Thesis (M.S.)--Oregon State University, 1995. / Typescript (photocopy). Includes bibliographical references (leaves 94-100). Also available on the World Wide Web.

Thesis (M.S.)--University of Delaware, 2008. / Principal faculty advisor: Douglas W. Tallamy, Dept. of Entomology & Wildlife Ecology. Includes bibliographical references.

Thesis (M.S.)--Humboldt State University, 2010. / Includes bibliographical references (leaves 59-60). Also available via Humboldt Digital Scholar.

Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 58-62). Also available on the World Wide Web.

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Parent-offspring communication is widely regarded as having evolved to provide the parent with honest information about the hunger state of its offspring, thus enabling it to mediate conflict over resource allocation between parents and offspring. The conflict is caused by the offspring benefitting from receiving more care than the parents are selected to provide due to the costliness of care. I studied the role of parent-offspring communication as a mediator for the conflict in the burying beetle Nicrophorus vespilloides. The burying beetle is an excellent study system for this question, as the larvae, that are raised on carcasses of small vertebrates and cared for by both the male and the female beetle, beg for food from their parents with highly distinguishable begging displays. First, I examined whether offspring adjusted their begging to different classes, or individual adult beetles. I found that while the larvae did not discriminate between male and female beetles, they adjusted their care to cues indicating individual recognition of adults. Second, I tested whether begging was based on offspring size at egg stage, and found no indication that offspring adjusted their begging to improve their innate quality. Third, I examined whether parental response to begging exhibits behavioural plasticity when the internal clock for the timing of reproduction for the parent, and the demand from the larvae do not meet. I found that the parents adjusted their care based on the amount of begging exhibited by the larvae. Fourth, I investigated whether parental adjustment of care based on offspring begging incurs a reproductive cost to them. I found that the females paid a cost in fecundity, but not in the number of dispersing larvae or their own survival. My original contribution to knowledge is therefore to show through these four studies, that offspring begging is adjusted based on parental cues, and can directly affect proximate parental behaviours, and also incurs a reproductive cost to their future reproductive success, thus providing more experimental evidence for the importance of parent-offspring communication, and its implications to the evolution of parental care.

Bark beetles are major pests of pine forests in North America that can inflict considerable damage and cause severe economic loss. The checkered beetle Thanasimus dubius Fabricius (Coleoptera: Cleridae), an abundant predator in the Eastern USA and Canada, has been suggested to influence the dynamics of several bark beetles, including the economically important southern pine beetle (SPB), Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae). Because of the importance of T. dubius in pine forests, I studied several aspects of T. dubius biology including both its chemical and dispersal ecology. I first present an experiment that was conducted to improve the rearing system of T. dubius so that sufficient numbers of predators could be produced more efficiently for both behavioral and ecological studies. Improvements to the rearing method potentially could be achieved by adding a preservative to increase the shelf-life of the diet used to feed larval T. dubius thereby allowing feeding intervals to be extended. To evaluate this, I added sorbic acid, a preservative, to the larval diet at three different concentrations (0, 0.1 and 0.2%) and for two different intervals between feedings (2-3 vs. 5 days). Additionally, I measured potential deleterious effects of this preservative on predator performance (i.e., female fecundity). I then assessed the effect of this predator on SPB survival by releasing newly hatched T. dubius larvae at several densities (0, 50 100, and 200) on pine logs infested by SPB. I also studied the chemotactic response of this predator toward various volatiles such as prey pheromones or tree volatiles in a wind tunnel. I developed a method that associated upwind flight behavior and antennal behavior to quantify the relative attractiveness of each tested source of chemical. I then conducted three experiments to investigate the ability of individual T. dubius to respond to different prey olfactory signals (bark beetle pheromones) and assess their potential for learning. First, I examined individual predator preferences toward three major prey pheromones (ipsenol, ipsdienol, and frontalin) in a study that combined a mark-release-recapture experiment with a field choice test. I also measured the responses of individual wild T. dubius in a wind tunnel, which allowed the testing of a wider range of semiochemicals (frontalin, ipsenol, ipsdienol, sulcatol, and α-pinene). A final wind tunnel experiment tested the ability of naive predators to learn two prey pheromones, frontalin and ipsenol, that were presented alone or associated with a reward. In the last chapter, I quantified the dispersal of this predator and its behavior along an edge separating a pine forest from a non-suitable habitat. I analyzed T. dubius distribution and movement in the field relative to its bark beetle prey Ips grandicollis Eichhoff (Coleoptera: Curculionidae) and to the root feeder Dendroctonus valens LeConte (Coleoptera: Curculionidae). These three insects are associated with the phenomenon of red pine decline in the Great Lakes area. Thus, understanding the relative pattern of movements of these three beetles could provide considerable knowledge on the spatial and temporal progression of red pine decline by, for instance, assessing the connection between existing pockets. I estimated the dispersal quantiles for this predator relative to its bark beetle prey and determined whether dispersal behavior was relatively homogeneous (one kind of disperser) or heterogeneous (two kinds). In a second part, I sampled the abundance of T. dubius, I. grandicollis, and D. valens along transects set between a matrix area constituted by a clearing and a habitat zone composed of red pine forest. I further developed a diffusion model, including a constant k (corresponds to the ratio of densities along the edge), that permits characterization of beetle behavior around the boundary. Studies developed in the present dissertation, therefore, investigated several aspects of T. dubius ecology: predation on SPB, ability to respond to an olfactory signal, and dispersal traits. I first showed that augmentation with larval T. dubius can successfully reduce the SPB ratio of increase in infested pine logs. I also developed a system of rearing T. dubius that was more efficient and could allow larger numbers of predators to be produced. Sorbic acid did not reduce adult lifetime or size but did affect female fecundity (20 - 40% reduction). Increasing feeding time interval to 5 days (instead of 2-3 days) improved the efficiency of the system, even when sorbic acid was not added in the diet. Wind tunnel experiments present a methodology that could enable future quantification of the relative attractiveness of various semiochemical treatments. I identified a particular antennal behavior, which I called "stand up antennal" that was typically produced when the insect was attracted to a semiochemical. The choice tests in the field and the wind tunnel experiment using wild adults both showed that T. dubius individuals are generalists that are flexible in their response to a broad range of semiochemical signals (frontalin, ipsenol, ipsdienol, sulcatol, and α-pinene). I demonstrate that naive predators are more attracted toward ipsenol after having experienced conditioning with this kairomone via a reward. Finally, experiments on dispersal and edge behavior revealed that T. dubius and one of its common prey, the bark beetle I. grandicollis, exhibit a different pattern of movement within red pine stands and surrounding habitats. First, adult T. dubius can disperse substantially further (50% dispersed beyond 1.54 km) than I. grandicollis adults (50% dispersed beyond 0.13 km). Second, T. dubius was highly affected by the presence of an edge, showing a step-like pattern with very predators caught in unsuitable areas. Conversely, the behavior of I. grandicollis was less limited by such a boundary. As with T. dubius, the root colonizer D. valens showed a strong edge behavior that was characterized by avoiding matrix zones.

