Instars: A Journal of Undergraduate Research (Texas Digital Library - TDL E-Journals)
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Nutritional Preferences of Formicidae in Costa Rica
No full textAnt nutrition has been studied across the world and heavily in the United States. The nutritional preferences of Formicidae in tropical environments have little to no research. In order to create the most affective baiting methods for ant colonies, five nutritional treatments were tested among the native ant species of Costa Rica. The transects consisted of 50 vials per transect in three different elevated locations of Pocosol, Soltis, and La Selva. The data yielded significant results of ants preferring different nutritional agents dependent on elevation. The Pocosol location had a p-value of <0.01 and favored the protein treatment. The Soltis location had a p-value of 7.81E-13 and favored the lipid treatment. The La Selva location had a p-value of 0.0365 and favored the lipid and protein treatment. Due to the results showing the varying nutritional preferences of ants in different elevations, the pest ant colonies can be specifically targeted with appropriate baits
A Study on The Effects of Different Chemical based and Natural Pesticides on Gryllodes sigillatus
No full textCrickets, although not known to be direct vectors for transmitting diseases, they are considered to be a nuisance species and can affect an individual\u27s health indirectly.The cricket Gryllodes sigillatus, also commonly known as the tropical house cricket or as the decorated cricket, is in the order of Orthoptera and family Gryllidae. Much like the cockroach and the common house fly, Gryllodes sigillatus can be found in homes and as a result, can cause problems such as fabric damage, fabric staining, food contamination, and create incessant chirping. Gryllodes sigillatus was chosen as our experimental subject species because of its common distribution around the Southern part of the US border. Our experimental study provides information on the efficiency and effects of different chemically and natural based pesticides can have on the species Gryllodes sigillatus. Specimens were observed over a set time interval in three separate trials, followed by a discussion of the benefits of using natural pesticides instead of chemically based pesticides was made based on our data
Examining Tegmina Polymorphism in Leaf-Masquerading Katydids (Orthoptera: Tettigoniidae)
No full textInsects employ a wide array of defensive mechanisms to avoid predation in the wild, evolving highly complex strategies for mimicking a wide range of organisms from other predators to surrounding foliage in the environment, all in an attempt to handicap predators’ ability to maintain a clear record of prey images to hunt. Cryptic insect species often evolve further mimicry strategies such as polymorphs and masquerade in order to provide a far more diverse range of forms, with even further variation of form seen through sexual dimorphism. Frequent and complex instances of polymorphism and cryptic masquerade can be found within the Orthopteran subfamily pterochrozinae (Orthoptera: Tettigoniidae), often posing taxonomic dilemmas as the hugely diverse and convincing forms are unable to be distinguished from eachother. This subfamily contains the genus Mimetica whose precision and accuracy in mimicking leaf appearance, as well as the wide diversity in shape and high color variation, make it an ideal system for observing of polymorphic variation of leaf forms. This experiment attempted to clarify the species relationships within Mimetica, in addition to developing a deeper understanding of the function and importance of polymorphs in insect populations and ecological phenomena in order to ascertain if the katydid species incisa, crenulata, viridifolia, mortuifolia, tuberata, and simoni within Mimetica display a distinct number of cryptically polymorphic forms versus continuous variation by utilizing digital landmark based geometric morphometric software to analyze the tegmina. Tps analyses provided strong support for the existence of sexually dimorphic forms for all species, and a lack of distinction in form within all incisa specimens, suggesting a more effective polymorph. In contrast, simoni and viridifolia specimens displayed the clearest distinction in form, supporting the possibility of the existence of discrete polymorphs in this genus but requiring further refined morphometric analyses
Ant Restaurant: Fire Ant Attraction to Varying Food Groups
No full textSolenopsis invicta or the red imported fire ant is a well known and common pest in Texas. They can be seen in many different grassy habitats and affect both people and animals. Their most distinctive feature is the red head and thorax and black abdomen. Due the aggressiveness of this species of fire ant, it is often very sought after how to get rid of them, especially when they invade homes. It is often annoying to see ants all over any type of food that is left outside. However, this can be used as an advantage to get rid of them. Baiting is a very affective technique; it is just important to know what attracts them the most. This experiment tests 8 different foods, with differing carbohydrate, protein and lipid contents to see which are the most attractive to ants. Three different “plates” will act as three different trials and the number of ants of each food on each plate will be counted. A system of how ants are counted is also specified to make sure they don’t get counted twice. Finally, based on these results, inferences on which baits would be the most effective can be discussed. In addition, the contents an ideal bait can also be explained as well, leading to further research on Solenopsis invicta baiting techniques
The Capability of Acuminate Ice-generated Puncture Lethality and Depth in Mammalian Torso
No full textDuring certain months of the year and depending on where we are in the world, we can walk outside and witness icicles forming on overhangs of houses. We might even witness a few children playing with these icicles, using them as weapons to “save a princess” by “slaying a dragon”. Besides jokes and the fantasies of children like the one aforementioned, the icicle is not looked at as something with the possibility of causing actual, fatal injury. In this experiment, we explore that possibility to its necessary extent. We evaluate the efficiency of spikes of ice when used to stab a meat body, observing wound depths and durability of the ice during and before action. We found that the spikes of ice were able to pierce meat comparable to the human abdomen with enough depth to compromise any of the vital organs in that region, including the liver. But otherwise, the chest region proved almost impenetrable to the spikes of ice, leaving the heart and other major arteries surrounding it seemingly unreachable. Overall, this experiment confirmed the capability of ice, when acuminated, to be a lethal instrument
Survey of Mosquitoes on Lake Houston and surrounding Houston Areas
