Biological disturbance was found to be one of the most important mechanisms control1ing community organisation in the temperate sub-tidal region. The different types of biological disturbance structuring three encrusting communities were investigated on the east coast of Northland, New Zealand. The operation of each type was determined and the rate of disturbance measured. Experimental exclusion treatments were set up to demonstrate the effects of the major disturbance agents on community structure. The urchin Evechinus chloroticus was the most abundant agent of biological disturbance and affected the widest spectrum of encrusting organisms. The abundant balistid fish Navodon scaber was another major agent of biological disturbance in this region. Disturbance of algal populations also resulted from a guild of abundant herbivorous gastropods. Two episodes of fungal/bacterial infection degraded numbers of the large sponges Ancorina alata and Polymastia fusca. The operation of the different disturbance agents was found to be generally unpredictable in both time and space. There was no escape from biological disturbance for encrusting organisms in either small or large size. Re-occupation processes on patches of free primary space were investigated both experimentally and by using settlement plates (artificial free space patches). Recruitment was found to be irregular in space and time, especially for long-lived sessile organisms. Settlement processes as well as growth and mortality of newly settled organisms were investigated with a view to understanding community development. Only one verifiable example of substrate preparation or biological succession was found to operate in the communities studied. It is postulated that community organisation is flexible and not rigidly directed along a single successional pathway. Multiple developmental pathways and multiple stable configurations are possible in the same locality, resulting from the operation of different disturbance regimes.

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Biological disturbance was found to be one of the most important mechanisms control1ing community organisation in the temperate sub-tidal region. The different types of biological disturbance structuring three encrusting communities were investigated on the east coast of Northland, New Zealand. The operation of each type was determined and the rate of disturbance measured. Experimental exclusion treatments were set up to demonstrate the effects of the major disturbance agents on community structure. The urchin Evechinus chloroticus was the most abundant agent of biological disturbance and affected the widest spectrum of encrusting organisms. The abundant balistid fish Navodon scaber was another major agent of biological disturbance in this region. Disturbance of algal populations also resulted from a guild of abundant herbivorous gastropods. Two episodes of fungal/bacterial infection degraded numbers of the large sponges Ancorina alata and Polymastia fusca. The operation of the different disturbance agents was found to be generally unpredictable in both time and space. There was no escape from biological disturbance for encrusting organisms in either small or large size. Re-occupation processes on patches of free primary space were investigated both experimentally and by using settlement plates (artificial free space patches). Recruitment was found to be irregular in space and time, especially for long-lived sessile organisms. Settlement processes as well as growth and mortality of newly settled organisms were investigated with a view to understanding community development. Only one verifiable example of substrate preparation or biological succession was found to operate in the communities studied. It is postulated that community organisation is flexible and not rigidly directed along a single successional pathway. Multiple developmental pathways and multiple stable configurations are possible in the same locality, resulting from the operation of different disturbance regimes.

Biological disturbance was found to be one of the most important mechanisms control1ing community organisation in the temperate sub-tidal region. The different types of biological disturbance structuring three encrusting communities were investigated on the east coast of Northland, New Zealand. The operation of each type was determined and the rate of disturbance measured. Experimental exclusion treatments were set up to demonstrate the effects of the major disturbance agents on community structure. The urchin Evechinus chloroticus was the most abundant agent of biological disturbance and affected the widest spectrum of encrusting organisms. The abundant balistid fish Navodon scaber was another major agent of biological disturbance in this region. Disturbance of algal populations also resulted from a guild of abundant herbivorous gastropods. Two episodes of fungal/bacterial infection degraded numbers of the large sponges Ancorina alata and Polymastia fusca. The operation of the different disturbance agents was found to be generally unpredictable in both time and space. There was no escape from biological disturbance for encrusting organisms in either small or large size. Re-occupation processes on patches of free primary space were investigated both experimentally and by using settlement plates (artificial free space patches). Recruitment was found to be irregular in space and time, especially for long-lived sessile organisms. Settlement processes as well as growth and mortality of newly settled organisms were investigated with a view to understanding community development. Only one verifiable example of substrate preparation or biological succession was found to operate in the communities studied. It is postulated that community organisation is flexible and not rigidly directed along a single successional pathway. Multiple developmental pathways and multiple stable configurations are possible in the same locality, resulting from the operation of different disturbance regimes.

Biological disturbance was found to be one of the most important mechanisms control1ing community organisation in the temperate sub-tidal region. The different types of biological disturbance structuring three encrusting communities were investigated on the east coast of Northland, New Zealand. The operation of each type was determined and the rate of disturbance measured. Experimental exclusion treatments were set up to demonstrate the effects of the major disturbance agents on community structure. The urchin Evechinus chloroticus was the most abundant agent of biological disturbance and affected the widest spectrum of encrusting organisms. The abundant balistid fish Navodon scaber was another major agent of biological disturbance in this region. Disturbance of algal populations also resulted from a guild of abundant herbivorous gastropods. Two episodes of fungal/bacterial infection degraded numbers of the large sponges Ancorina alata and Polymastia fusca. The operation of the different disturbance agents was found to be generally unpredictable in both time and space. There was no escape from biological disturbance for encrusting organisms in either small or large size. Re-occupation processes on patches of free primary space were investigated both experimentally and by using settlement plates (artificial free space patches). Recruitment was found to be irregular in space and time, especially for long-lived sessile organisms. Settlement processes as well as growth and mortality of newly settled organisms were investigated with a view to understanding community development. Only one verifiable example of substrate preparation or biological succession was found to operate in the communities studied. It is postulated that community organisation is flexible and not rigidly directed along a single successional pathway. Multiple developmental pathways and multiple stable configurations are possible in the same locality, resulting from the operation of different disturbance regimes.

