will live for the same amount of time from emergence to death. In our case, there are two species of interest for our experiment. These two species are Chrysomya rufifacies (Hairy Maggot Blow Fly) and Cochliomyia macellaria (Secondary Screwworm). Both fly species have a detrimental impact on the livestock industry. They enjoy feeding on dead tissue after a sustained injury and are the cause of myiasis presence in several livestock species. For this reason, and many more, they are a concern economically. Through general observations, we have noticed that adult Chrysomya rufifacies appear to be much bigger than Cochliomyia macellaria adults are, and wondered if this meant there would be a distinction in longevity of adult life and if the variation in size is indicative of adulthood longevity. Wild maggots were obtained and raised on food-grade bovine liver. The adults were given a sugar water mixture daily until death, in which the number of days lived by each adult was recorded. The data was analyzed using a T-test in SPSS. Analyzing the data this way allowed us to obtain and compare measurements of mean, standard deviation, standard error, and the P value. Our results indicate that Cochliomyia macellaria (p=.0467) adults live much longer than Chrysomya rufifacies adults do, and that size is not indicative of longer life. Further research is needed to evaluate varying results for these two species, as well as conduct new experiments with other forensically important insect species
Stridulation Frequency Dependence on Music Genre in Acheta domesticus
No full textCrickets are mainly nocturnal species known for the loud, persistent, chirping sounds many of their species make. Cricket chirping (stridulation) is produced by stridulatory organs located on their forewings. Stridulation is done by males to entice females, but at times can lure doom, drawing predators and parasites towards them. Consequently, crickets cease chirping when they sense sound frequency vibrations nearby, indicating that a predator is nearby. In this experiment, the cricket species Acheta domesticus, of the order Orthoptera and the family Formicidae, was used to test stridulation frequency differences based on exposure to different music genres. Crickets were exposed to either silence (control), hip hop, jazz, country, or classical music. During this music exposure period, the number of chirps was counted for a minute. Stridulation frequency was 83.3 chirps per minute for the control setting, 65 chirps per minute for classical music, 61.3 chirps per minute for country music, 54 chirps per minute for jazz music, and 41 chirps per minute for hip hop music. Causative factors for this trend may be due to neurological characteristics of the cricket. A major auditory sensory neuron, Ascending Neuron 1 (AN1), is excited by both high-frequency sounds and self-generated chirps. We conclude that music genres dominated by high-frequency sounds, such as hip hop and jazz, stimulate AN1, causing increased auditory information to be sent to the brain, leading to decreased stridulation as crickets interpret this information as the presence of a possible threat
Survey of Ant Genera and Biodiversity in Toco
No full textTropical regions are widely known for their high species diversity, which is often threatened by the growth and encroachment of human activity into natural areas. The ants of Trinidad have been studied, but most surveys and records are restricted to the Port of Spain area on the northeastern coast. This study is focused on the ant biodiversity in northeastern Trinidad, a region approximately 87 km from Port of Spain. Over the course of seven days, ants were surveyed on the Jammev Beach Resort property (Toco) using baited ground pitfall traps, baited arboreal pitfall traps, and from freely collected specimen. A total of 298 specimens were collected, representing 12 genera and tribes of Formicidae. The most prevalent ants were Tertamorium sp with 105 specimens and unidentifiable Formicinae with 88 specimens. A Shannon Diversity Index of 1.925 was obtained, indicating an average amount of diversity
The Effects of Black Objects and Carbon Dioxide on Horse and Deer Fly (Diptera: Tabanidae) Trap Success in Brazos County, Texas
