Instars: A Journal of Undergraduate Research (Texas Digital Library - TDL E-Journals)
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Relative Efficacy of Common Larvicides on Aedes albopictus (Diptera: Culicidae)
No full textThe mosquito species Aedes albopictus (Diptera: Culicidae) is known as a significant threat to human health due to its ability to vector diseases such as Dengue fever, West Nile virus, Chikungunya, yellow fever, and Zika virus. The ability to control the population of Aedes albopictus by applying treatments that terminate the larval stage would greatly reduce the number of these disease vectors, and thereby disease transmission rates, within the area of treatment. An experiment was conducted to test the efficacy of several larvicides in exterminating the mosquito species Aedes albopictus. Specimens were collected in the Bryan/College Station area, and malathion 57%, permethrin 36.8%, Bacillus thuringiensis israelensis, and oil treatments (a positive control group) were analyzed. The effectiveness of each larvicide was measured by the average mortality rate observed across two trials in comparison to the results of a negative control group. The order of successfulness of the pesticides (most to least effective) was concluded to be oil, Bacillus thuringiensis israelensis, permethrin, and malathion. While the samples treated with permethrin and malathion had Aedes albopictus mortality rates ranging from about 40.9% to 56.5% in the two trials, the samples treated with B.t.i. displayed 50% to 61.9% mortality rates in each trials. Oil, the positive control, presented the expected 100% mortality. However, oil is an unrealistic treatment method due to its negative effects on the environment as a whole. Thus, Bacillus thuringiensis israelensis was concluded to be the most effective and applicable larvicide for Aedes albopictus
The Effect of Treated Beef Liver on Blowfly Colonization
No full textCommonly known as the predominant insects responsible for the decomposition of human remains, blowfly larvae are of medical importance to forensic and medical entomologists. In order to perform an entomological survey about the effects on blowfly colonization time and delay composition, the use of treated and untreated beef liver were expended to attract blowflies. On April 14th, 2017 at 11:30am, six mason jars with sand, 3 containing beef liver soaked in vinegar and 3 containing untreated beef liver, were set up 1 meter away from each other in a secluded area of the woods. Protected from stray animals or scavengers, the jars were left undisturbed for five days for specimen collection and then, were extracted, killed, and ready to be identified. Out of the six mason jars, two of the three treated beef liver had higher amounts of blowfly specimens collected compared to treated jars. Based on the obtained results, the hypothesis was proven wrong and the beef liver treated with vinegar actually sped up the colonization of blowflies. However, it was suspected that several variables could have skewed the results such as the weather or placement of the mason jars. We see this through the lack of larvae in one of the treated jars, the variation of beef liver texture, and the location of maggots found within the mason jars. Although some specimens were unidentifiable due to the size of instar maggots, the most prevalent larvae collected was Lucilia coeruleiviridis. Overall, the results of this entomological survey displayed the different species of blowflies in the Bryan/College Station area specifically during the spring semester as well as showcased the effect of treated or untreated meat source on the collection of blowflies
Evaluation of Chemical Treatments against the black carpenter ant (Camponotus pennsylvanicus)
No full textThe Camponotus pennsylvanicus ant plays a beneficial role ecologically because these ants nest in dead wood and aid in its decay. However, Camponotus pennsylvanicus ants are a common pest. They can damage the structure of houses and other infrastructure. Therefore, ensuring pest control is an important issue. Current Camponotus pennsylvanicus control measures include baits, chemical treatments, and preventative sprays (Carney 1969). In this experiment, four commonly used and readily available killing agents were tested, each with a different chemical makeup (Theil and Köhler 2016). The four different killing agents used were dimethyl benzyl ammonium chloride (Hot Shot), imiprothrin (.060%) (Raid), prallethrin (.02%) (No Pest), and water ammonium lauryl sulfate (Ajax/ water). The ant killing agents were tested by collecting the Camponotus pennsylvanicus ant in petri dishes. Eighty specimens were collected and these specimens were separately exposed to the four different ant killing agents during three individual trials. The efficiency of each pesticide was evaluated by comparing total averaged percent of killed ants for each killing agent gathered from the trials conducted. Data collected indicated that dimethyl benzyl ammonium chloride is the most effective pesticide among the chemical treatments used against Camponotus pennsylvanicus
Comparison of Attractant Type, Trap Size and Trap Color based on Number of Diptera Captured at a Livestock Facility
No full textBiting and filth flies are typically present in large numbers at livestock facilities. Using surveillance tools to monitor the species composition and abundance is a critical part of integrated pest management. We evaluated a commercial funnel trap with different sugar bait attractants to evaluate the effectiveness at capturing these flies. We selected the Texas A&M University Sheep Center as the location to perform the study. Two different sugar baits were compared to determine which one was more effective at attracting flies. Another variable that was tested was whether trap size and color affected the number of flies that were captured. The specimens were collected, preserved, and counted, and the data was recorded. Upon analyzing the data, it was established that the two sugar baits were not extremely different in their ability to attract flies. There was however, a noticeable difference in the number of flies captured in the large versus small traps and the small dark versus small light traps. The conclusions made from this study can be used by people who are looking to trap flies in a similar environment to the one tested.
