Social organization is generally assumed to increase colony efficiency and survival; however, little quantitative information is available to support this assumption. Polymorphism is an important aspect of labor division in colonies of the fire ant, Solenopsis invicta. Our objective was to investigate the effect of fire ant polymorphism on brood production efficiency. / We set up standardized polymorphic colonies with a full range of worker sizes and artificial monomorphic colonies that contained only small, medium or large workers respectively. Polymorphic colonies produced brood at about the same rate as colonies composed of only small workers. Colonies composed of only medium workers produced about half as much brood, and colonies composed of only large workers produced little or no brood at all. This pattern was independent of colony size; however, smaller colonies (0.75 g) produced almost twice as much brood per gram of workers as larger colonies (3.0 g). Additional experiments revealed that the size of workers in the artificial monomorphic colonies affected all stages of brood rearing. Large workers not only inhibited the development of early and late instar larvae but also reduced the queen's oviposition rate. / Energetic brood production efficiency was determined by dividing the grams of brood produced per unit time by the energetic costs expended for the maintenance and production of each worker size class. Worker maintenance costs were estimated from respiration, while production costs were determined from the caloric content of worker tissue divided by their average longevity. Worker respiration per milligram body weight decreased about 40% as body size increased. Large workers lived about 50% longer than small workers and contained 7% more energy per milligram of tissue. Energetic efficiency in polymorphic colonies was approximately 10% higher than in colonies composed of only small workers. In other words, when food supplies are limiting, polymorphism may offer a slight advantage in brood production. / Source: Dissertation Abstracts International, Volume: 45-02, Section: B, page: 0452. / Thesis (Ph.D.)--The Florida State University, 1984.

Seasonal fluctuations of benthic macrofauna (> 500 (mu)m) in the oligohaline East Bay region of the Apalachicola estuary were examined. Multivariate analyses of long-term (42 - 72 months) data from five soft-bottom stations identified three physico-chemical variables (river flow, water temperature and salinity) that were correlated with abundances of dominant macrofaunal species (six polychaetes and one amphipod). However, among station inconsistencies in the responses of these species to environmental variables suggested that additional factors, such as biotic interactions, are important. / Macrofaunal densities peaked during winter months, followed by a rapid decline during late winter/spring. Minimum densities occurred during the summer. The spring decline coincided with an influx of bottom-feeding fishes (Leiostomus xanthurus and Micropogonias undulatus). To test the hypothesis that these fishes were responsible for macrofaunal reduction, predator exclusion experiments were conducted at two unvegetated shallow subtidal East Bay stations. A preliminary study was conducted to design cages (mesh size = 6mm) that produced minimal physical and chemical artifacts. These were used with two-sided controls and uncaged controls in short-term (two month) exclusion experiments to test the effects of bottom-feeding fishes in the spring and Penaeus setiferus in the fall. During 1980, large motile predators were not important in regulating the densities of most macrofaunal species. Densities of L. xanthurus and P. setiferus were lower than in previous years. Despite reduced abundance of bottom-feeding fishes, macrofaunal densities still declined during late winter/spring. Three polychaetes, Mediomastus ambiseta, Streblospio benedicti and Hobsonia florida, accounted for a considerable portion of the late winter reduction in density. Recruitment data from defaunated sediments revealed a low abundance of H. florida and S. benedicti larvae, and virtually no M. ambiseta larvae, in the spring. Thus, lack of larval recruitment contributed to the decline of these short-lived species. It is postulated that increased river flow and lowered salinities during late winter/spring may contribute to the decline of macrofaunal densities by reducing larval recruitment. / Source: Dissertation Abstracts International, Volume: 43-06, Section: B, page: 1723. / Thesis (Ph.D.)--The Florida State University, 1982.

A thirteen month study was conducted in the coastal grassbeds of Apalachee Bay, Florida, to assess the influence of macrophyte species composition and biomass on distribution patterns of plant-associated crustacean assemblages. Crustaceans were collected from a variety of macrophyte-related habitats, including shoots of the seagrasses Thalassia testudinum and Halodule wrightii, large and small bare areas among grass shoots and several macroalgal species with differing morphologies. / Abundance per gram dry weight of Thalassia, species richness and composition of Thalassia-associated crustaceans were similar between sampling sites, yet individuals/m('2) varied significantly. A strong positive correlation was observed between crustacean density and above-ground Thalassia biomass. Comparison of seasonal patterns in faunal abundance between sites suggested differences in crustacean numbers were influenced by plant standing crop, timing of major reproductive effort and seagrass-mediated predation. / Within-site faunal comparison of bare areas and two seagrasses indicated that crustacean abundance and species richness were similar between vegetated substrata and were significantly higher than unvegetated microhabitats. Animals densities, as well as the proportion of epifauna, increased with increasing plant biomass. Generally, crustacean species composition was similar among microhabitats, while differences were noted in relative abundances of certain species. / Significant differences in abundance per gram dry weight were observed among macroalgal species with the highly complex leafy and foliose forms hosting greatest numbers of individuals. Crustacean species richness and composition were similar among algae yet differences were found in the relative abundances of species. Significant abundance-plant weight, species-plant weight and species-abundance relationships were observed for macroalgal crustaceans. Abundance explained most of the variation in species number with plant weight contributing only a small but significant amount. Although macroalgae hosted greater abundances per gram dry plant weight than Thalassia, the relative contribution of macroalgal crustaceans to total faunal density was small and dependent upon the biomass of algae within the grassbeds. / Source: Dissertation Abstracts International, Volume: 43-09, Section: B, page: 2792. / Thesis (Ph.D.)--The Florida State University, 1982.

