Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"egg mortality"”.
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The effect of turbulence on survival, dispersal, and swimming behavior of grass carp eggs and larvae
… their spread consists of increasing capture and mortality rates during early life stages (i.e. eggs and larvae stages) when they are more susceptible to damage via enhanced flow turbulence levels and altered flow conditions. In order for these alternative strategies to be effective, is necessary …
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Egg cannibalism by anchovy in the Southern Benguela Current Region
… the stomach contents were determined and anchovy eggs in the stomach were counted. Anchovy eggs in CalVET net samples were counted and staged. Frequency distributions of densities of eggs in the plankton on the Agulhas Bank and off the West Coast were plotted to compare egg density in the two …
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Biochemical and cell biological studies of cytoplasmic incompatibility in Drosophila
… by Laven (1959), results in high levels of egg mortality. CI arises when females of one strain are mated to males of another strain (usually from geographically separated regions): such crosses yield few or no progeny. CI has been linked to the presence of a Rickettsia-like endosymbiont …
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Aspects of the ecology of Scolypopa australis (Walker) (Homoptera:Ricaniidae) and its parasite Centrodora scolypopae (Valentine) (Hymenoptera: Aphelinidae)
… vine hopper, Scolypopa australis Walker, and its egg parasite, Centrodora scolypopae Valentine, were studied in a bracken and blackberry filled gully near Hamilton, New Zealand, from 1980-85. The S. austral is egg population was estimated using a height frequency vegetation sampling method and the …
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Cascading Effects Of Predator Removal On The Ecology Of Sea Turtle Nesting Beaches
… crab predation are among the highest causes of egg mortality for sea turtles in Florida and raccoons are intraguild predators of ghost crabs. Because of the damage done to sea turtle nests, raccoons have been removed from some beaches during the sea turtle nesting season. I compared the diet and …
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Egg and larval ecology of anchovy (Engraulis capensis) and sardine (Sardinops sagax) in the Southern Benguela ecosystem
… and distribution of anchovy and sardine eggs and larvae in the southern Benguela ecosystem were investigated during 14 cruises over 2 consecutive summer upwelling seasons as part of the South African Sardine and Anchovy Recruitment programme (SA-SARP). Cruises were conducted each month …
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Efficacy of Botanical and Mineral Oils on Willamette Mite (Acari: Tetranychidae)
… in Shandon, CA) tested effects on adult mite and egg populations, with five treatments: Omni Oil®, Ecotrol®, Nexter®, Ecotrol® + Nexter®, and water as a control. Laboratory experiments tested effects on adult females and eggs. Treatments were Omni Oil®, Ecotrol® (1.0%), Ecotrol® (0.5%) and water …
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Assessing effects of an overwinter dewatering on the egg-to-fry survival of brown trout in a Montana stream
… trout and bull trout; they occur at the critical egg-to-fry development phase, possibly reducing oxygen flow to the eggs and increasing the rate of sub-gravel freezing. This study was designed to examine the effects of a wintertime industrial water diversion on redd building and egg-to-fry …
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Assessing effects of an overwinter dewatering on the egg-to-fry survival of brown trout in a Montana stream
… trout and bull trout; they occur at the critical egg-to-fry development phase, possibly reducing oxygen flow to the eggs and increasing the rate of sub-gravel freezing. This study was designed to examine the effects of a wintertime industrial water diversion on redd building and egg-to-fry …
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Smallmouth bass mortality during parental care: implications for year-class strength
I tested hypotheses that daily mortality rates (DMR) of smallmouth bass offspring were influenced by life stage, density and growth, parental male attributes, fungus infection (egg stage), and predation during parental care in the North Anna River, Virginia. In 1994, stream discharge was relatively …
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Compatible components of the integrated pest management of Bathycoelia distincta (Hemiptera: Pentatomidae
… focusing on entomopathogenic fungi and egg parasitoids Trissolcus basalis (Wollaston, 1858) (Hymenoptera: Platygastridae). Landscape context and elevation were the principal factors that explained species richness and arthropod size. Species richness and insect size decreased with …
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Contributions toward the integrated pest management of diamondback moth, Plutella xylostella (L.), on collards in Virginia
… 99%) of P. xylostella died from natural causes. Mortality factors varied between the two regions. Neonates, small larvae, and large larvae disappearing were major mortality factors. Rainfall, predation, and dispersal probably contributed the most to this mortality. Egg mortality played a bigger …
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Sexual maturation in sea- and freshwater phases of Pacific salmonids and investigations of reproductive hormone involvement in osmoregulatory adaptation
… females, but there was no correlation between egg mortality and blood sodium at ovulation. Later in the season, as salinity in net pens decreased, chinook fertility increased. At the beginning of the chum migration season, when salinity was lowest, chinook fertility was equal to that of chum …
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A comparison of the insecticidal properties of New Zealand native and other plants
… diet of the LBAM and their extracts on larval mortality, pupation, adult emergence, egg fertility and egg mortality were evaluated. D. spectabile leaf extracts caused significant larval mortality and some of the adults which emerged from those larvae were malformed. Fecundity and fertility of …
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Understanding Bed Bug (Cimex lectularius (L.)) Egg Susceptibility to Different Insecticide Treatments
Bed bug (Cimex lectularius L.) eggs are the most difficult life stage to eradicate and are often the reason that pest management professionals must apply multiple treatments over time in an infested home. This dissertation was aimed at developing a better understanding of how we might improve bed …
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Bionomics of Epiphyas postvittana, Ctenopseustis obliquana, Planotortrix excessana (Lepidoptera: Tortricidae) and Stathmopoda "skelloni" (Lepidoptera: Stathmopodidae) on apple cv 'Dougherty' in Auckland
… other characters, and keys to the leafroller eggs and pupae are provided. A technique to successfully mate C. obliquana and P. excessana in the laboratory was formulated by predicting the emergence time of female pupae and enclosing one such pupa with several males. A colony of C. obliquana …
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THE ANTAGONISTIC AND MUTUALISTIC PLANT-INSECT INTERACTIONS OF PITCHER’S THISTLE (CIRSIUM PITCHERI [TORR. EX EAT.] TORR. & A. GRAY, ASTERACEAE), A FEDERALLY THREATENED GREAT LAKES DUNE AND COBBLE SHORE ENDEMIC PLANT
… The seed head weevil is univoltine and lays eggs in thistle heads. The developing larva chews the ovules or seeds before emerging as an adult to overwinter in leaf litter. I repeatedly surveyed Pitcher's thistle plants from three populations in northern lower Michigan for impacts. The insect …
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Identifying mechanisms of pyrethroid resistance in the navel orangeworm and novel methods of control
… the resistant population produces more CHCs in eggs and adults. I carried out a series of bioassays of topical toxicity to determine if elevated CHCs in the resistant population contribute to differences in egg and larval mortality through bifenthrin sprays. R347 egg mortality was reduced at low …