Efficacy of Professional and Homemade Residual Pesticides on Solenopsis invicta (Hymenoptera: Formicidae)
No full textThe invasive red imported fire ant, Solenopsis invicta, has recently gained attention in the United States due to its increased prevalence in urban areas. The species has been linked to aggressive attacks that primarily affect young children and the elderly. Because Solenopsis invicta is an invasive species, it has been able to reproduce without hindrance and has made its way into people’s homes. The purpose of this experiment was to determine the effectiveness of various residual insecticides on individual ants. The insecticides that were studied included commercially available products such as Raid, as well as home remedies like Dawn Dish Soap. The experiment tested the insecticides’ residual effects with five trials each, and each trial had one ant in the testing chamber. The time allotted for each test was an hour, and the chamber was observed at differing time intervals. The results indicate that commercial insecticides kill ants more quickly than most known home remedies, and most of the products tested killed an ant within an hour. The known insecticides tended to kill nearly instantaneously upon contact with the ants, while the home remedies killed over a more sporadic time frame. Lastly, this study concluded that the cost of most products tested were comparable, and that lemongrass insecticides may have a newfound place in fire ant control effort
Comparison of Adult Longevity of Chrysomya rufifacies and Cochliomyia macellaria (Diptera: Calliphoridae)
No full textChrysomya rufifacies (Macquart) and Cochliomyia macellaria (F) are two important insects in the field of forensic entomology. Due to their tendency to immediately colonize a corpse after death, a comparison of sample flies taken off of a corpse and estimates of the duration of different parts of their life cycle is a valuable tool for determining the post-mortem interval (PMI) of a body. In order to accurately determine the PMI, the estimate of the duration of all of the insects’ life stages must be as accurate as possible. Chrysomya rufifacies larvae, in addition to feeding on carrion, are also facultative predators of other insects, including C. macellaria larvae. This predator-prey interaction of these species on a corpse in the wild could affect the development time of one or both species, and one factor that could affect their interactions is the relative adult longevity of each species. Chrysomya rufifacies were observed to have a larger adult body size than C. macellaria, and this study was performed to determine if Ch. rufifacies also has a greater adult longevity than C. macellaria. The flies of both species, born of wild caught specimens, were reared in a laboratory, and the adult lifespans of the flies were measured. It was found that the C. macellaria adults had a mean lifespan of 27.133 days, and the Ch. rufifacies adults had a mean lifespan of 23.426 days, which is a significant difference (p < 0.05)
Comparison of the longevity of Cochliomyia macellaria (Fabricus) and Chrysomya rufifacies (Macquart) adult males (Diptera:Calliphoridae)
No full text Abstract: Depending on the species, males or females tend to exhibit increased longevity based on heterogametic chromosomes. While differences in longevity between males and females of a species has been extensively studied, differences in longevity between males of the same family has been minimally investigated. Longevity is crucial in understanding an insect’s physiology; it can affect developmental times and other life history traits. Cochilomyia macellaria and Chrysomya rufifacies are two Calliphoridae species that are known to cause myiasis, which is detrimental to the livestock industry. By determining the longevity of the adult C. macellaria and Ch. rufifacies males, it is possible to use the data to predetermine future myiasis outbreaks and take preventative action. Wild maggots from both species were reared and emerging male longevity was recorded. Results show that male C. macellaria adults lived an average of 27.79 ± 10.96 days, significantly longer than Ch. rufifacies adult males that lived an average of 21 ± 12.80 days (p=0.021). It is possible that the difference in longevity is due to mating; Ch. rufifacies mate sooner than C. macellaria, due to differences in female developmental time and longevity
Effects of varying concentrations of pure lemon juice and peppermint essential oil on the extermination of Solenopsis invicta (red imported fire ants)
No full textSolenopsis invicta, also known as the red imported fire ants are a common nuisance in the United States. They are known for destroying crops and causing anaphylaxis in people. The experiment was designed to tell whether common household items would be efficient in terminating ants. Ants were collected and separated, and different concentrations of peppermint essential oil and lemon juice were made to test which of the two was the stronger insecticide. The results showed that peppermint essential oil was the better insecticide out of the two presented.
Effectiveness of DEET & Non-DEET Repellents on Culex quinquefasciatus
No full text In this experiment the effectiveness of various mosquito repellents were tested. Mosquitoes are known to be carriers of numerous diseases, making repellents an important means of protection. Because of with the growing “anti-GMO” and “organic” trends this experiment tested the most common chemical repellent as well as “natural” repellents. The tested species of mosquito were in the family Culicidae (Culex quinquefasciatus). The C. quinquefasciatus used were reared in the lab to be test subjects for this feeding experiment. Out of the three repellents, only the one with diethyltoluamide, or DEET, appeared to have any noticeable effect on the feeding of mosquitoes. Non-DEET repellent appeared to have a significantly less effect on the feeding habits of C. quinquefasciatu