No full textThis study analyzed the effectiveness of traps for horse and deer flies (Diptera: Tabanidae) in Brazos County, Texas, U.S.A., using black objects and carbon dioxide (CO2). Tabanid flies vector several important livestock diseases and can be pests to humans. Heliothis cone traps were modified and placed at four approximate locations on one site, the Riley Estate in Brazos County, Texas. Four different trap styles were randomly tested at the locations on eight days between 24 March and 14 April 2015. Seventeen individual tabanids representing two species, Chrysops callidus Osten Sacken and Tabanus lineola F., were collected and the former species was the most abundant. A one-way analysis of variance (ANOVA) calculation revealed that the combined black object and CO2 trap had a positive trend for being the most effective style for capturing tabanid flies out of those tested. Trap location was determined to be insignificant compared to the number of tabanid flies captured. While more data is required to determine if the difference between the trap styles is significant, the traps have the potential to be used to collect behavioral data, measure biodiversity and relative abundance of tabanid flies, as well as control their populations in areas where they cause irritation and spread disease
Bacterial Flora Found in Common Indoor Insects
No full textAbstract The most common indoor arthropods that are considered pests include cockroaches, flies, and ants. They are often associated with unsanitary conditions because they thrive in environments with high organic content such as sewage, garbage, and other decomposing material. Although these insects are very capable of hosting and transmitting bacteria, entomologists and medical professionals rarely consider them to be of medical significance. As a result, an experiment was conducted in which sticky traps were utilized to collect specimen within various buildings on Texas A&M University’s campus. The collected specimens included cockroaches, house flies, fire ants, and a cricket. The specimens were then swabbed on agar plates and the plates were left for 72 hours to allow for microbial growth. In addition, different segments of the captured specimens were swabbed to determine which area of the exoskeleton contained the highest concentration of bacteria. The results indicated that all the specimens had microbial growth on their plates. However, the cockroach, Periplaneta fuliginosa, and cricket, Acheta domesticus, had the most bacterial growth out of all the specimen. In both Periplaneta fuliginosa and Acheta domesticus, the wings were the areas that showed the most microbial growth. The presence of microbes indicates that these specimens do have the potential to have medical importance because they are found in indoor environments where human activity is prevalent. The fact that most of the growth developed from their wings indicates that they could easily spread pathogens during flight by releasing it into the air
Evaluation of Beer Preference in American Cockroaches Periplaneta americana (Linnaeus) (Blattodea: Blattidae)
No full textCockroaches (Blattodea) are common worldwide pests that can have a negative effect on public health by transmitting pathogenic bacteria to humans and contributing to asthma problems. Cockroaches have developed a growing rate of behavioral resistance, and resistance to chemical insecticides, so it has become more important to use less toxic methods of population control in order to mitigate the development of resistance. One such method of control is to use beer-soaked bread as a bait for cockroach traps. Four different bait mixtures were made from the combination of bread with DI water, 25% sugar water, a non-hoppy beer, or a very hoppy beer. The number of cockroach visits to each bait was recorded and data were analyzed to determine any sort of preference the American cockroach, Periplaneta americana (Linnaeus) (Blattodea: Blattidae) may have for the two different beers. Overall, the cockroaches most preferred the sugar water bait, however, data suggests that there was still a significant (p=0.022251) difference in preference for the non-hoppy beer over the very hoppy beer. This data could potentially improve the efficacy of using beer as a cockroach bait, but further studies are required in order to support this conclusion with other species of cockroach
Assessing Effects of Ant-Aphid Mutualisms on Grain Sorghum Health
No full textInvasive insect pests are known to cause yield loss and economic damage to grain sorghum crops (Sorghum bicolor). This damage can be exacerbated by invasive insect mutualisms, or beneficial interactions. For example, tawny crazy ants (Nylanderia fulva) (Hymenoptera:Formicidae) (TCA)tend sugarcane aphids (Melanaphis sacchari) (Hemiptera:Aphididae) (SCA) for the honeydew or sugary excretion that they produce from feeding on the plant. This tending can reduce plant nutrients, which decreases plant health. Currently, it has not been studied whether the mutualism between TCA and SCA has any effects on grain sorghum health. To access potential plant health effects of this mutualism, potted grain sorghum plants of similar development were evaluated in a greenhouse environment. Plants were evaluated