Using an experimental approach, I have elucidated the role of competition among Heliconiinae larvae in Puerto Rico. I used field cages to control predators and parasitoids while otherwise simulating natural conditions. By vegetatively reproducing Passiflora, I controlled for secondary compounds and other genetically influenced traits. To detect negative interactions I measured pupal weights and larval survivorship. Weight is highly correlated with wing length, with no sexual dimorphism for weight. Larval density and food quantity manipulations demonstrated that six or more individuals of Heliconius charitonius L. or Dryas julia Fab. intraspecifically compete when restricted to 600 cm('2) or less of food plant. Interspecific competition occurred at a density of six of each species. Larval development of H. charitonius is faster with a mean of 13.5 days while D. julia takes 21.5 days; consequently, in my cages, H. charitonius was the superior competitor. / One year of observation at two climatically distinct forests, Guanica (dry) and Cambalache (wet), shows variations in the relative density and distribution of heliconians and Passiflora. Guanica's distinct precipitation-induced seasonality is affected by unpredictable tropical storms; consequently abiotic factors are significant determinants of heliconian distribution and abundance. At Guanica, Passifloras are conspicuously clumped while at Cambalache, their densities are higher. Resource partitioning of new and old plant parts was observed only at Cambalache Forest; otherwise no habitat or plant species partitioning was observed. Although 72% of ovipositing females select large enough plants for their larvae to complete development at Cambalache, only 30% did so at Guanica. Even though observed predation and parasitism were low, disappearance of immatures was high, around 65%. / Comparing experimental results to field observations, I found no interspecific competition and insignificant intraspecific competition at Cambalache. At Guanica, where larvae depend on new growth, which occurs in distinct pulses, intra- and interspecific competition occurred in 38% of the observed plants. However, since adults are patchily distributed, island-wide competitive exclusion of any of the species is unlikely. / Source: Dissertation Abstracts International, Volume: 44-06, Section: B, page: 1708. / Thesis (Ph.D.)--The Florida State University, 1983.

I used approximatley 10,000 records from the North American Nest Record Card Program, over 2000 records from the Western Foundation of Vertebrate Zoology, and nearly 1000 records from Canadian sources to obtain data on the phenology of the nesting season and clutch size of a widespread altricial bird, the Red-winged Blackbird (Agelaius phoeniceus L.). I assess the compatability of nest record cards and clutch collection slips, for estimating nesting phenology and clutch size for the redwing and give suggestions for improving nest record. / My approach to the study of geographic variation in clutch size has been to use large data sets to map patterns of variation in life history traits, look at the relationship of single variables as predictors of clutch size, and then use all variables in a multiple regression model. I examine four hypotheses that have been proposed to account for geographic variation in clutch size: daylength, density-dependent food limitation, food availability independent of density, and the "eggs-in-one-basket" hypothesis. The variables used to predict clutch size were latitude, longitude, length of the breeding season, intraspecific local abundance, and 5 climatic variables. / Clutch size of the redwing varies in a complex pattern in North America. Mean clutch size ranges from 2.77 in Costa Rica to 4.30 in Alaska. The daylength hypothesis is generally supported, because latitude is the most important predictor in the multiple regression model. However, clutch size also varies from east to west. The density-dependent food limitation hypothesis is not supported because local abundance is not a good predictor of mean clutch size and annual migration is not taken into account. The "eggs-in-one-basket" hypothesis is not strongly supported because redwings have multiple broods at high and middle latitudes. However, the length of the breeding season is retained as a predictor variable in the most conservative multiple regression model. My results are most consistent with the hypothesis that geographic variation in clutch size is related to large-scale patterns of variation in food availability. / Source: Dissertation Abstracts International, Volume: 47-07, Section: B, page: 2739. / Thesis (Ph.D.)--The Florida State University, 1986.

