Simulation of population of the mosquito Aedes vexans (Diptera: Culicidae) in intermittent wetlands.

摘要

This thesis presents a simulation model of Aedes vexans (Meigen) populations from egg to adult. The model uses information about an individual wetland, its initial egg numbers and water level, and subsequent weather to predict the number and schedule of adults emerging. Predictions are compared with observed numbers of eggs and larvae over several years in Minnesota habitats. Sensitivity to various factors is also examined.; Chapter 1 describes a model of larval development and survival, using rate summation and distributed development techniques to simulate age increase and distribution. Results showed the importance of water temperature for both duration of larval development and for survival. Observed field survival (30% to 50% overall) was at or below predicted values, but sampling precision limited further interpretation.; Chapter 2 adds description of oviposition and egg hatch to the larval model, to predict population dynamics in relation to habitat water level over time. Results showed good correlations between predicted and observed populations, although the exact population numbers did not always match. The most influential factor affecting total adult production in these sites was the size and frequency of water level changes. Long-term changes in water levels also appeared to affect habitat attractiveness for oviposition.; Chapter 3 describes a simple wetland hydrology model, combining a runoff model with evaporation and seepage loss to predict daily water level. Predicted water level changes were close to actual changes in most of the 5 study sites in most of the 6-8 years monitored, although discrepancies caused by accumulated error in water loss estimates occurred in several site-years. Water level increase was strongly affected by rainfall amount, and measured rainfall sometimes differed widely between close locations. This model provided some inputs for Chapter 2, and could be used for future studies.; These models of mosquitoes and hydrology in individual wetlands provide a base of understanding that can be used to guide future landscape-scale analysis of this species.