Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2001. / Härtill 4 uppsatser.

Thesis (Ph.D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 26, 2007) Vita. Includes bibliographical references.

A thorough taxonomic revision of the tribe Phisidini is completed. Fourteen genera and 96 species (of which 8 genera and 59 species are new) are described, redescribed or diagnosed and illustrated. Five previously described species are synonymized, one homonym is renamed. African species formerly assigned to Phisis are now excluded. The morphology of the tribe, particularly the terminology of the male genitalia, is clarified. A phylogeny of the tribe, upon which the classification is proposed, is suggested. Keys at both supraspecific and species levels are given. Details of known geographical distribution ranges and patterns for each species are indicated; the significant geographical variations are discussed for some species. The possible origin and spread of the tribe is discussed on the basis of inferred phylogeny and present distribution; that is, this tribe probably has a Gondwanaland origin, both vicariance and trans-ocean dispersal being likely to have affected its speciation.

No description available.

No description available.

Tettigoniidae (katydids) has more than 7200 species and is the largest family within the insect order Orthoptera. Their unique biology including leaf-like crypsis, acoustic signaling, and courtship rituals garners much of their academic attention. However, the taxonomy of katydids is chaotic and previous to these studies, little work had been done to decipher the phylogenetic relationships within this family. Without a robust phylogenetic framework, questions regarding the evolution of katydid disguises including the leaf-like crypsis cannot be addressed. This dissertation contains three chapters. Chapter 1 provides the first phylogenetic hypothesis focusing on Tettigoniidae. In this chapter we show a character thought to be taxonomically informative, the thoracic auditory spiracle, is homoplasious within Tettigoniidae. We provide evidence that the leaf-like wings of katydids have been derived independently in multiple lineages. Additionally, in Chapter 1 the problematic taxonomy within Tettigoniidae, particularly the lack of monophyly in many of the larger and widespread subfamilies, is addressed. Chapter 2 contains a more in depth look into the evolution of crypsis. Leaf-like wings are common throughout Tettigoniidae, but the definition of leaf-like has varied by author. In this second chapter we provide a ratio method for differentiating between leaf-like and non leaf-like wings. Our ratio method was then verified using geometric morphometics. We found at least 15 independent derivations of leaf-like wings in Tettigoniidae. Furthermore we found that throughout Tettigoniidae the leaf-like wings are not a driver of speciation and selection may favor a shift away from the leaf-like wings. Within the cosmopolitan Phaneropterinae, the trend differs, as there is no significant difference between the speciation and transition rates of the leaf-like and non leaf-like lineages. Chapter 3 presents the largest and most comprehensive phylogeny for Tettigoniidae to date and provides a hypothesis for origins and biogeographic dispersal of katydids. Characters that define subfamilies are similar due to similar selective pressures and are not taxonomically informative. As a result, many of the larger and widespread subfamilies, particularly those with species in similar but geographically distant habitats, are paraphyletic. In this chapter we also provide temporary names to define the two large clades containing the bulk of Tettigoniidae diversity (tettigonioid clade and phaneropteroid clade) in addition to smaller subfamily groups to simplify discussion of katydid relationships until a higher-level taxonomic revision is completed.

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on October 18, 2007) Vita. Includes bibliographical references.

Bei vielen Laubheuschreckenarten produzieren nur die Männchen Gesänge, hauptsächlich um arteigene Weibchen anzulocken und sich mit Rivalen zu messen. Die Produktion der durch sexuelle Selektion ausgewählten akustischen Signale kostet das singende Männchen Energie. Die Gesangsleistung kann aufgrund der unterschiedlichen Körperqualität von Männchen zu Männchen variieren, was zu relevanten Konsequenzen für das Ergebnis der sexuellen Selektion führt. In dieser Arbeit soll die Auswirkung sexueller Selektion auf sekundäre Merkmale der Männchen untersucht werden, wie die Größe der Organe zur Schallproduktion und die Struktur akustischer Signale. Der Fokus liegt dabei auf den Faktoren, die die Qualität des Signalgebers und die Zusammensetzung des sozialen Umfelds bestimmen. Um diese Ziele zu erreichen, werden zwei Laubheuschreckenarten Poecilimon ampliatus und Poecilimon v. veluchianus untersucht. Die morphologischen Befunde zeigen, dass die positive Selektion auf klangproduzierende Strukturen mit der Präferenz von Weibchen für schwerere Männchen übereinstimmt und daher Rückschlüsse von der Körpermasse der Männchen auf die Größe der schallerzeugenden Organe gezogen werden können. Die Ergebnisse der akustischen Daten betonen die entscheidende Relevanz der Kombination verschiedener Umweltfaktoren. Sie zeigen, wie Männchen auf akustische Signale reagieren, die von benachbarten Konkurrenten erzeugt werden, indem sie ihre Signalerzeugung kohärent an die Stärke der Konkurrenz und ihren persönlichen energetischen Status anpassen. Männchen beider Arten zeigen eine interindividuelle Variation in der Fähigkeit, ihre Signalproduktion anzupassen, die sowohl durch Faktoren wie die Körpermasse des Männchens und der Populationsdichte beeinflusst wird. In zukünftigen Untersuchungen könnte der Frage nachgegangen werden, wie Männchen in der Natur von ihrer Kondition abhängige Signale und alternative Verhaltensstrategien entwickeln. / Behaviours and structures related to mating are under sexual selection. Due to their costs, these traits honestly reflect the quality of the signaller. Using structures located on the wings, bushcricket males signal to attract females and repel rivals. Sound performance can vary between individuals of different body conditions, leading to relevant consequences for the outcome of sexual selection. This thesis aims to investigate the effect of sexual selection on secondary male traits, such as the size of sound production organs and the structure of acoustic signals. The focus is on the factors that determine the quality of the signaller and the composition of the social environment. To fulfil the aims, two bushcrickets species were used: Poecilimon ampliatus and Poecilimon v. veluchianus. In P. ampliatus, sexual selection plays a role in determining the size of morphological structures that are responsible for producing female-preferred acoustic signals. A positive relationship between body condition and size of sound-producing organs was found. Heavier and larger males had larger wing and longer stridulatory file with disproportionally longer and less dense stridulatory teeth. A further effect of sexual selection is highlighted during the acoustic contest. In both species, only heavy males shown plasticity in acoustic behaviour. Moreover, the sound produced in competition honestly reflects the males’ body condition. In P. ampliatus heavier males signal at higher effort than lighter males and increased their activity when the light rival was placed at a closer distance. In P. v. veluchianus heavy males increased their signal activity only when the number of light rivals increased. Future endeavour will be to study how males in nature evolve condition-dependent signalling and alternative behavioural strategies.

No description available.

No description available.