in pairs, with each individual plant having 25 sexually mature SCA and the treatment plants having an addition of 300 TCA workers. Plants were enclosed in individual fine mesh cages and placed inside a Fluon lined bin to prevent the organisms from escaping. Damage was assessed by measuring the dry root weight, change in leaf chlorosis, and change in plant stem diameter after the 14-day experiment. There were no statistically significant differences found in the treatments for dry root weight (P = 0.61), leaf chlorosis (P = 0.37) or stem growth (P = 0.25). Future studies should increase the duration of the experiment to determine potential effects of long-term interactions of TCA and SCA on grain sorghum health. Monitoring and controlling ant-aphid mutualisms may be important for the Integrated Pest Management for this agricultural cro
Relationship Between Where a Spent Shell Casing Lands and the Shooter\u27s Location Based on Type of Gun
No full textOften times, when spent shell casings are found at a crime scene, the location of the shell casing is used to indicate the location of the shooter. The assumption is that semi-automatic rifle shell casings land to the right and in front of the shooter and that semi-automatic handgun shell casings land to the right and behind the shooter. The author of this study investigated if there is a trend between the shooter’s location and the angle and/or distance of a spent shell casing for both a semi-automatic rifle and semi-automatic handgun. Each firearm was fired ninety times, ten trials, each with nine rounds, from the same distance from the target, same surface and same shooting form. The results emphasized a consistency with the assumptions that semi-automatic rifle shell casings land to the right and in front of the shooter and that semi-automatic handgun shell casings land to the right and back of the shooter. The results also draw attention to the fluctuating distances and angles of the spent shell casings. These results demonstrate that determining a shooter’s location solely on the location of spent shell casings can only lead to a cautious location of the shooter
Effectiveness of Hermetia illucens (Diptera: Stratiomyidae) Larvae at Decomposing Household Food Products
No full textEfforts to control and dispose of human food waste typically rely upon increasing public awareness of the problem and improving retail management practices to mitigate the amount of food thrown away. Food waste becomes an increasingly noticeable problem as the world population continues to grow, creating a host of environmental concerns. A recently executed experiment examined the ability of Hermetia illucens (Family Stratiomyidae and Order Diptera) to decompose household food waste. In previous studies, Hermetia illucens (Black Soldier Fly) has shown promising ability to decompose organic food waste. In our experiment, we intervened in the life cycles of Hermetia illucens larvae by feeding them five separate food groups over a two week timespan: grains, vegetables, fruits, meat, and dairy. By comparing the initial start weight of the larvae and the end weight after the larvae consumed their respective food groups, it was determined that Hermetia illucens larvae decompose fruit, meat, and vegetables most effectively. These findings suggest that Hermetia illucens larvae may be a viable alternative to decompose specific food groups in everyday household environments. Keywords: food waste, black soldier fly, Hermetia illucens, decomposition, composting, larva
Examining the Preference of Sodium Concentration in the Diets of Nasutitermes corniger (Blattodea:Termitidae)(Motschulsky)
No full textSodium is an essential element for the nervous system of many animals, including termites. This experiment tested different sodium concentrations on rotting wood blocks and cellulose in a pure, powdered state. Nasutitermes corniger termites were collected from a nearby colony. Thirty-eight colonoids were created, which consisted of 10 soldiers and 50 workers each. Each colonoid was kept in a Petri dish with a damp filter. For the first part of the experiment, Seventy-six blocks of wood were cut into pieces of similar mass and dipped into sodium concentrations ranging from 0-10% for 10 seconds. The blocks were placed 1cm apart on the arenas and the termites were left to roam for a certain amount of time. In the second part of the experiment, sodium concentrations ranging from 2-8% were made by mixing with pure, powdered cellulose. The arenas contained all four concentrations this time. It was observed that N. corniger termites do not have a clear sodium preference, however some trends were apparent in both experiments. Further experimentation would be needed to explore these trends