Aspects of the behavior, biology, and economic importance of carpenter ants were examined. The overall objectives of this study were to determine the economic importance of carpenter ants, and to extend the data currently available on two of the most common and economically important species in the U.S. A survey for the economic importance of carpenter ants indicated that carpenter ants are considered a serious pest by homeowners. The results show that 90% of the homeowners who requested control for carpenter ants during 1980, paid more than $25 for carpenter ant control. The presence of detectable damage was not the definitive factor in the decision to request control. Camponotus ferrugineus and C. pennsylvanicus are similar in their colony foundation and biology. C. ferrugineus required 54 days to produce the first brood and there were 18 workers, including one intermediate worker, in the first brood. Queens of C. pennsylvanicus required an average of 46 days to rear the first brood. Ad libitum feeding did not have a significant effect on colony founding in C. pennsylvanicus. Two queens reared their first brood under artificial light. Food preference studies of C. pennsylvanicus and C. ferrugineus indicated that these two species have similar food preferences. Although honey was preferred to most foods tested, it may not supply sufficient nutrients to ensure proper colony nutrition. C. pennsylvanicus has become well adapted to man-made structures. Some foraging ants are present year round. C. pennsylvanicus optimizes its foraging by exploiting indoor and outdoor foraging sites. The division of labor during nest construction may be based on subcaste. Major workers appear to be responsible for most nest-building in mature colonies. / Master of Science

Overwintering nests of C. pennsylvanicus were dissected and censused. All castes were assayed for glycerol and for changes in nutrient reserves. Spring queens were collected at swarming and allowed to initiate nests. Queens were analyzed for nutrient reserves during the early stages of nest founding. Overwintering nests contained large proportions of larvae and alates. Physical associations within the winter nest were evident between majors and alates, and between larvae and the queen; minors were associated with larvae to a lesser degree. Reproductives and larvae were negatively correlated, and worker caste ratios shifted according to whether an area was dominated by larvae or alates. Winter nest temperatures followed ambient temperatures, though fluctuations were less extreme. Glycerol was detectable in all castes and stages. Major and minor workers were similar in nutrient content. Lipid and protein contributed greater than 80% of dry weight, glycogen less than 20%, and free sugars less than 10%. Lipid was progressively depleted through winter. Majors lost most protein and dry weight between November and January, minors between February and April. Glycogen changes emulated mean ambient temperature patterns. Overwintering gynes possessed large reserves of lipid, up to approximately 62% in mid-winter. Glycogen levels rose and fell with mean ambient temperatures. Most nutrient reserves in founding queens were depleted from the head/thorax region between swarming and first larval emergence; between larval emergence and first worker eclosion, significant losses occurred only in the gaster. Protein alone increased significantly in the gaster prior to larval emergence, after which it was depleted. / Master of Science