In this thesis, I investigated the role of parental care in evolution. Parents provide the environment in which offspring develop and therefore have a large influence on their offspring's phenotypes, and so are in prime position to influence evolutionary processes. I used an experimental approach, and focused on the burying beetle, Nicrophorus vespilloides. The burying beetle is a perfect system for this question: they exhibit elaborate biparental care which is correlated with rapid speciation in the Nicrophorus genus. I started with a thorough exploration of burying beetle ecology and how the guild structure and interspecific competition in local populations can shape phenotypic evolution of my focal species, N. vespilloides. Interspecific competition shapes how the carrion niche is partitioned, which feeds back onto the evolution of body size within Nicrophorus reducing competition. The evolution of parental care in this genus likely facilitated its adaptive radiation, as parental care is linked with body size, both within and across species. But to what extent does the ecology shape the production and maintenance of phenotypic and genetic variation? I then use a quantitative genetic approach to show that body size and development time of N. vespilloides shows no additive genetic variation. Evolution of these fitness related traits can only occur through maternal effects or sibling effects. I tested this prediction by mimicking the radiation of the burying beetles by imposing my own selection on body size when parents could care for their offspring and when they could not. The presence of post-hatching parental care dramatically changed how populations responded to selection, through a combination of cooperation between parents and offspring, and cooperation between offspring. As well as shaping the evolutionary potential of populations, an experimental change in parental care can induce new selective forces, favouring adaptive novelties for the new social environment. Larvae evolving without parental care evolved disproportionately larger mandibles when small to better adapt them to a life without care. Much is known about the evolution of parental care across the animal kingdom, but what happens next: are the burying beetles a "one-off"? I compiled data across the arthropods comparing clades that exhibit post-hatching parental care with their sister clades and show that clades with care are more species rich. While the mechanism may not be the same as with Nicrophorus, I discussed other potential mechanisms that may be at play in the role of parents in evolution.

