No description available.

The morphology of the internal male genitalia of selected genera of Melanoplinae (Orthoptera: Acrididae) was studied. A detailed comparison of these structures was carried out, in an attempt to identify new characters that may be useful in analyzing relationships between the members of the subfamily. Twenty-two genera were examined, mostly of North American distribution, using one exemplar species for each of them. Standard dissection and drawing techniques were followed. The epiphallus and the apical parts of the aedeagus were found to be the most important taxonomic characters. The genera Aptenopedes and Buckellacris were highly divergent from the rest of the melanoplines, while the close relationship between Appalachia, Dendrotettix and Podisma was confirmed by genital characters. Internal male genitalic characters did not provide significant support for many currently recognized tribes and subtribes, suggesting that there is a great need for reclassification in the subfamily.

Some aspects of the ability of locusts and grasshoppers (Acrididae) to compensate for nutritional shortfalls were studied, with a special emphasis on the factors which constrain this ability. Chapter 1 investigates the effects over the short-term (12 h) of the plant-produced allelochemical tannic acid on the ability of Locusta migratoria (L.) and Schistocerca gregaria (Forskal) to compensate for dilution of dietary proteins and carbohydrates by increasing consumption. Tannic acid had no effect on compensatory feeding by L. migratoria, and stimulated feeding by S. gregaria. Chapter 2 extends this study over the longer-term (fifth instar) for L. migratoria. Over this period, tannic acid restricted intake and reduced growth of those insects fed lowprotein diets, indicating an inhibitory effect on compensatory feeding for protein. In addition, the levels of dietary proteins influenced regulation for carbohydrate intake and, to a lesser extent, vice-versa. A detailed discussion is presented of the ways that some dietary components can influence the intake of others, and how failure to take this into account can lead to poor experimental design and interpretation. Chapter 3 investigates some mechanisms involved in dietary selection by the grasshopper Schistocerca americana (Drury). It was found that S. americana conditioned on distinctly flavoured protein-inadequate diets then tested on nutritionally similar diets with the familiar or a novel flavour, tend to eat more of the novel-flavoured diets. This suggests that conditioned neophilia, possibly in conjunction with aversion learning, may be a factor facilitating dietary selection in acridids. Chapter 4 investigates the patterns of feeding and dietary selection behaviour of the polyphagous grasshopper Taeniopoda eques (Burmeister) in its natural desert habitat. Despite the overwhelming thermoregulatory requirements and unpredictable variability inherent in ecological complexity, these insects nonetheless maintained a pattern of feeding comparable to that observed under controlled laboratory conditions. The patterns of dietary selection behaviour were concordant with some of the mechanisms observed to operate in the laboratory. Chapter 5 addresses an important inadequacy in the methodology currently used to investigate some aspects of nutritional compensation. A computer-generated data set is used to illustrate how the analysis of the currently popular ratio-based nutritional indices may be flawed, and how this may be overcome using as an alternative the analysis of covariance.

No description available.

No description available.

No description available.

Thesis (M. Sc.)--University of Canterbury, 1967. / Includes bibliography.

Thesis (Ph. D.)--Illinois State University, 1999. / Title from title page screen, viewed July 24, 2006. Dissertation Committee: David W. Borst (chair), Angelo P. Capparella, Sabine S. Loew, Edward L. Mockford, Carleton J. Phillips, Douglas W. Whitman. Includes bibliographical references (leaves 77-89) and abstract. Also available in print.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 413-447).

Metarhizium anisoplia var. acridum, a gyphomycetous fungus registered worldwide for grasshopper and locust control, is currently under consideration as a worldwide for grasshopper and locust control, is currently under consideration as a potential alternative to chemical insecticides for grasshopper control in Canada. Research in this thesis has contributed data required for the registration of biological control agents in Canada. A diagnostic PCR assay was developed for the specific detection of M. anisopliae var. acridum DNA. The assay was highly sensitive and effective for the detection of fungal DNA in infected grasshoppers. A survey of southern Alberta soils conducted in the spring of 2004 revealed the presence of Metarhizium spp. at low natural incidennce. Two indigenous isolates demonstrated pathogenicity when bioassayed against laboratory-reared and field collected grasshoppers. One of the isolates demonstrated virulence comparable to a commercial isolate. An analysis of historical weather data revealed that summer weather in the Prairie provinces should not preclude the efficacy of M. anisopliae var. acridum under local conditions. / xv, 127 leaves : ill. (some col.) ; 28 cm.