<p> The goldspotted oak borer (GSOB), <i>Agrilus auroguttatus</i> Schaeffer, is an invasive wood-borer associated with tree mortality in San Diego County, California since 2008, and is believed to have been introduced via infested firewood from southeastern Arizona. From 2011-2013, I recorded GSOB emergence holes on <i>Quercus agrifolia</i> trees at eight locations within San Diego County. I evaluated the effectiveness of crown class and purple prism traps as tools to monitor GSOB populations. I also identified possible tree and site characteristics that could explain the variation in GSOB population densities. Crown class was useful in monitoring GSOB populations unlike purple prism traps. Larger trees (>50 cm diameter at breast height), trees located near a stand's edge, and trees previously infested had the greatest emergence hole densities. Sites closer to GSOB's putative original point of infestation and those with an intermediate <i>Q. agrifolia </i> density (30-50 trees per hectare) had greatest infestation levels. </p>

<p> I sampled macroinvertebrates in May, July, and October 2008 in Uvas Creek, a reservoir-regulated stream in south Santa Clara County, California, to assess what factors (including canopy closure, turbidity, and stream flow) downstream of the reservoir were related to food availability for rearing juvenile Steelhead (Oncorhynchus mykiss). I found benthic and drifting macroinvertebrate biomass was considerably greater during most months in the more open-canopied two sites in the downstream reach as compared to the densely shaded, more turbid and silty two sites in the upstream reach. Abundance of important drifting aquatic invertebrates in May (chironomids, simuliids, and baetids) was proportional to benthic abundance, but large hydropsychids were relatively scarce in the drift. Terrestrial drift abundance correlated with canopy density, but differences were small compared to the substantial increase in aquatic drift in sunnier sites. Thinning of the canopy at select locations and reduction of sediment input to Uvas Creek and its tributaries due to vineyard and other operations could increase benthic macroinvertebrate productivity in the upstream reach, which would increase food availability for rearing juvenile Steelhead.</p>

<p> The burying beetle <i>Nicrophorus orbicollis,</i> through biparental care, raise their young on small vertebrate carrion which exposes them to microbial parasites and competitors. These interactions have led to elaborate strategies to combat microorganisms. Through the application of anal and oral secretions adults are able to preserve a carcass from which larvae feed, constituting a social immune response. Evidence suggests that larvae also contribute to this social immunity through their own secretions. Social immunity was tested through exposing larvae to an isolated food source with an experimentally elevated microbial signal, dead <i>Micrococcus luteus.</i> Larvae maintained higher lysozyme-like activity (LLA) in their oral secretions in response to the microbial signal. However, if personal immunity was compromised LLA was not maintained. Larvae and parents were tested for response to increased competition of feeding on fresh or aged carcasses with greater levels of decay. Larvae were not shown to alter LLA of their oral secretions but female parents did have a negative relationship of LLA in their oral secretions and in relation to brood size. Larvae had a negative relationship of phenoloxidase activity in their oral secretions in relation to brood size. This suggests influence of individual larval investment to social immunity affecting both parents and sibling investment. These findings show that oral secretions in <i> N. orbicollis</i> larvae, like adults, has adaptive antimicrobial activity which acts as a social immune response for defending a carrion food source and is sacrificed for personal immunity.</p>

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 68-02, Section: B, page: 0733. Adviser: Gene E. Robinson. Includes bibliographical references (leaves 113-132) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--Indiana University, Dept. of Biology, 2005. / Title from PDF t.p. (viewed Dec. 2, 2008). Source: Dissertation Abstracts International, Volume: 66-01, Section: B, page: 0152. Chair: Peter Kloosterman.

Doctor of Philosophy / Department of Entomology / Alberto B. Broce / Ludek Zurek / Stable fly, Stomoxys calcitrans (L.), and house fly, Musca domestica L., are two major pests affecting both confined and pastured livestock in the United States. It costs livestock producers millions of dollars annually to reduce populations of these two pests. Control of stable flies and house flies based on chemical insecticides is only marginally effective and unsustainable in the long term due to the development of insecticide resistance. This has created a demand for alternative methods which are environmentally friendly and cost effective for the management of these pests. Information on stable fly and house fly oviposition behavior and the aggregation and segregation of their immatures may help in an integrated pest management control program for these pests. This research identified specific bacterial species from the surface of stable fly eggs which are suspected of releasing chemical cues used to induce gravid females to oviposit at sites where eggs have been deposited and inhibit additional deposition of eggs in the same habitat when it is already colonized. My research also showed that stable fly and house fly larvae tend to be aggregated in distribution, even in apparently homogenous habitats, and to be spatially segregated from each other. Finally, I evaluated the vector competence of stable flies for an emerging food-borne pathogen, Enterobacter sakazakii, showing that this fly species is potentially a good vector for this pathogen.

