Instars: A Journal of Undergraduate Research (Texas Digital Library - TDL E-Journals)
Not a member yet
220 research outputs found
Sort by
Effects of Agitation on Hatch Rate of Lucilia cuprina Eggs (Diptera: Calliphoridae)
No full textBlow flies are important for their use in Maggot Debridement Therapy (MDT) to treat patients’ wounds. Many different sterilization techniques are used on their eggs in a process to reduce the transfer of bacteria from the maggots to the patients. Agitation can be used in an attempt to disrupt the biofilm of bacteria found on an egg’s surface. In this study, Lucilia cuprina eggs were collected and the effects of agitation on hatch rates was tested. After collection, eggs were put on filters, covered in an insect saline solution and put through two treatments: (1) a control with no agitation soaking in saline for five minutes and (2) an agitation treatment at 5 rpm soaking in saline for five minutes. Afterwards they were rinsed with leftover saline and plated in nutrient agar cups to observe the hatching process. Agitated eggs had significantly lower hatch rates than the non-agitated control treatment. These data showed that agitation had an adverse effect on mortality of the fly eggs, but provided no information on the effect on bacterial life. The importance of this study cannot be fully understood without knowing how agitation affects the bacteria found on the tested fly eggs
A Survey of Odontomachus (Hymenoptera: Formicidae) and General Observations of Nesting Preferences in the Commonwealth of Dominica in the West Indies
No full textOdontomachus spp. were collected from various locations across the Commonwealth of Dominicain the West Indies. Specimens were collected in nest series and information about their location, elevation, nesting substrate, and co-habitation with termitidae and other formicidae were recorded. Many colonies were found to be co-habitating in terrestrial termite mounds or rotting wood along with their termitidae inhabitants. No Odontomachus sp were found in elevations higher than 1686 ft above sea level. High resolution images of each species collected were recorded. Two species were found, most prominently Odontomachus bauri (Emery), and additionally in a single sample, Odontomachusruginodis (Smith). The specimens of O. ruginodis that were collected are new records for the Commonwealth of Dominica.
Effect of Different Bullet Calibers and Distances from Target on Blood Spatter
No full textThis study was carried out in order to determine how different bullet calibers shot from different distances would affect blood spatter. Using two distinct firearms and varying distances, bullets were shot at a target in order to make blood spatter from different angles onto a tri-fold project board. The results illustrated that as the caliber of a bullet and the distance away from a target increase the area of blood spatter will increase and higher caliber bullets create more spatter because of their increased force.
Evaluating the effects of temperature on larval Calliphora vomitoria (Diptera: Calliphoridae) consumption
No full textThe blow flies (Diptera: Calliphoridae) are responsible for more cases of myiasis than any other arthropods. Several species, including Cochliomyia hominivorax and Cocholiomya macellaria, parasitize living organisms by feeding on healthy tissues. Medical professionals have taken advantage of myiatic flies, Lucillia sericata, through debridement or maggot therapy in patients with necrotic tissue. This experiment analyzes how temperature influences blue bottle fly, Calliphora vomitoria. consumption of beef liver. After rearing an egg mass into first larval instars, ten maggots each were placed into four containers. One container was exposed to a range of temperatures between 18°C and 25°C at varying intervals. The remaining three containers were placed into homemade incubators at constant temperatures: 21°C, 27°C and 33°C. Beef liver was placed into each container and weighed after each group pupation. The mass of liver consumed and the time until pupation was recorded. Three trials revealed as temperature increased, the average rate of consumption per larva also increased. The larval group maintained at 33°C had the highest consumption with the shortest feeding duration, while the group at 21°C had lower liver consumption in the longest feeding period. The research in this experiment was conducted to understand the optimal temperature at which larval consumption is maximized whether in clinical instances for debridement or in myiasis cases
Fall 2016 Mosquito Survey of the Greater Bryan/College Station, Texas Area
No full textMuch is known about the numerous species of mosquito and the diseases that they can transmit when the conditions for the host and pathogen are appropriate. Knowledge of the types of mosquitoes that inhabit a particular region can give entomologists and medical professionals an understanding of the kinds of arboviruses that could potentially plague that area. In this study, mosquito larvae were collected from a number of rural and urban sites within and surrounding the area of Bryan/College Station, Texas. Collections were taken from temporary and permanent bodies of water to increase the odds of catching a variety of species. The larvae were then reared to adulthood and identified in the lab. 101 mosquitoes were collected over the course of the study. All of the mosquitos belonged to either the Culex or Aedes genera, most notably Culex quinquefasciatus and Aedes albopictus. The ratio of males to females was nearly even, though females are the primary concern regarding the transmittance of disease. Based on the species collected, it can be determined that the Bryan/College Station area could at some point experience an outbreak of diseases such as West Nile virus or Zika virus, both transmitted by Culex quinquefasciatus, or the numerous other diseases vectored by Aedes albopictus including dengue and chikungunya. Cases of some of these diseases a have already been recorded in Texas, so local officials should be aware of the potential of an outbreak
Comparison of Mosquito Population Between Urban Area of College Station, TX and Rural Area of Snook,TX