So, Wai Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 244-270). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.vi / Table of contents --- p.viii / List of figures --- p.xii / List of tables --- p.xiv / List of plates --- p.xvii / List of appendices --- p.xviii / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter 1.1 --- General Information of Hong Kong Climate and Vegetation --- p.1 / Chapter 1.1.1 --- Grasslands in Hong Kong --- p.3 / Chapter 1.1.2 --- Shrublands in Hong Kong --- p.4 / Chapter 1.1.3 --- Woodlands in Hong Kong --- p.5 / Chapter 1.1.4 --- Plantations in Hong Kong --- p.7 / Chapter 1.2 --- Quarries and Landfills in Hong Kong --- p.9 / Chapter 1.2.1 --- Quarries in Hong Kong --- p.9 / Chapter 1.2.2 --- Landfills in Hong Kong --- p.13 / Chapter 1.3 --- Ants as Bioindicators --- p.16 / Chapter 1.3.1 --- The Use of Bioindicators --- p.16 / Chapter 1.3.2 --- The Use of Ants as Bioindicators --- p.19 / Chapter 1.3.3 --- Ant Functional Groups --- p.21 / Chapter 1.3.4 --- Ants in Hong Kong --- p.22 / Chapter 1.4 --- Research Objectives --- p.24 / Chapter Chapter 2 --- Ant Communities in Natural and Semi-natural Habitats in Hong Kong --- p.25 / Chapter 2.1 --- Introduction --- p.25 / Chapter 2.1.1 --- Abiotic Factors --- p.25 / Chapter 2.1.1.1 --- Habitat complexity --- p.25 / Chapter 2.1.1.2 --- Elevation --- p.26 / Chapter 2.1.1.3 --- Soil properties --- p.27 / Chapter 2.1.2 --- Biotic Factors --- p.30 / Chapter 2.1.2.1 --- Interaction with plants --- p.30 / Chapter 2.1.2.2 --- Interaction among ants --- p.31 / Chapter 2.1.2.3 --- Interaction with other fauna --- p.32 / Chapter 2.1.3 --- Objectives --- p.33 / Chapter 2.2 --- Materials and Methods --- p.34 / Chapter 2.2.1 --- Study Sites --- p.34 / Chapter 2.2.2 --- Ant Sampling --- p.41 / Chapter 2.2.2.1 --- Pitfall trapping --- p.42 / Chapter 2.2.2.2 --- Litter extraction --- p.43 / Chapter 2.2.2.3 --- Visual search --- p.44 / Chapter 2.2.2.4 --- Baiting --- p.45 / Chapter 2.2.3 --- Ant Examination --- p.46 / Chapter 2.2.4 --- Other Samplings --- p.46 / Chapter 2.2.4.1 --- Soil sampling --- p.46 / Chapter 2.2.4.2 --- Vegetation measurements --- p.47 / Chapter 2.2.5 --- Data Analysis --- p.47 / Chapter 2.3 --- Results --- p.50 / Chapter 2.3.1 --- Vegetation and Soil Properties --- p.50 / Chapter 2.3.2 --- "Species Diversity, Abundance and Frequency of Occurrence" --- p.63 / Chapter 2.3.3 --- Ant Community --- p.72 / Chapter 2.3.4 --- Ant Species Analysis --- p.75 / Chapter 2.3.5 --- Functional Group Analysis --- p.78 / Chapter 2.3.6 --- Correlation of Ant Community with Vegetation and Soil Properties --- p.81 / Chapter 2.4 --- Discussion --- p.84 / Chapter 2.4.1 --- Ant Species Richness in Different Habitats --- p.84 / Chapter 2.4.2 --- Relationship of Ant Community and Vegetation and Soil Properties --- p.89 / Chapter 2.4.3 --- Indicator Species --- p.91 / Chapter 2.4.4 --- Changes in Community Structure --- p.92 / Chapter 2.4.5 --- Ant Functional Groups --- p.93 / Chapter 2.5 --- Conclusions --- p.95 / Chapter Chapter 3 --- Ant Community on Rehabilitated Lands in Hong Kong --- p.97 / Chapter 3.1 --- Introduction --- p.97 / Chapter 3.1.1 --- "Restoration, Rehabilitation and Reallocation" --- p.97 / Chapter 3.1.1.1 --- Restoration --- p.97 / Chapter 3.1.1.2 --- Rehabilitation --- p.97 / Chapter 3.1.1.3 --- Reallocation --- p.98 / Chapter 3.1.2 --- Ants as Biodiversity Indicators and Ecological Indicators of Disturbed Lands --- p.99 / Chapter 3.1.3 --- Factors Affecting Ant Community Structure on Rehabilitated Lands during Succession --- p.102 / Chapter 3.1.3.1 --- Dominance-controlled and founder-controlled model --- p.103 / Chapter 3.1.3.2 --- Time since last disturbance --- p.104 / Chapter 3.1.3.3 --- Proximity to undisturbed sites --- p.104 / Chapter 3.1.3.4 --- Habitat created --- p.105 / Chapter 3.1.3.5 --- Presence of invasive and weed species --- p.105 / Chapter 3.1.4 --- Objectives --- p.106 / Chapter 3.2 --- Materials and Methods --- p.107 / Chapter 3.2.1 --- Study Sites --- p.107 / Chapter 3.2.2 --- Ant Sampling --- p.111 / Chapter 3.2.3 --- Other Samplings --- p.116 / Chapter 3.2.3.1 --- Soil sampling --- p.116 / Chapter 3.2.3.2 --- Vegetation measurements --- p.116 / Chapter 3.2.4 --- Data Analysis --- p.116 / Chapter 3.3 --- Results --- p.119 / Chapter 3.3.1 --- Vegetation and Soil Properties --- p.119 / Chapter 3.3.2 --- "Species Diversity, Abundance and Frequency of Occurrence" --- p.140 / Chapter 3.3.3 --- Ant Community --- p.153 / Chapter 3.3.4 --- Ant Species Analysis --- p.159 / Chapter 3.3.5 --- Functional Groups --- p.161 / Chapter 3.3.6 --- "Correlation of Ant Communities with Vegetation, Soil Properties and Rehabilitation Age" --- p.162 / Chapter 3.4 --- Discussion --- p.167 / Chapter 3.4.1 --- Patterns of Ant Richness on Rehabilitated Quarries and Landfills --- p.169 / Chapter 3.4.2 --- Ant Communities on Rehabilitated Quarries and Landfills --- p.173 / Chapter 3.4.3 --- Species Analysis --- p.176 / Chapter 3.4.4 --- Functional Groups --- p.177 / Chapter 3.5 --- Conclusions --- p.178 / Chapter Chapter 4 --- Ant Community Study-A Cost Effectiveness Analysis --- p.180 / Chapter 4.1 --- Introduction --- p.180 / Chapter 4.1.1 --- Ant Sampling Methods --- p.181 / Chapter 4.1.1.1 --- Pitfall trapping --- p.181 / Chapter 4.1.1.2 --- Litter extraction by Winkler sack or Berlese funnel --- p.183 / Chapter 4.1.1.3 --- Baiting --- p.184 / Chapter 4.1.1.4 --- Direct sampling/Visual search --- p.185 / Chapter 4.1.2 --- Increasing the Cost Effectiveness of Inventory --- p.185 / Chapter 4.1.2.1 --- Simplifying ant identification --- p.186 / Chapter 4.1.2.2 --- Other simplification methods --- p.187 / Chapter 4.1.3 --- Objectives --- p.188 / Chapter 4.2 --- Materials and Methods --- p.188 / Chapter 4.2.1 --- Study Sites --- p.188 / Chapter 4.2.2 --- Ant Sampling --- p.189 / Chapter 4.2.2.1 --- Pitfall trapping --- p.190 / Chapter 4.2.2.2 --- Litter extraction --- p.190 / Chapter 4.2.2.3 --- Visual search (direct sampling) --- p.191 / Chapter 4.2.2.4 --- Baiting --- p.191 / Chapter 4.2.2.5 --- Ant examination --- p.192 / Chapter 4.2.3 --- Data Analysis --- p.192 / Chapter 4.3 --- Results --- p.193 / Chapter 4.3.1 --- Genus and Species Richness --- p.194 / Chapter 4.3.2 --- Ant Community Structure --- p.204 / Chapter 4.4 --- Discussion --- p.212 / Chapter 4.5 --- Conclusions --- p.224 / Chapter Chapter 5 --- General Conclusions --- p.225 / Chapter 5.1 --- Ant Fauna on Natural Habitats --- p.225 / Chapter 5.2 --- Ant Fauna on Man-made Habitats --- p.227 / Chapter 5.3 --- Simplification of Ant Sampling --- p.229 / Chapter 5.4 --- Ants as Bioindicators --- p.230 / Chapter 5.5 --- Further Studies --- p.232 / Appendices --- p.233 / References --- p.244