Ant-plants provide ants with rewards such as housing and food in exchange for protection from herbivores. These protection mutualisms are complex webs of both direct interactions, such as ants feeding on host plant extrafloral nectar, and indirect interactions mediated by 'third party' species, such as ants consuming exudates from hemipterans feeding on the host plant. While some indirect interactions are well understood, in many cases our understanding is hindered by an incomplete picture of the relevant third-party species. In this dissertation, I explore third-party interactions of three obligately phytoecious ant species on the African ant-plant Vachellia drepanolobium (formerly Acacia drepanolobium) - Crematogaster mimosae, C. nigriceps and Tetraponera penzigi. First, I examine relationships between ants and fungi. I show behavioral differences towards fungi among the three ant species, and then use multiplexed amplicon sequencing to characterize their associated fungal communities. Each ant species harbors its own distinctive fungal community, and these communities are similar for each species even at two field sites separated by 200 kilometers. The ants may vector fungi when they colonize new host trees. T. penzigi most likely uses fungi as a food source, and fungi may also have nutritional or other growth implications for the host plant. Second, I investigate relationships between ants and 'myrmecophiles' - i.e. 'ant loving' arthropods that live alongside ants in the domatia. I show that myrmecophile communities differ among the three ant species, but are also highly context dependent, differing strongly between locations and sampling periods. Surprisingly, several species of myrmecophilous Lepidoptera are herbivorous, but are more commonly associated with the 'better' ant mutualists, C. mimosae, whose workers defend more effectively against browsing mammalian herbivores. My results show that plant ants shape both fungal communities and myrmecophile communities in domatia of their V. drepanolobium host plants. These third-party species may be viewed as 'extended phenotypes' of the ants, and are essential elements whose effects need to be incorporated into our understanding of the ant-plant protection mutualism. / Biology, Organismic and Evolutionary

No description available.

Master of Science / Department of Entomology / Jeremy L. Marshall / Sexual conflict is a process that occurs when the evolutionary interests of the sexes is not aligned. The theory began with Darwin in the 1800’s. His observations of sexual dimorphism and traits which did not seem to follow the rules of natural selection led him to the theory of sexual selection. Sexual selection resolved some of the issues which were noted in the evolutionary processes he observed but not all of them. For example, it did not explain traits which increased the male optimum fitness while decreasing the female optimum fitness. It was decades before the concept of sexual conflict was formulated, and even longer before the underlying mechanisms were understood. Sexual conflict is different than sexual selection and there are ways to differentiate which of these processes have occurred in a population. The main forms of sexual conflict are intralocus and interlocus conflict. These involve the interactions between alleles in the genome of the sexes. Intralocus conflict involves conflict at a single locus in the genome while interlocus conflict involves conflict between different loci. Interlocus conflict has been more extensively studied due to its association with sexually antagonistic coevolution (SAC). SAC draws the attention of scientists due to the possibility it is related to the fundamental biological process of speciation. Sexual conflict targets certain traits at defined periods in the mating process. These periods include first, the precopulatory stage which is before the act of copulation begins. Second, there is the stage during copulation but before fertilization of the embryo. Finally, there is the postcopulatory postzygotic stage which is after copulation has ended and fertilization has occurred. Each of these points in the process of mating has traits or behaviors which sexual conflict may target. This review concludes with a proposed experiment to determine if sexual conflict is occurring in a group of four genera of mosquitoes. The experiment utilizes the attributes of sexual conflict to differentiate between other processes. A major component is the consequence of mating systems on selective processes to determine if sexual conflict is involved in the evolution of male accessory gland proteins.

Doctor of Philosophy / Department of Entomology / Alberto B. Broce / Ludek Zurek / Stable flies, Stomoxys calcitrans (L.), are a serious pest to beef cattle in confined animal feeding operations (CAFOs) by causing economic losses in the form of reduced feed intake and feed efficiency, resulting in reduced weight gain. Integration of sanitation, parasitoids, and residual insecticides offers a much-needed reduction of this pest's impact on CAFOs. In the past two decades, stable flies have become the most important pest of pastured cattle. Further impact that stable flies have on cattle is when cattle seek protection from stable flies by standing in water, which results in water pollution with fecal matter, in addition to reduced foraging time. Sites of winter feeding of round hay bales have demonstrated to be important habitats for stable fly development during spring/summer. Cattle feeding on round bales can waste as much as 40% of the total amount of hay when fed in conventional ring feeders. Hay wastage is largely a function of the type of feeding method and the amount of agonistic behavior of the cattle. Feeding methods range from rolling hay directly onto the ground to the use of various types of feeders. Since traditional control methods utilized in CAFOs against stable flies have not been evaluated in pastures, producers rely heavily on organic insecticides in efforts to control this pest. At this time, there are no effective control methods available for stable fly management on pastured cattle. This research examined different management strategies that could minimize or eliminate stable fly larval habitats by reducing the amount of hay wasted being mixed with manure. In addition, different hay and manure mixtures were compared to characterize the larval habitat at these hay-feeding sites. Finally, the efficacy of boric acid, Metarhizium anisopliae, and tetrachlorvinphos in controlling the development of stable flies in hay substrates was evaluated.