Tag: Biology

Title: Creation of a Dichotomous Key of Mosquito Larvae for Use by the Hunterdon County Vector Control Program

Abstract: Understanding the identity and distribution of mosquito vector species is paramount in proper vector control methods. This project aimed to aid in identification by creating a dichotomous key of mosquito larvae present in Hunterdon County, New Jersey to be used by their Mosquito Control Program. Numerous larval mosquito species from Hunterdon County were collected, preserved, and used for photographing morphological features used in this key to illustrate the identifying structures of each species within the key. To date, there are no mosquito identification keys of this type for Hunterdon County Vector Control Program. The key will help with identifying important mosquito species such as Culex pipiens, Aedes aegypti, and Aedes albopictus, which are the main vectors for the West Nile and Zika Viruses.

Keywords: mosquito, larvae, Hunterdon County

Title: The effects of insect herbivory on enzymatic activity in Ailanthus altissima (Tree of Heaven)

Abstract: My research compared the effects of mechanical wounding and insect herbivory on enzyme expression in the leaves of Ailanthus altissima. A. altissima is an invasive tree that has very few predators. Our experiment was conducted to determine whether the enzyme polyphenol oxidase was a possible inhibitor of insect activity, based on whether the amount of enzyme increased with wounding or herbivory.

Keywords: enzymes, ailanthus, tree of heaven, wounding

Title: Plant extract effect on mosquito mortality: determining the efficacy of an ailanthone extract to control adult mosquitoes.

Abstract: Due to the negative environmental impact and resistance to chemical control agents, the development of biological control or biocides has increased significantly over the past half century. However, the potential of plant extracts as potential control agents has only recently begun to attract attention. Tree of Heaven Ailanthus altissima is a non-native tree from Asia and produces the allelopathic compound, Ailanthone. This compound is anecdotally known to have insecticidal qualities. The purpose of this study was to examine the potential of Ailanthone as a botanical insecticide on adult mosquitoes. The leachate extraction method was utilized on newly emerged, mature, and senesced leaves to determine if leaf age influenced extract potency on adult mosquito survivorship. Three species of mosquitoes Aedes aegypti, Anopheles quadrimaculatus, and Culex quinquefaciatius and one non-target species, Painted Lady butterflies (Vanessa cardui) were treated with serial dilutions of ailanthone via two methods: 1) through spray contact exposure and 2) through sugar meal feeding. Adult mosquitoes (n=25 per cage; 3 cages per treatment) were exposed to 100, 75, 50, and 25% dilutions of A. altissima extract from either leachate or macerated leaf extractions. Mosquitoes were monitored for 24 hours to quantify survivorship. Adult mosquito mortality varied significantly among dilution factors and leaf age. These findings indicate that an invasive plant extract that the plant uses both as an herbicidal weapon against plant competitors and an insecticidal tool to deter insect herbivores may have potential as a biological control strategy for several major mosquito vectors of human disease pathogens.

Keywords: mosquito, plant extract, ailanthone

Title: Affects of water soluble Ailanthus altissima extract on larval growth and development of Aedes aegypti

Abstract: This study focuses on impacts of aqueous extract of Ailanthus altissima, the invasive Tree of Heaven, on development of Aedes aegypti, the Yellow Fever mosquito. A. aegypti is a common vector for many viral pathogens that have impacted world health; therefore, control of their populations is imperative and usually accomplished through application of chemical insecticides. This study seeks to explore the effects of a natural plant extract on insect body size and adult emergence time to assess effectiveness of possible insecticidal compounds. Targeted were larvae of the yellow fever mosquito. Extract of Ailanthus altissima was selected for its production of herbicidal compounds which may regulate growth and development of some insects. Extracts were obtained from plant tissues and applied to rearing trays of A. aegypti . Results were analyzed for significance by ANOVA and regression analysis to determine the effects of water soluble extracts o A. altissima; on A. aegypti larvae.