The German cockroach, <i>Blattella germanica</i>, is a common insect pest in the United States that causes aesthetically unpleasing collections of feces on household surfaces including walls, floors and furniture (Nalyanya et al. 2009, Pomés et al. 2002). The German cockroach is economically and medically significant not only because it contaminates food with feces, but also because the German cockroach is a physical and mechanical carrier of pathogenic bacteria, viruses and intestinal parasites (Hamu et al. 2014). In addition to being a vector, the German cockroach also produces allergenic “Bla g” proteins in multiple tissues and in its feces, including the inactive aspartic protease Bla g 2 (Arruda et al. 1995, Pomés et al. 2002). Bla g 2 has been documented by Arruda et al. (1995) to exist in several German cockroach tissues, however the abundance of Bla g 2 in adult male-exclusive structures known German cockroach tergal glands was not known. Tergal glands are structures found in numerous insect species that may contain proteins, sugars, and pheromones, and German cockroach tergal glands secrete a feeding stimulant that is consumed during courtship as well as outside of the context of courtship by conspecifics of differing sexes and life stages. Because of this wanted to assess if Bla g 2 was a constituent of the tergal glands. Furthermore, although Bla g 2 protein expression has been detected in several cockroach tissues, studies that link protein expression in various life stages and tissues with mRNA and protein abundance profiles have not been conducted. The goals of my dissertation were to measure the relative abundances of <i>Bla g 2</i> mRNA and protein in different tissues and life stages, as well as identify all the proteins in the tergal glands, including the proteins that interact with Bla g 2. The molecular tools used to complete these objectives included RT-qPCR, Western blotting/ immunoblotting, co-immunoprecipitation, and liquid chromatography-tandem mass spectrometry (LC-MS). I found that Bla g 2 protein was detected in each tissue analyzed, including the tergal glands, and that protein expression was relatively high in adult males and their tergal glands in comparison to nymphs and females. <i>Bla g</i> <i>2</i> mRNA transcript levels were also relatively high in male tergal glands and adult males. My proteomic analysis detected three isoforms of Bla g 2 in the tergal gland secretions. <div><br></div><div>Detection of multiple isoforms in the tergal gland secretions prompted me to perform LC-MS peptide sequencing with entire tergal glands, and I was able to identify not only Bla 2 isoforms, but other protein isoforms present in the glands. Because isoforms are proteins with similar peptide sequences that originate from the same gene or gene family but typically have different structures and functions, assessing the identities and abundances of allergen isoforms that may reside in the tergal glands helped to inform me of the medical significance of the tergal glands. I was able to detect 608 proteins in the tergal glands, and LC-MS of the tergal gland secretions alone detected 303 proteins. In the co-immunoprecipitation experiments, I was also able to detect proteins that exclusively co-immunoprecipitate with Bla g 2 in the tergal glands, despite being present in the male and gravid female whole bodies as well.<br></div><div><br></div><div>I used TargetP-2.0, a bioinformatics prediction server, to identify which proteins in the tergal gland secretions were actually transported from tissue specific cells to secretions due to the presence of a signal peptide. This method was used to filter out proteins that may have contaminated the secretions from external sources, such as the wings or feces, and to filter out proteins that originated from damaged or apoptotic tergal gland cells. I also used Blast2GO, bioinformatics software that calculates the functional and locational annotations of proteins, to annotate the proteins that were profiled in the tergal glands. The data show that proteolysis is the most common biological process in the tergal gland secretion proteins that were predicted to have a signal peptide. I also found that translation is the most common biological process in the tergal glands.<br></div><div><br></div><div>In conclusion, my research on the inactive aspartic protease Bla g 2 has led to novel findings including: (i)<i> Bla g 2 </i>mRNA expression profiles in multiple <i>B. germanica</i> tissues, life stages, and sexes, (ii) Bla g 2 protein expression profiles in multiple <i>B. germanica</i> tissues, life stages, and sexes, (iii) Identities of proteins in the tergal gland secretions and tergal glands, (iv) Identities of proteins that co-immunoprecipitate with Bla g 2 in the tergal glands, adult male whole body and gravid female whole body, (v) and annotation of the molecular functions, biological processes, and cellular components proteins found in the tergal glands.<br></div>