I studied factors affecting recruitment of the gorgonian Leptogorgia virgulata and the compound ascidian Aplidium stellatum onto a subtidal limestone outcropping. The recruitment of L. virgulata was significantly reduced by the presence of sand. The relative abundance of animals that recruited into three experimental treatments did not vary over a one year period. Transplant experiments showed that buried colonies grow rapidly, raising new polyps out of the sand. The experimental results successfully predicted the spatial pattern of L. virgulata recruitment on natural surfaces. Other experiments showed that recruitment is significantly reduced by the presence of benthic algae, but is not affected by the exclusion of large fish predators or the removal of established adult colonies. The results emphasize the importance of microhabitat variation in controlling the spatial pattern of recruitment. / Microhabitat also affected recruitment of the compound ascidian Aplidium stellatum. Almost half of the recruits appeared on vertical surfaces, which are rare in the field. In the lab, larvae settled on vertical surfaces with a two to one preference, regardless of how much vertical surface was offered in a particular treatment. However, this preference was too weak to solely account for the field pattern, suggesting differential mortality of newly-settled animals on horizontal surfaces. Temporal patterns of recruitment were associated with the presence of larvae in mature colonies. The presence of larvae correlated with egg numbers and water temperature. / Source: Dissertation Abstracts International, Volume: 47-01, Section: B, page: 0049. / Thesis (Ph.D.)--The Florida State University, 1985.

Source: Dissertation Abstracts International, Volume: 40-09, Section: B, page: 4103. / Thesis (Ph.D.)--The Florida State University, 1979.

Source: Dissertation Abstracts International, Volume: 40-09, Section: B, page: 4105. / Thesis (Ph.D.)--The Florida State University, 1979.

In Chapter I, I tested Opler's (1978) hypothesis regarding leaf miners that feed on oaks with different leaf persistence times by monitoring abundances and species richness of leaf miners on three species of oaks, Quercus falcata, Q. nigra, and Q. hemisphaerica (Fagaceae). No significant differences among oak species was found for either densities or species richness of leaf miners. Moreover, my results show that leaf-mining densities are negatively and significantly correlated with nitrogen content, suggesting the leaf miners may not be sensitive (in terms of population sizes) to seasonal decreases in nitrogen content of oak leaves. / In Chapter II, to test for spatial and temporal differences in mortality factors and survivorship, I experimentally isolated oak trees by transplanting them into agricultural fields. Parasitism by hymenopterans significantly decreases for leaf miners on isolated trees, thus increasing larval survivorship. However, increased survivorship does not result in higher abundances in subsequent generations because on at least small trees, leaf-mining populations are maintained by continual re-immigration with little or no in situ reproduction and colonization. / In Chapter III, five species of oaks were fully enclosed with fine mesh screening or the leaf litter beneath the tree was covered with a plastic cage to test for the contribution of in situ and long range colonization respectively by leaf miners to small trees. My results indicate that both population sizes and species richness of leaf miners are maintained on small trees primarily by long range colonization and little or no in situ colonization and reproduction occurs. This suggests that it may be incorrect to consider leaf-mining populations on small trees as in dynamic equilibrium because they represent mostly transient individuals and do not sustain breeding populations. / In Chapter IV, densities of a leaf miner, Cameraria sp. nov., are experimentally increased on an enclosed oak tree. Even though densities are significantly higher on the caged tree as compared to a control, I find no evidence for intraspecific competition. Instead, survivorship of larval leaf miners increased on the caged tree. These results suggest that parasitism, and possibly predation, regulate population densities of this leaf miner below which competition would usually occur. / In Chapter V, terrestrial invertebrate predators were excluded from oak trees to determine if they are a significant mortality factor for a species of leaf-mining insect, Eriocraniella sp. nov. Larval survivorship was significantly higher and predation lower on trees that had gound-dwelling invertebrate predators excluded. / In Chapter VI, I ascertained whether oak leaves that were mined abscised earlier than undamaged leaves by collecting and examining leaves in leaf baskets placed beneath oak trees. My results indicate that significantly more mined leaves abscise earlier than unmined ones and that propensity of mined leaves to fall depends on size of the oak leaf and phenology of the particular oak species. Life table analysis of two leaf miners, Tischeria purinosella and Brachys ovatus, show that early leaf abscission is an important mortality factor for larval leaf miners. / Source: Dissertation Abstracts International, Volume: 41-05, Section: B, page: 1631. / Thesis (Ph.D.)--The Florida State University, 1980.

Source: Dissertation Abstracts International, Volume: 41-01, Section: B, page: 0054. / Thesis (Ph.D.)--The Florida State University, 1979.