Keywords: water soluble, larva, tree of heaven

Title: The Effects of Endocrine Disrupting Chemicals on Avian Physiology and Behavior

Abstract: Endocrine disrupting chemicals (EDCs) impact survival and reproduction by upsetting the intricate hormonal signaling that orchestrates physiological and behavioral responses to the environment. Last Fall, I conducted an intensive literature review to initiate the fact-finding stages of a developing, long-term EDC research project led by MU Biology faculty. My research focused on 1) the known effects of EDCs on avian reproductive physiology and behavior, and 2) the potential for EDCs to bioaccumulate from aquatic insects to their avian predators. My findings provide a basis for defining project goals, refining testable hypotheses, and guiding experimental design. This spring, I am expanding my research to 1) investigate tractable methodology for measuring EDC loads in various sample types, and 2) locating potential research sites within Pennsylvania watersheds. I will present an overview of the proposed EDC project and a synopsis of my findings regarding the bioaccumulation of EDCs and their effects on birds.

Keywords: endocrine, watershed, EDC, avian

Title: Species Database of Roddy Pond: 2010-2014

Abstract: The goal of this project was to develop a species database for Roddy Pond at Millersville University, located next to the Millersville Science Center Complex. The objectives were to use this database to evaluate the number of animal taxa identified over time, document any invasive species, identify any animals of conservation concern and evaluate the frequency of student misidentifications of animals. Data for this analysis was collected from Zoology (BIOL 211) student PowerPoint presentations of animal diversity at Roddy Pond for each semester from 2010-2104. The results of these presentations were inventoried into an Excel spreadsheet. Results showed that species identification during the spring and fall was higher compared to the summer and that there were low numbers of invasive species and species of conservation concern. In addition, student misidentifications of animals decreased from 2010-2014. Future efforts in further developing this database are planned.

Keywords: Roddy pond, animal taxa, animals, species database

Title: The characterization of microbiota changes after larval mosquito treatment in post-Hurricane Sandy tree divot habitat in Hunterdon County, NJ

Abstract: Natural disasters such as hurricanes and other major storm events can provide the conditions for increases in suitable mosquito habitat and resulting mosquito populations. Mosquito control in these ephemeral habitats often includes bactericides (eg Bti) or insect growth inhibitors (eg Methoprene) that could affect the mosquito internal microbiome. The objectives of this study were to characterize hurricane-created tree divot habitat and mosquito and microbial diversity within these ephemeral habitats, pre/post mosquito control treatments. Physical/chemical data were collected from 21 tree divots pre/post Bti and Methoprene application. Surface microlayer, subsurface water, and mosquito samples were also collected and characterized using 16sRNA amplicon metagenomic sequencing. The microbial community structure of the water and the internal microbiomes of the mosquito larvae varied between divots and treatment, suggesting potential effects of control methods on habitat and insect microbial ecology that may provide new information on additional control targets in larval mosquitoes.

Keywords: mosquitoes, mosquito control, microbiome, DNA sequencing

Title: Neuroendocrine and Genetic Bases of Alternative Behavioral Strategies in the Polymorphic White-throated Sparrow

Abstract: The purpose of our study was to investigate the neuroendocrine and genetic basis of reproductive strategies in the white throated sparrow. This bird exhibits two plumage morphs, white-striped (WS) and tan-striped (TS), which segregate with a chromosomal rearrangement. These two morphs exhibit alternative behavioral phenotypes; WS individuals show more aggression, less parenting, and more mate-seeking compared to TS individuals. We quantified gene expression for the hormone vasoactive intestinal polypeptide (VIP) in the brains of behaviorally characterized wild birds. We found that VIP gene expression in the infundibular nucleus (INF) was higher in TS males than in WS males. VIP produced in the INF may act as a prolactin-releasing factor; prolactin is a hormone that can promote parenting. VIP expression in the anterior hypothalamus (AH) was higher in WS than in TS individuals; here, VIP is thought to promote aggression.

Keywords: White-throated sparrow, Neuroendocrinology, genetics, VIP, alternative behavioral phenotypes, parenting, aggression