Variation in Culturable Gut Microorganisms of the Catalpa Sphinx Caterpillar (Ceratomia catalpae)

Microbial symbionts are important for host organisms, and insects rely on the communities of microorganisms in their guts for several functions. Despite what we are starting to understand of their importance, gut microorganisms have been censused in relatively few insect species. In this study, we examined the types of culturable gut microorganisms in larvae of the catalpa sphinx, Ceratomia catalpae. The gut microbes of this caterpillar are of interest because it feeds only on catalpa trees, and sequesters catalpol from the plant for its own chemical defense. We cultured gut contents of 27 caterpillars from three populations on nutrient agar, and five distinct bacterial colony morphologies were recognized. Four of these morphologies were Gram-negative, and all five were cocci. Future studies with this caterpillar can explore the influence of these bacteria on its ability to feed on catalpa trees and sequester catalpol

Prey Species Influences Culturable Gut Symbionts of a Generalist Predator

Gut microorganisms have important influences on animals, and diet of animals can affect what microorganisms are present. Little research has been done on the gut microbes of predatory arthropods, and it is not currently well known whether gut microbes of predators are influenced by different types of prey. In this study, we compared the culturable gut microbes of the predatory stinkbug Podisus maculiventris when fed either Ceratomia catalpae larvae, which sequester plant toxins, or Trichoplusia ni, which do not. We were able to culture two additional bacteria types from P. maculiventris nymphs reared on the C. catalpae, suggesting that feeding on different prey species may alter the makeup of the gut microbe community in this predator. Further studies with both culturing and culture-independent techniques can offer insights into how feeding on different prey species affects gut microbe communities of predators

#42 - Deterrence of Ants by Chemical Compounds from Six Southeastern Plants

Ant interactions with plants are diverse; therefore, one of the most important aspects of ant-plant interactions is the exposure of ants to plant compounds. These compounds can serve as cues to either enhance or deter recruitment of ants to food. The purpose of this experiment is to measure the recruitment of ants to extracts that were made from six different southeastern native plants, all of which display a wide range of chemical diversity. Seven different extracts were mixed using a sugar solution. Six of the extracts had the dried leaf material of the plants Solidago altissimus, Verbesina virginica, Callicarpa americana, Pycnanthemum muticum, Catalpa speciosa, and Cercis canadensis dissolved in the solution while the seventh was a control. The experiment was conducted for 15 minutes per solution and the number of ants was counted at each one-minute interval. Overall, the ants were attracted more towards the control extract. During the first four minutes, the mean number of ants attracted to the extracts containing Verbesina virginica and Catalpa speciosa were high, however, this number declined over time. No significant signs of recruitment were shown by the other four extracts. Collectively, the data suggests that ants were more attracted to the sugar control. This conclusion presents an application that the chemistry of plant compounds may have a strong significance to ant deterrence

The Trichoplusia Ni Gut Microbiome and Its Derivation from the Phyllosphere of Its Food Plants

Insects are the most abundant and diverse animals on planet Earth and rely on their diverse microbiomes to be so. The insect gut microbiome is vital in the growth and development of many insect species. Trichoplusia ni, the cabbage looper, is a generalist herbivore, but little is known about its microbiome. In this study, a metagenomic analysis of fecal samples was used to determine the effect of diet on the microbiome of T. ni larvae. Larvae were reared on six plant species, the microbiome was sampled from fecal material, and the phyllosphere was sampled from leaves the larvae ate. Bacteria were identified using 16S ribosomal RNA gene sequences, and diversity was quantified. Similar phyla, classes, and families were found in both types of samples, suggesting T. ni larvae primarily obtain their gut microbiome from their diet. However, the gut microbiome of T. ni larvae is not identical to the phyllosphere, particularly in relative abundances, suggesting that other factors in the insect gut environment may further modify the diversity of the microbiome. This study adds to the growing body of evidence about the implications of diet for the insect gut microbiome