No full textIn order to determine where to better allocate resources and pest management, we compared the mosquito population between urban and rural areas. We sampled adult mosquitoes and larvae in College Station and Snook as our representative populations. Our methods included a mosquito trap built from PVC and fine mesh for the adult mosquitoes, and a dipper to sample the larval population. Our results showed inconclusive data for the adults due to malfunction of the mosquito trap. The data for the larvae showed a higher density in urban populations however, this data maybe be deceiving due to the timing of the collection of larvae in the rural area. The rural population makeup was dominated by the Psorophora (Fabricius) (Diptera: Culicidae) species. On the other hand the urban population makeup consisted of Aedes vexans (Meigen) (Diptera: Culicidae) and Culex quinquefasciatus (Say) (Diptera: Culicidae). We believe that the Psorophora eliminated the other competition due to its carnivorous nature and is the reason for the lack of variation of species in the rural population. In regards to population density comparison, our results proved to be inconclusive due to factors unaccounted for. Although, we believe our data regarding population makeup is accurate and the data can be used to analyze the effectiveness of the integrated vector manage of the College Station area nearing the winter months
Effect of Water Submersion on Cochliomyia macellaria (Diptera: Calliphoridae) Eggs
No full textCochliomyia macellaria is a significant species in forensic entomology when accurately determining time of death by using postmortem interval. The larvae participate in secondary myiasis when feeding on the decaying tissue of deceased organisms. Variables such as temperature and location can either speed up or slow down the development of C. macellaria, which need to be taken into account when determining an accurate time of death. Eggs of C. macellaria were collected, submerged in water for varying amounts of time, and observed in order to see if exposure to water caused them to die before hatching. It was found that eggs soaked for one minute had the highest percentage survive. Eggs soaked for zero, two, and five minutes had slightly less survive, while eggs soaked for seven and ten minutes saw a significant decrease in survival. These results will not only assist forensic entomologists when determining time of death, but will also give a better understanding about which habitats this species is most likely to be found in
Investigating Native and Invasive Ant Communities in College Station, Texas
No full textThe purpose of this study was to examine the diversity of ant species and determine the prevalence of invasive and native ant species in College Station, Texas. Different types of bait were placed in various urban landscapes at regular time intervals for five weeks. Of the six ant species collected, the Red Imported Fire Ant (Solenopsis invicta) was the most common species in all areas except the residence halls. This is most likely because inhabited areas are frequently treated with insecticides to control fire ant populations. Lastly, areas with the highest amount of human activity exhibited the lowest species diversity as a result of the negative effects of urbanization. Among the two invasive ant species collected, the tawny crazy ant (Nylanderia fulva) was detected, which represents the first documented case of this invasive ant in Brazos County
Survey of Mosquito Species Inhabiting Bryan & College Station, Texas
No full textMosquitoes are members of the order Diptera and the family Culicidae. They have long been known as pesterous insects; however, their role as vectors has proven an even bigger nuisance to the human race. Mosquito-borne diseases are a serious threat to the health and well-being of all human beings. The recent emergence of serious diseases such as West Nile virus, yellow fever, malaria, and Zika virus have reinforced the importance of studying mosquitoes and their distribution across environments. Researchers have spent much time and money investigating the distribution of mosquitoes worldwide. While it is commonly understood that certain species are more prevalent in particular areas of the world, the distribution of mosquitoes within smaller communities of the United States, such as Bryan/College Station (BCS), is less studied and understood. The purpose of this survey was to gain a greater understanding of how environmental factors influence the prevalence and type of mosquitoes present in the Bryan/College Station vicinity. Mosquito larvae were collected from four different locations once a month from September to November, 2016. The larvae were identified using a wet mount slide. Additionally, some larvae were allowed to develop into mature adults, subsequently killed, and analyzed for identification. Environmental conditions were noted at each collection. Mosquitoes from the genera Aedes, Psorophora, and Culex were identified with Aedes being the most prevalent. Analysis of environmental conditions showed pH had a negligible effect on larval development while water and air temperature did indeed impact larvae numbers. Furthermore, mosquito numbers were greater in populated, brushy areas with standing water.
Measuring the Efficiency of Common Household Products as Repellents for Solenopsis invicta
No full textRed imported fire ants, Solenopsis invicta, are known to be household pests and a potential danger to small children and animals. Fire ants are particularly a problem in the state of Texas because of the $1.2 billion cost in damages associated with fire ant activity. Wildlife, agricultural, and urban areas are prone to fire ant infestation, and the fire ants can cause several problems to plants and animals in that area. The purpose of our study was to find effective, common household products that can function as a repellent of the insect. Using baby powder, cinnamon, and petroleum jelly as individual barriers between the fire ants and honeydew melon, it was found that petroleum jelly and baby powder were the best repellents. Lastly, the cinnamon powder, while effective, was the worst of the three repellents tested. In the future, other common household items should be tested for their efficacy at repelling Solenopsis invicta, but based on our results, it has been found that both petroleum jelly and baby powder are effective repellents of red imported fire ants