No full textAfter a move from a suburb in the Houston area to Lake Houston (Northeast of downtown Houston), it was observed that the mosquitoes during the summer seemed to be much more prominent on Lake Houston than previously in the suburb. This noticeable difference triggered the question of what types of mosquitoes preferred what kinds of locations and why. To understand and evaluate this question, a survey of various mosquito types across the Houston metropolitan areas was performed. Traps were set up in five cities of different environments, mainly varying in their proximity to specific environmental differences (i.e. lakes, woody areas, downtown etc.) Mosquitoes were collected over a weekend in April, a month reported to have one of the highest rates of mosquitoes present (Nava, 2016). Through research, it was determined that the most prevalent mosquito types in all of the Houston area were Culex species, Anopheles species and Aedes species. Each of this mosquito types have been reported in high numbers during the late Spring and Summer months in all of Houston, but there is little data on how each type is distributed in each area. Through the research, it was hypothesized that Anopheles species would be most prevalent in areas near water and was upheld by the data from the experiment. Knowing this information about the prevalence of certain types of mosquitoes in each area can better help create a mechanism for trapping in each place. Each types of mosquitoes are drawn to various things, for instance, Anopheles prefer to stay on standing water and knowing these preferences can be applied to a better prevention (Mosquito World). With the rise of many serious mosquito transmitted diseases like Zika and West Nile, knowing specifically what mosquitoes are in which area are helpful to each community in protecting themselves from these threats that are associated with each mosquito type
Effect of Food Availability on the Rate of Zophobas morio (Coleoptera: Tenebrionidae) (F.) Pupation
No full textZophobas morio (Coleoptera: Tenebrionidae) (F.) larvae are insects that can be found at most pet stores. The larvae are common sources of food for insectivorous pets, but there is a new interest in the potential for these as sources food for humans. The aim of this study was to determine whether the absence of food would affect the time it takes for the larvae to pupate. Larvae were divided into two groups: one with food and one without food. The days it took the larvae to reach the pupal stage were monitored and noted. By the end of the thirty days that were dedicated to this study, only six of the fourteen larvae had pupated. Larvae that either did not pupate or died during the length of the experiment were recorded with a value of zero. Raw data indicated that the group without food pupated nearly twice as fast as the group that did have food. However, the results of a one-tail independent t-test showed that there was no statistically significant difference between the two groups. The t stat value for this test, 0.46, was not greater than the t critical one-tail value, 1.81, indicating that the larvae did not pupate faster in either group and the null hypothesis could not be rejected. The results of this test could have been a due to the small sample size in this experiment as four larvae from one group and two larvae from another group are not a large enough sample to gather accurate data
Comparative Repellency of Common Essentials Oils and Commercially Available Repellents Against the German Cockroach (Blattella germanica)
No full textBlattella germanica (Blattodea: Ectobiidae), the German cockroach, has been known to be attracted to various bacteria-laden surfaces such as feces and garbage, as well as food. The tendency for these cockroaches to transfer bacteria onto the food humans eat present a method of entry for bacteria into the human system, and therefore contribute to overall mechanical disease transmission. B. germanica does not only contribute to disease transmission, but also to a large amount of asthmatic reactions in humans. These negative effects, combined with this species tendency to live inside human dwellings, heightens the need for an effective repellent against them. Since repellents require application within homes, it is essential that it is non-toxic and safe. A current option other than manufactured repellents may be the use of essential oils. In this study, a combination of various commercially-available insect repellents as well as essential oils were assessed in terms of repellency against B. germanica. This assessment was completed through the observation of the amount of time necessary for a B. germanica cockroach to cross over a substance-treated filter paper when attracted by white bread. It was found that, while certain commercially-available repellents proved more effective than some essential oils, essential oils still demonstrated significant repellency and were more repellent than DEET, a commercial repellent with known adverse effects. This provides implications for further development of safer and potentially less expensive repellents, particular in future usage in Integrated Vector Management programs
Efficacy of Castile Soap at Reducing Numbers of Demodex spp. (Trombidiformes: Demodicidae) on Females
No full textStudies into the complex relationship between Demodex spp.(Trombidiformes: Demodicidae) are important as they may provide insights into the physiology of certain skin conditions. Demodex spp.is a type of mite that feeds off of the oils that are produced in the follicles and pores of the face. Normally, this relationship is harmless and mutualistic in nature. Demodicosis is a skin condition caused by overpopulation of Demodex spp., new, non-invasive treatments for demodicosis are desirable, as they could improve quality of life for individuals that have minimal access to healthcare. In this study, the effects of unscented castile soap are assessed regarding Demodex spp.populations. Liquid glue and tape were used to collect mites; the mites were then placed on a microscope slide for observation. Prior to collection, each non-control subject washed their face with castile soap. Samples were gathered over a nine day period to allow for the observation of potential trends. The results show that there were no significant differences in numbers of face mites by use of castile soap versus water
The Effects of Sorghum Volatiles and Sugarcane Aphids on Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) Attraction to Plants
No full textAbstract:Coccinella septempunctata and Harmonia axyridis are incredibly effective controls for insect pests in crops. We tested their ability to use olfactory cues to choose the plant with aphids on it. We used two strains of Sorghum bicolorone being the normal susceptible strain while the second was resistant to aphids. The tests conducted were ultimately to determine which strain of sorghum the ladybeetles would favor, and whether or not the ladybeetle would prefer the plants with aphids on them. When aphids were present, no significant difference between susceptible and resistant was found, but when there were no aphids the susceptible plant attracted more predators. This could suggest that there is some kind of chemical or volatile that the susceptible plant has that the susceptible plant does not. Further study of the volatiles that the two strains produce would be necessary as well as more replicants of the two strains with no aphids.