#15 - Assessing the presence of Wolbachia in the mosquito populations of Northeast Georgia, USA

Wolbachia, a Gram-negative bacterium that infects mosquitoes along with other arthropods, can suppress the spread of microfilaria through reducing the populations of mosquitoes that carry the heartworms. Historically, research has been conducted to use in the prevention of infections from parasites or viruses like Zika or yellow fever. It is important to understand ways of preventing the various infections from occurring not only by host prevention but through vector prevention or suppression. In the summer of 2018, a total of thirty-five adult female mosquitoes were collected in Oakwood, Georgia at the University of North Georgia in two locations between May 29, 2018 through August 10, 2018 to evaluate for microfilaria and Wolbachia. Following evaluation for microfilaria, DNA extraction from each mosquito was completed for polymerase chain reaction (PCR) testing to test for Wolbachia presence and absence. Data analysis is being continued at this time. Determining the presence of Wolbachia in our adult female samples could help us better determine ways to control mosquito populations to slow or halt the spread of ultimately fatal diseases, parasites, and viruses that are transmitted through adult female mosquitoes. Research conducted through PCR could lead to larger scale research projects sampling mosquitoes for this high-impact bacterium in the future

Corn Should Be a Food, Not a Fuel

Use natural gas as a transportation fuelSummer 201

13. Bugs in Bugs: Analysis of microbiota of Trichnoplusia ni Larvae

All multicellular organisms including plants and animals harbor a community of microbes called the microbiota. The gut microbiome plays an important role in digestion, immunity and overall health of an animal. Research has shown that the insect microbiome is associated with resistance to natural invaders, virulence, digestion, and reproductive success. The insect microbiome may also metabolize defensive compounds, and influence the ability of insects to associate with certain host plants. Recent research suggests that hornworm caterpillars (Manduca sexta) have no permanent microbiome; instead acquiring transient microbes from the plants they eat. In this project, students from two courses (BIOL1108K and BIOL2500L) collaborated to understand the acquisition of gut microbiome of Trichnoplusia ni, a nocturnal cabbage looper or commonly referred to as owlet moths. Biology 1108K collected fecal samples from T. ni larvae fed on various pre-selected plant diet. The fecal samples were suspended in saline, swabbed on nutrient agar plates, and incubated for 24 h at 37˚C. Bacterial colonies that appeared on these plates were then analyzed and characterized by BIOL2500L students. Our group comprising of four students analyzed three bacterial colonies using microbiological techniques learned in BIOL2500L. We investigated the colony and cell morphology, Gram reaction, antibiotic resistance and biochemical features of all three bacteria. We identified all three bacterial colonies to be Gram-positive Staphylococcus sp, which is interestingly part of the normal skin microbiota suggesting that humans and insects may share similar microbiota

PLANT AND ANIMAL INTERACTIONS IN THE “BOTANICAL LOST WORLD” OF THE BIBB COUNTY GLADES.

As arthropod populations continue to decline, it is imperative that sensitive ecosystems are continually monitored and associations between plants and arthropods are documented. The ketona dolomite glades of Bibb County, AL are prime examples of a sensitive ecosystems as they only occur over a very narrow range, contain eight endemic species and over 60 species of conservation concern. From 2016 to 2018, We observed and tracked the inter-specific interactions between populations of plants and arthropods, specifically class Insecta, in Kathy Stiles Freeland Bibb County Glades Preserve. In May of each year, undergraduate students from the University of North Georgia used ecological field techniques to observe evidence of plant-arthropod associations such as herbivory and parasitical behavior, identified plants to genus or species, and collected/identified insects. Four habitat types were chosen to observe and compare associations: large glade, small glade, mixed hardwood dominated forest, and a pine dominated forest. Multi-Dimensional Scaling Analyses(MDS) were performed between the habitats for each year to determine if habitat type was a good indicator of association types and if associations changed over time. The associations varied by habitat type with variation seen between the glades themselves as well, but most variation was driven temporally by year and due to a burn event that took place during the study time. The size and the habitat type surrounding any glade greatly influences the associations and assemblages found in said glade, and annual variation along with habitat type dictates which associations will be present within a plant community

