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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
331

A transputer-based image analysis sytem for the analysis of leaf consumption by insect herbivores and leafminers

Kwok, Kam-cheung 01 January 1991 (has links)
No description available.
332

Benthic Macroinvertebrates of Temperate, Sub-Antarctic Streams: The Effects of Altitudinal Zoning and Temperature on the Phenology of Aquatic Insects Associated to the Robalo River, Navarino Island (55°S), Chile

Contador Mejías, Tamara Andrea 12 1900 (has links)
The Cape Horn Biosphere Reserve, within the remote Sub-Antarctic ecoregion is a reservoir of expressions of biological and cultural diversity. Although it is considered one of 24 wilderness areas remaining in the world, it is not free from local and global threats, such as invasive species, and climate change. Field biologists and philosophers associated to the Sub-Antarctic Biocultural Conservation Program and the Omora Ethnobotanical Park, have worked to describe the region’s biocultural diversity, linking ecological and philosophical research into education, ecotourism, and conservation, through a methodology called field environmental philosophy (FEP), which integrates ecological sciences and environmental ethics through a 4-step cycle consisting of: 1) interdisciplinary research; 2) composition of metaphors; 3) design of field activities with an ecological and ethical orientation; and 4) implementation of in situ conservation areas. In this context, the purposes of this dissertation were to: 1) provide a comprehensive review of publications regarding the conservation status of aquatic and terrestrial insects at a global scale and with an emphasis in southern South America; 2) study the distribution of benthic macroinvertebrates through the sharp altitudinal gradient of the Róbalo River watershed; 3) describe the life histories of Gigantodax sp (Simuliidae: Diptera) and Meridialaris chiloeense (Leptophlebiidae: Ephemeroptera) in the Róbalo River and to assess the potential effects of climate change on their phenology; and 4) to apply FEP methodology in order to better understand and communicate the intrinsic and instrumental values of freshwater invertebrates in the Cape Horn Biosphere Reserve.
333

A morphological study of the external female genitalia and spermatheca of some Calendra

Curtis, De Mar H. 01 May 1959 (has links)
The genus Calendra is the largest genus of the sub-family Rhynchophorine. There have been 116 species described from the United States and Mexico. At the present time only 71 are recognized as valid species. About 50 of the 71 species occur in the United States and Canada.
334

The external male genitalia of some rhynchophora

Bruhn, Arthur F. 01 May 1946 (has links)
Today there is an increasing recognition among taxonomists of the importance of consideration of the complete morphology of insects in classifying them and in arrangming them in their logical phylogenetic sequence. Regarding the Rhynohophora, with which this paper is concerned, some progress toward a more complete understanding has been made. In 1912 Sharp and Muir made a study of the male genital tube of the coleoptera in general and observed that the various specializations they noted in the forms of Rhynohophora examined would doubtless be of future significance. Tanner in 1927 made a similar important study of the female genitalia and subsequently has included both the male and the female genitalia in desciprtions of new species, as noted in his study of the subtribe Hydronomi. Stickney in 1923 examined and repoted his findings on the head capsule. Boving and Craighead in 1931 published the results of their studies of the larval forms. Ting in 1936 compiled the results of a rather comprehensive study of the mouth parts of the Rhynohophora alone.
335

The distribution of overwintering arthropods in a sheep pasture in Utah County, Utah

Ashley, Richard Frank 01 May 1968 (has links)
The parasitic mites on mammals living in the chaparral community of Utah are practically unknown ecologically. Keegan (1953) was the first to publish on parasitic mites from Utah. He listed mites of 12 species and 9 genera from Tooele and Juab counties from hosts which included one Peromyscus truei, five P. crinitus, and 20 P. maniculatus. Brennan and Beck (1955) published on the chiggers of Utah and included a key to 38 species. Allred (1954, 1956, 1957, 1958) studied the geographical distribution, seasonal occurrence, and biology of mites found on mice of the genus Peromyscus in Utah.
336

Factors Affecting Metabolism During Non-Feeding Stages in Insects

Cambron, Liz Doralyn January 2020 (has links)
Although feeding is important for optimal development and growth in insects, there are several points during the insect life cycle that are non-feeding: metamorphosis, pupation, and overwintering. Non-feeding periods also occur in response to internal cues, such as feedback from nutrient thresholds and immune responses being activated. Additionally, as an insect goes through different developmental stages, its nutritional requirements change in response to or in preparation for non-feeding periods. Most physiological responses like feeding are regulated through an interconnection of pathways, but how these networks change in response to different energy demands, such as immune challenges or changes in metabolism, is poorly understood. One significant pathway that is involved in regulating several physiological processes is the insulin signaling pathway. In my dissertation research, I tested hypotheses explaining the regulation of physiological processes during non-feeding periods in two agriculturally relevant insects, Manduca sexta and Megachile rotundata. First, I investigated how internal cues such as dietary lipid content and immune challenges cause non-feeding periods in M. sexta. Then, I investigated how insulin signaling regulates development during a non-feeding period like overwintering changes in M. rotundata. Since the insulin signaling (IIS) pathway is critical for development and growth, I focused on testing if this pathway plays a role in regulating non-feeding periods. My research showed that increased dietary lipid content causes a cessation of feeding, which suggests there is a possible lipid threshold that when reached, causes M. sexta to switch from lipid consumption for storage to lipid excretion. When looking at another cue like immune challenges, my results showed that during a bacterial infection, a Toll-mediated suppression of IIS pathway may be regulating feeding and causing a non-feeding period exhibited as sickness-induced anorexia. Lastly, my results also showed that the IIS pathway is suppressed in overwintering M. rotundata, and that this process can change in response to temperature. Overall, my dissertation research showed that the insulin signaling pathway and nutrient content play a vital role in regulating non-feeding periods. Investigating insulin signaling, lipid metabolism, and innate immunity in these species closes a gap in knowledge of invertebrate development.
337

Flight path of pollinators foraging on impatiens : decision rules and their implications for gene flow

Dubé, Denis January 1989 (has links)
No description available.
338

The effect of environmental variability on heritabilities and genetic correlations of traits in the field cricket, Gryllus pennsylvanicus /

Simons, Andrew M. (Andrew Michael) January 1993 (has links)
No description available.
339

Some insect and vertebrates recovered from the coprolites of prehistoric Indians of Southwestern Tamaulipas, Mexico.

Marsh, David C. January 1965 (has links)
No description available.
340

Systematic approach for analysing and presenting information about insect groups with special reference to Thysancoptera, metamorphosis, and phylogenies.

Damant, Robert Lawrence. January 1981 (has links)
No description available.

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