The general prevalence of sexual reproduction over asexual reproduction among metazoans testifies to the evolutionary, long-term benefits of genetic recombination. Despite the benefits of genetic recombination under sexual reproduction, asexual organisms sporadically occur throughout the tree of life, and a few asexual lineages persisted over significant evolutionary time without apparent recombination. The study of asexual organisms therefore may provide clues to answer why almost all eukaryotes reproduce via meiosis and syngamy and why asexual eukaryotes are almost always evolutionarily short-lived. Towards understanding the evolution of asexual lineages in the Hymenoptera, I first review the diversity of reproductive systems in the Hymenoptera, introduce the study organism, the fungus-gardening ant Mycocepurus smithii, and discuss my research objectives. Second, I integrate information from reproductive physiology, reproductive morphology, natural history and behavior, to document that that queens of M. smithii are capable of thelytokous parthenogenesis, workers are sterile, and males are absent from the surveyed population. These results suggest that M. smithii might be obligately asexual. To place the origin and maintenance of asexual reproduction in M. smithii in an evolutionary context, I use molecular phylogenetic and population-genetic methods to (i) test if M. smithii reproduces asexually throughout its distribution range; (ii) infer if asexuality evolved once or multiple times; (iii) date the origin of asexual reproduction in M. smithii; and (iv) elucidate the cytogenetic mechanism of thelytokous parthenogenesis. During field collecting for these studies throughout the Neotropics, I discovered a new species of obligate social parasite in the genus Mycocepurus. Social parasites are of great interest to evolutionary biology in order to elucidate mechanisms demonstrating how parasites gained reproductive isolation from their host species in sympatry. I describe this new parasite species, characterize its morphological and behavioral adaptations to the parasitic lifestyle, and discuss the parasite’s life history evolution in the context of social parasitism in fungus-growing ants. The dissertation research integrates population-genetic, phylogenetic, physiological and morphological approaches to advance our understanding of the evolution of reproductive systems and diversity of life-history traits in animals. / text