24. NON-PREFERENCE OF THE CATALPA SPHINX, CERATOMIA CATALPAE (LEPIDOPTERA: SPHINGIDAE) TO INVERTEBRATE PREDATORS

ABSTRACT Aposematic traits such as bright contrasting coloration and gregarious feeding are often signals to predators that a potential prey is unpalatable. Larvae of Ceratomia catalpae, the catalpa sphinx, show aposematic traits and sequester catalpol, a secondary compound from their host plant Catalpa spp. Catalpol sequestration by other caterpillar species has been shown to deter both invertebrate and vertebrate predators, but the palatability of C. catalpae has not been explicitly tested. Choice tests with both spiders (Hogna carolinensis) and predatory hemipterans (Podisus maculiventris) showed that predators naïve to both C. catalpae and the alternate prey Trichoplusia ni and Manduca sexta preferred the alternate species, and that P. maculiventris that were exposed previously to T. ni also preferred T. ni. In non-choice tests, P. maculiventris grew significantly slower upon C. catalpae compared to M. sexta. These results suggest that C. catalpae, like other caterpillars that sequester catalpol, is unpalatable and that the catalpol is an effective chemical defense against invertebrate predators

Time is of the essence: Direct and indirect effects of plant ontogenetic trajectories on higher trophic levels

Physiological and morphological constraints during plant ontogeny affect the expression of numerous plant traits relevant to higher trophic levels, such as nutritional content and physical and chemical defenses. Yet we know little about how temporal variation in these traits can directly and/or indirectly mediate tri-trophic interactions, such as those between plants, their herbivores, and herbivore natural enemies. Using four distinct ontogenetic stages of Plantago lanceolata (Plantaginaceae) and the specialist herbivore Junonia coenia (Lepidoptera, Nymphalidae), we evaluated how ontogenetic changes in plant quality can: (1) directly alter plant-herbivore interactions through butterfly oviposition choice and caterpillar performance assays, and (2) indirectly alter herbivores susceptibility to higher trophic levels through caterpillars iridoid glycoside sequestration and immune defenses. Results showed that plant defensive traits increased over P. lanceolata development, with leaf tissues becoming tougher and plant allelochemicals (iridoid glycosides) occurring in higher amounts. Conversely, plant nutritional quality (water and nitrogen content) decreased as plants aged. These ontogenetic trajectories strongly altered both direct and indirect interactions between plants and higher trophic levels. Buckeye butterflies showed a stronger oviposition preference for younger developmental stages of P. lanceolata, laying on average 60% more eggs on juvenile than on reproductive plants. Feeding experiments with caterpillars showed that larvae feeding on juvenile plants showed faster relative growth rate and increased digestive efficiency compared with those feeding on plants in the reproductive stage. These individuals, however, acquired lower levels of sequestered chemical defenses than did those feeding on older P. lanceolata plants, potentially rendering them more susceptible to predation. Finally, host plant age altered the ability of a caterpillar to mount an immune response against simulated parasitoid eggs. Specifically, caterpillars reared on older plant life stages, and thus with higher levels of sequestered iridoid glycosides, showed a compromised immune response compared to those feeding on younger plant age classes. This study exemplifies how ontogenetic trajectories in plant traits can scale up to directly or indirectly alter tri-trophic interactions, which may have key implications for understanding temporal shifts in herbivore population and community structure.Fil: Quintero, Carolina. State University Of Colorado-boulder; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; ArgentinaFil: Lampert, Evan C.. University of North Georgia; Estados UnidosFil: Bowers, M. Deane. State University Of Colorado-boulder; Estados Unido