A Bug's Life

In our century increasing societal, environmental and economic pressures force us to develop new agricultural pest management strategies (Lima and Berryman, 2006). The main goals of the research is to find ways to decrease environmental degradation from the use of chemicals, reduce the amount of weeds and how to increase crop yield. Simulation models are being done by the University of Budapest and they are examining the relationships between pests, plants and the environment. They are engaging in several studies that investigate the impact on insect populations caused by global warming. Some of these studies are done in laboratories and others require field observations and discoveries.
There are a few methods of gathering research and information. The use of Palaeontology is one of them. By looking into a regions past we can see how that region has changed in respect to vegetation and insects. For example, the transition from parkland vegetation and insects to the one of coniferous forest of south-western Ontario region indicates that the climate continued gradually warm through the mid-Holocene (Schwert et al., 1985). The increasing temperature allows insects to thrive in places before could not of survived.
Another way of gathering research is by using simulation models. It is a handy tool that is used to find out the reaction of a system to an event or multiple events. One of the models is called the Northern Corn ROOTWORM Model and is described as a process - orientated simulation model that examines the population dynamics of corn - rootworm in the northern United States. The rootworm attacks both the roots and tassels of corn, decreasing yields. The model examines how planting date affects the population dynamics of the insects. It gives information on phenology and the number of individuals in each growth state of corn. The model can analyze global change impact on the population levels and distribution of the insects, as well as the potential economic impacts (Norango and Sawyer, 1989). There are other models such as the boundary layer model and boll weevil model that help scientists to gather information and come to conclusions.
Weather and climate are major factors that determine the development and spreading of insects. Current estimates of changes in climate indicate an increase in global mean annual temperature of 1 degree Celsius by 2025 and 3 degree Celsius by the end of the next century (Memmott et al., 2007). The forecasted increase in temperature will surely increase the population of bug sizes and there ability to live in areas that were once before inhabitable. Also forecasted increases in CO2 in the air are most likely to have an affect on insect and plant interactions. Insect populations tended to increase slightly when there was elevated CO2. The combination of increasing temperatures and elevated CO2 levels may increase insect damage to certain plants. Humidity and solar radiation will also have a large effect on insect populations in the future. All of the above changes in climate will likely increase insect transport from region to region.
Elevated CO2 even though it may increase insect population size, it will have a more positive effect on crops. These effects include yield stimulation, improved resource use efficiency, more successful competition with weeds, reduced O3 toxicity, and in some cases better pest and disease resistance. However, some of these beneficial effects may be lost, at least to some extent, in a warmer climate. Warming accelerates plant development and reduces grain-fill, reduces nutrient-use efficiency, increases crop water consumption and favours weeds over crops. Also, the rate of development of insects may be increased (Fuhrer, 2003). The warming favours insects more then the plants. There will be less days in the winter that are really cold and this will allow the insects to have a higher survival rate.
Examining the results of the experiments it is hard to draw any conclusions. Even though plant populations will most likely increase due to the warming we do not know how plants will react to it. Also with increased technology comes newer ways to kill insects. More research will need to be done before any conclusions can be drawn on this topic, but one thing is for sure is that we will have to brace for a future that is unknown and hope we can control the insects.
Article can be found at.... http://www.ecology.kee.hu/indvol08_2.htm

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References





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