No abstract available. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

Thesis (M.S.) -- Mississippi State University. Department of Entomology and Plant Pathology. / Title from title screen. Includes bibliographical references.

L’exploitation collective de ressources par les sociétés animales repose sur la coopération et la coordination des membres du groupe. Selon la structure sociale des espèces envisagées, leurs comportements collectifs seront dictés par quelques individus imposant leurs choix ou au contraire impliqueront tous les membres du groupe. Chez la fourmi Tetramorium caespitum, la récolte de nourriture repose à la fois sur le dépôt d’une piste de phéromone chimique commune lors du retour des ouvrières vers le nid et sur le recrutement de groupe de congénères guidés par des individus leaders jusqu’à la source de nourriture. Cette espèce nous donne donc l’opportunité d’étudier un système de recrutement couplant des mécanismes décentralisés à la présence d’individus leaders.<p>Nos observations montrent que le recrutement de groupe est lié à une forte motivation de certaines ouvrières à exploiter une source de nourriture découverte. Lorsqu’elles recrutent un groupe, elles passent peu de temps à l’intérieur du nid mais effectuent un taux élevé de contacts avec leurs congénères, principalement à l’entrée du nid, avant de repartir en direction de la nourriture, suivie par le peloton de fourrageuses. Durant le trajet, si une trajectoire rectiligne et une faible vitesse de déplacement favorisent la probabilité des recrutées d’atteindre la source, la perte de recrutées n’entraîne cependant aucune modification du comportement de la meneuse. Enfin, un suivi individualisé des fourrageuses au cours du recrutement montre que la probabilité d’être observée en tant que leader est répartie de manière homogène entre les individus découvrant la source de nourriture, sans influence du nombre de trajets qu’elles ont déjà effectués.<p>Par ailleurs, nous avons étudié l’influence des leaders sur les choix collectifs de la colonie. Les leaders modulent les caractéristiques du recrutement -­-fréquence des groupes, tailles des groupes-­- en fonction des caractéristiques de la source exploitée. Grâce à un modèle multi-­-agents, nous avons démontré que cette modulation du recrutement permet à la colonie entière de focaliser son effort d’affourragement sur la nourriture la plus avantageuse lorsque plusieurs sources sont disponibles dans l’environnement. Enfin, nous avons développé un modèle mathématique décrivant le couplage du recrutement de groupe et du dépôt d’une piste chimique. Grâce à l’étude des états stationnaires de ce modèle, nous avons démontré que la présence des leaders est un élément indispensable à l’initiation de l’exploitation collective d’une ressource chez T. caespitum. Ainsi, les leaders de groupe permettent d’atteindre plus aisément un nombre seuil d’ouvrières à la source qui soit suffisant pour permettre l’émergence d’une piste chimique commune assurant à elle seule un recrutement de masse. Les résultats de cette thèse placent dans une nouvelle perspective notre vision des phénomènes de leadership chez les insectes sociaux. A l’échelle individuelle, ils mettent en évidence le statut temporaire de ces leaders chez Tetramorium caespitum basé sur leur propre motivation et les conditions locales du recrutement ;à l’échelle collective, ils soulignent le rôle complémentaire et facilitateur des leaders qui vont permettre l’émergence de structures auto-­- organisées impliquant l’ensemble de la fourmilière. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