Orientador: Júlio César Galli / Banca: Arlindo Leal Boiça Júnior / Banca: Valter Arthur / Resumo: O presente trabalho objetivou conhecer a flutuação populacional de moscas-das-frutas (Anastrepha spp. e Ceratitis capitata) e de Triozoida limbata, o efeito do suco açucarado de goiaba e de diferentes concentrações de Moscatex® como atrativo alimentar de tefritídeos, e a evolução do dano de Costalimaita ferruginea e Triozoida limbata em um pomar de goiaba em Jaboticabal/SP. Para o estudo da flutuação populacional das moscas-das-frutas e do efeito dos atrativos alimentares foram empregados quinzenalmente, no período de março de 2005 a junho de 2006, frascos caça-moscas, contendo o atrativo alimentar proteína hidrolisada de milho (Moscatex®) nas concentrações de 1%, 2%, 3% e 3% + suco açucarado de goiaba 50%. Para a observação da evolução do dano de T. limbata e de C. ferruginea foram analisadas quinzenalmente 20 plantas do pomar. Para cada planta foram avaliadas 10 folhas contendo o sintoma do ataque da respectiva praga atribuindo-se uma nota de 1 a 4 de acordo com a porcentagem de dano. Os picos populacionais de Anastrepha spp. observados ocorreram no período frutificação da cultura, sendo mais de 90% dos tefritídeos pertencentes a este gênero. O aumento na concentração de Moscatex®, bem como a adição de suco açucarado de goiaba foi eficiente na captura das moscas-dasfrutas. A densidade populacional do psilídeo aumentou consideravelmente com o surgimento das brotações e apresentou uma correlação positiva com a temperatura. O dano do psilídeo acompanhou a densidade populacional da praga. O dano de C. ferruginea se manteve baixo após a aplicação de inseticida e apresentou uma correlação positiva com a umidade relativa... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present work aimed to know the populational fluctuation of fruit flies (Anastrepha spp. and Ceratitis capitata) and Triozoida limbata; the effect of the sugary juice of guava and different concentrations of Moscatex® as attractive alimentary of tephritids; and the damage evolution of Costalimaita ferruginea and T. limbata in a guava orchard in Jaboticabal - SP. For the study of the populational fluctuation of fruit flies and the effect of alimentary attractive they were used biweekly, in the period of march of 2005 to june of 2006, traps containing the attractive alimentary protein corn hydrolyzed (Moscatex®) in the concentrations of 1%, 2%, 3% and 3% + sugary juice of guava 50%. For the observation of evolution of the damage of T. limbata and C. ferruginea were analyzed 20 plants of the guava orchard biweekly. For each plant they were appraised 10 leaves containing the symptom of the attack of the respective pest being attributed a note from 1 to 4 in agreement with the damage percentage. The population picks of Anastrepha spp. observed they happened in the period fruitage of the culture, being more than 90% of the tephritids belonging to this gender. The increase in the concentration of Moscatex®, as well as the addition of sugary juice of guava showed efficient in the capture of the fruit flies. The population density of T. limbata increased considerably with the appearance of the sprout and it presented a positive correlation with the temperature. The level of damage of T. limbata accompanied the populational density of the pest. The level of damage of C. ferruginea stayed low after the insecticide application and it presented a positive correlation with the relative humidity... (Complete abstract, click electronic access below) / Mestre

A method of linking SORTIE-ND and PrognosisBC was developed for the purpose of predicting natural regeneration and forecasting future stand conditions in mountain pine beetle (Dendroctonus ponderosae Hopkins - MPB) attacked stands in the Interior Douglas-fir (IDF) and Sub-Boreal Spruce (SBS) biogeoclimatic ecosystem zones of central and southeastern British Columbia. PrognosisBC, a spatially-implicit growth model, lacked a submodel suitable for predicting natural regeneration in unsalvaged MPB-disturbed stands. To fill this gap, estimates of regeneration (trees <7.5 cm diameter at breast height - DBH) were supplied to PrognosisBC using the light-mediated forest dynamics model SORTIE-ND and the linked model was used to forecast future stand conditions. In order to improve results, a density-dependent system of crown allometry equations to predict crown depth and crown radius was developed and then added to SORTIE-ND. The equations used stand-level measures of stems ha-¹, basal area (m² ha-¹), and the basal area of trees taller than the target tree to explicitly account of the effects of crowding on the crown axes. Additionally, crown radius and crown depth were used as dependent regressors. The equations were fit using a nonlinear three-stage least squares estimator and generally provided good estimates of crown depth and crown radius for lodgepole pine (Pinus contorta var. latifolia), hybrid spruce (Picea engelmannii x glauca (Moench) Voss), Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and trembling aspen (Populus tremuloides Michx.). Tests of the hybrid model with the improved system of crown allometry equations were performed using reconstructed plot data collected from natural stands disturbed by MPB 25-years ago. The hybrid model provided good estimates (small mean bias and low root mean square error) for the basal area of advance regeneration (2 < DBH < 7.5 cm) for lodgepole pine (Pinus contorta var. latifolia). The best estimates were achieved when trees <7.5 cm DBH were transferred from SORTIE-ND to PrognosisBC 15-years after MPB-disturbance. For trees <2 m in height, poor estimates of stems ha-¹ where obtained. Despite the shortcomings with respect to trees <2 m tall, the results suggest that linking SORTIE-ND and PrognosisBC is an effective method of building a hybrid model capable of being used in MPB-disturbed forests. However, full parameterization of the SORTIE-ND model is likely needed to obtain accurate estimates for all sizes of natural regeneration. / Forestry, Faculty of / Graduate