<p> Though it is well established that insects are attracted to decomposing vertebrates, little is known about the mechanism of attraction. Olfaction is thought to be the primary sense involved in resource location by necrophilous insects, and several studies have attempted to identify cadaveric-produced volatile organic compounds (VOCs) that contribute to insect attraction. This previous research has been completed almost exclusively in lab settings, with no field studies to verify these findings. </p><p> The goal of my thesis was to test necrophilous insect attraction to nine cadaveric VOCs (1-butanol, 1-pentanol, <i>p­</i>-xylene, <i>o</i>-xylene, ethanol, cyclohexanone, acetamide, dimethyl disulfide, and dimethyl trisulfide) in a field setting. Pitfall traps at six research locations were baited with the chemicals for one week. Specimens collected from the traps were identified and species assemblages were compared to those of a pig carcass. Replicates were conducted in fall 2018 and spring 2019. </p><p> Two chemicals were identified as important attractants for a variety of necrophilous insects: dimethyl disulfide and dimethyl trisulfide. These chemicals were especially attractive to <i>Phormia regina</i>, a blow fly (Diptera: Calliphoridae) found worldwide. VOC insect communities did not include all of the insects found on carcasses, possibly indicating the necessity of chemical blends for effective attraction. This study is only the second study to test necrophilous insect attraction in a field setting. </p>

The focus of this dissertation is on bed bug thermal biology. How bed bugs react to heat exposure at the population, behavioral, and physiological levels was explored. The thermal tolerance of different bed bug populations and sublethal effects heat exposure were investigated. The temperatures that cause bed bugs to flee from their harborages was determined using a custom made arena. How bed bug physiology changes after heat exposure was determined using RT-qPCR. Finally, how conspecifics react to bed bugs that have been lethally exposed to heat was determined using still air bioassays.<br>

<p> As the root microbiome’s role in plant defenses against herbivory becomes clearer, scientific focus has lingered on a single side of plant defenses: resistance. Its counterpart, tolerance, is comparatively overlooked despite its power as an evolutionarily sustainable mitigator of herbivore damage. This thesis seeks to supplement our limited understanding of the extent to which tolerance to herbivory may be influenced by rhizosphere microbial communities. First, in an agricultural field setting, I (1) quantified domesticated tomato cultivar and wild ancestor tolerance to herbivory form the specialist tobacco hornworm (<em>Manduca sexta</em>) and (2) characterized the bacterial and fungal rhizosphere communities associating with high and low tolerance plants. In a subsequent greenhouse experiment, I grew these same tomato lines in either sterilized or unsterilized soil and re-challenged plants with tobacco hornworms to tease apart the contributions from host plant and rhizosphere microbiome in expressing tolerance to herbivory. In the field, wild tomato lines excelled at tolerating hornworm herbivory, while their domesticated counterparts suffered 26% yield losses under herbivory. Rhizosphere community characteristics were most reliably shaped by timepoint of rhizosphere sampling, and more subtly by tomato line and herbivory treatments. Fungal and bacterial community traits that associated with high tolerance lines include (1) high diversity, (2) resistance to community shifts under herbivory, and (3) the abundance of ASVs belonging to <em>Strenotrophomonas</em>, <em>Sphingobacterium</em>, and <em>Sphingomonas</em>. When re-challenging these lines with hornworm herbivory in the greenhouse, expressed tolerance to tobacco hornworm damage was inverted from field trends. Though wild lines suffered yield losses when grown in +microbiome treatments, we found no consistent interactions between herbivory and microbiome treatments that might indicate that +microbiome treatments either helped or hampered plant expression of tolerance to herbivory under greenhouse conditions. These experiments shed light on what role, if any, the rhizosphere microbiome plays in plant tolerance to herbivory. Ultimately, understanding the qualities of tolerance-conferring microbiomes can (1) open avenues through which plant defenses may be amended in pest management, either through microbial inoculants or plant breeding efforts aimed at enhancing crop recruitment of beneficial microbiomes; and (2) ameliorate our understanding of the tripartite interactions between host plants, their rhizospheres, and their specialist herbivores. </p>

<p>  </p> <p>Urban farmers face many unique challenges associated with the urban environment in which they produce. One of the most expensive and limited resources is access to healthy soils. There is often low organic matter and industrial contaminants present in urban soils, resulting in the need for remediation, such as capping and importing topsoil and compost. Recently, black soldier fly larvae (<em>Hermetia illucens; BSF)</em> have been recognized as an efficient organism used to break-down organic matter and produce a soil amendment comparable to traditional fertilizers. These fly larvae can feed on a wide range of organic waste (plant material, biosolids, food waste, etc.), can break down contaminants such as pharmaceuticals or pesticides, and impact the bioavailability of heavy metals. The resulting material is a digestate that can be applied as a soil amendment, much like the vermicomposting processes of worms. Fly pupae can be harvested and used as a nutrient dense feedstock for livestock or reared to adults to continue the cycle of composting.  Knowledge gaps remain regarding the impact of feedstock on the nutritional quality of the digestate for crop production and the application and implementation of BSF composting on-farm. We found that larval weight is unaffected by diet streams, however, larval length is improved on food waste streams. Additionally, crop growth varies when grown with BSFL digestate.</p>