In the black cotton ecosystem of Laikipia, Kenya, four symbiotic ants coexist at a fine spatial scale on canopies of Senegalia drepanolobium. They exhibit different aggressive behaviours and modify their tree canopies differently. These diverse behaviours were expected to affect the associated canopy arthropod communities. At the Kenya long-term exclosure experiment (KLEE) and its immediate environs at Mpala Research Centre, Laikipia, the insect communities coexisting with each of the four ant species were characterized, and their response to different vertebrate herbivory. Other ant species inhabiting the tree canopies or the ground were surveyed too. Pitfall trapping was used in sampling terrestrial ants, while beating and mist-blowing were used in collecting arboreal insects. Different sampling methods had varying efficacies, revealing the importance of using several methods. There are at least sixteen ant species in this ecosystem, all occurring on the ground, but only ten species on the trees. Terrestrial ant communities in this ecosystem cannot be used as indicators of grazing pressure for range management. A total of 10,145 individual insects were collected from the tree canopies, comprising of 117 species from seven orders and 25 families, forming a complex community of species interacting at different levels. Symbiotic ant species had a significant effect on insect community structure and composition. Crematogaster sjostedti was associated with a community that was significantly different from the other ant species. There was no significant effect of vertebrate feeding pressure on the canopy insect community, but there was an interaction effect between ant species and treatments. Significant differences between ant species mostly occurred on treatment plots where only cows were allowed to graze. One or more of the ant species may be a keystone species in this ecosystem even though experimental manipulations failed to confirm earlier findings. It was concluded that the one-year period during which experimental manipulations were carried out was not long enough to reflect takeover effects on the insect community. The four symbiotic ant species colonizing S. drepanolobium comprises of two guilds, the hemipteran-tending ants (C. sjostedti and Crematogaster mimosae) and non-tending ants (Crematogaster nigriceps and Tetraponera penzigi). Communities associated with these guilds were found to be significantly different in all four diversity indices. The black cotton ecosystem is species-poor compared to other ecosystem such as forests. The number of insect species that colonizes S. drepanolobium and coexists with acacia-ants forms a large proportion of the invertebrate community. Therefore, this ecosystem should be conserved to safeguard this invertebrate community. This will also give scientists a chance to establish how the various insect species coexist with symbiotic ants on tree canopies.

In the Arctic tundra, wood ants play an important ecological role in aerating the soil, cycling nutrients, for seed dispersal and, as biological control by preying on forest pest insects during outbreaks. The increase in temperature, caused by climate change, is positively associated with ant abundance.  This could accelerate the wood ants’ effects on the ecosystem, with potentially dramatic consequences for associated taxa. It is, however, still unclear to what extent the ants influence the vegetation and arthropod community. The aim of this study is to investigate the effects ants have on the Arctic tundra ecosystem and how climate change may modify these effects. The study was conducted in Abisko national park, north Sweden, were two study sites were selected: one at low altitude and one at high altitude. I found that wood ants had a substantial effect on the vegetation community close to the mound, with a positive effect on different kind of vascular plant species, and a negative effect on rushes, mosses, and lichens. All the arthropods taxonomic orders and most of the families were positively affected by the presence of ant mounds. Ant mound abundance and volume were positively related with annual insolation and GPP, which indicates that climate change will increase ant abundance in the Arctic tundra. Thus, my results suggest that future climate change will have significant effects on Arctic tundra vegetation and arthropod communities, via positive effects on ant abundance.

In the Arctic tundra, wood ants play an important ecological role in aerating the soil, cycling nutrients, for seed dispersal and, as biological control by preying on forest pest insects during outbreaks. The increase in temperature, caused by climate change, is positively associated with ant abundance.  This could accelerate the wood ants’ effects on the ecosystem, with potentially dramatic consequences for associated taxa. It is, however, still unclear to what extent the ants influence the vegetation and arthropod community. The aim of this study is to investigate the effects ants have on the Arctic tundra ecosystem and how climate change may modify these effects. The study was conducted in Abisko national park, north Sweden, were two study sites were selected: one at low altitude and one at high altitude. I found that wood ants had a substantial effect on the vegetation community close to the mound, with a positive effect on different kind of vascular plant species, and a negative effect on rushes, mosses, and lichens. All the arthropods taxonomic orders and most of the families were positively affected by the presence of ant mounds. Ant mound abundance and volume were positively related with annual insolation and GPP, which indicates that climate change will increase ant abundance in the Arctic tundra. Thus, my results suggest that future climate change will have significant effects on Arctic tundra vegetation and arthropod communities, via positive effects on ant abundance.