Infestación de insectos

In February 2012, a Desert Locust outbreak suddenly developed in southwest Libya along the border of Algeria and rapidly spread into adjacent areas of southeast Algeria. Gregarizing adults laid eggs throughout March in both countries. Monitoring and control operations are hampered by the remoteness of the area as well as heightened insecurity due to 2011 events in Libya.

A second generation of hatching commenced in late March and early April in southwest Libya and southeast Algeria where a Desert Locust outbreak is in progress. This is expected to cause locust numbers to increase significantly on both sides of the common border and lead to a potentially dangerous situation in which swarms form and invade the northern Sahel of West Africa at the beginning of summer.

Currently, the hatchlings are forming many dense hopper groups and bands in both countries at densities of more than 5,000 hoppers/sq. metre. Some of the hoppers have reached the second instar stage in...

Reed beds of Phragmites australis in the River Amudarya delta near the Aral Sea constitute permanent breeding areas of the Asian Migratory locust, Locusta migratoria migratoria. Every year, thousands of hectares are treated with broad-spectrum insecticides to prevent locust swarms from damaging crops in adjacent areas. To devise efficient locust monitoring and management plans, accurate and updated information about the spatial distribution of reeds is necessary. Given the vast geographic extent of the delta, traditional, ground survey methods are inadequate. Remotely sensed data collected by the MODIS sensor aboard the TERRA satellite provide a useful tool to characterize the spatial distribution of reeds. Multi-temporal MODIS data, collected at different times of the growing season, were used to generate spectral-temporal signatures for reeds and other land cover classes. These spectral-temporal signatures were matched with reed phenology. MODIS information was...

The current outbreak of mountain pine beetle (Dendroctonus ponderosae) in western Canada has been
increasing over the past decade and is currently estimated to be impacting 9.2 million hectares, with varying
levels of severity. Large area insect monitoring is typically undertaken using manual aerial overview sketch
mapping, whereby an interpreter depicts areas of homogenous insect attack conditions onto 1:250,000 or
1:100,000 scale maps. These surveys provide valuable strategic data for management at the provincial scale.
The coarse spatial and attribute resolution of these data however, make them inappropriate for fine-scale
monitoring and operational planning. For instance, it is not possible to estimate the initial timing of attack
and year of stand death. In this study, we utilise eight Landsat scenes collected over a 14 year period in northcentral
British Columbia, Canada, where the infestation has gradually developed both...

The Twentieth century saw fundamental shifts in northern Eurasian political and land-management paradigms, in Russia culminating in the political transition of 1991. We used the 1972 to 2001 Landsat archive bracketing this transition to observe change trends in southern central Siberian Russia in primarily forested study sites. Landsat resolved conifer, mixed, deciduous and young forest; cuts, burns, and insect disturbance; and wetland, agriculture, bare, urban, and water land covers. Over 70 percent of forest area in the three study sites was likely disturbed prior to 1974. Conifer forest decreased over the 1974 to 2001 study period, with the greatest decrease1974 to 1990. Logging activity (primarily in conifers) declined more during the 1991 to 2001 post-Soviet period. The area of young forest increased more during the 1974 to 1990 time period. Deciduous forest increased over both time periods. Agriculture declined over both time periods contributing to forest...

Disturbance of the vegetated land surface, due to factors such as fire, insect infestation, windthrow and
harvesting, is a fundamental driver of the composition forested landscapes with information on disturbance
providing critical insights into species composition, vegetation condition and structure. Long-term climate
variability is expected to lead to increases in both the magnitude and distribution of disturbances. As a
consequence it is important to develop monitoring systems to better understand these changes in the
terrestrial biosphere as well to inform managers about disturbance agents more typically captured through
specific monitoring programs (such as focused on insect, fire, or agricultural conditions). Changes in the
condition, composition and distribution pattern of vegetation can lead to changes in the spectral and thermal
signature of the land surface. Using a 6-year time series of MODerate-resolution Imaging...

The River Ili delta in southeast Kazakhstan is an important permanent breeding area for the Asian migratory locust (Locusta migratoria
migratoria). Preventing locust swarms from flying out of the delta and damaging crops in adjacent areas is the primary objective of locust
management programs in the region. In this study the utility of Landsat Enhanced Thematic Mapper Plus (ETM+) data was tested for mapping
land cover and identification of reed areas within River Ili delta. Through digital processing of the satellite data, a land cover map was
generated (overall accuracy = 79%, Kappa value = 0.745) and potential locust habitats of importance to pest managers were identified. ETM+
data were effective in identifying areas with reed monoculture, the primary locust habitat (Conditional Kappa value = 0.905), and areas with
reeds and water (Conditional Kappa value = 0.865). However, ETM+ data were less effective in identifying sites where reeds...

Disturbance of the vegetated land surface, due to factors such as fire, insect infestation, windthrow andharvesting, is a fundamental driver of the composition forested landscapes with information on disturbanceproviding critical insights into species composition, vegetation condition and structure. Long-term climatevariability is expected to lead to increases in both the magnitude and distribution of disturbances. As aconsequence it is important to develop monitoring systems to better understand these changes in theterrestrial biosphere as well to inform managers about disturbance agents more typically captured throughspecific monitoring programs (such as focused on insect, fire, or agricultural conditions). Changes in thecondition, composition and distribution pattern of vegetation can lead to changes in the spectral and thermalsignature of the land surface. Using a 6-year time series of MODerate-resolution Imaging Spectroradiometer(MODIS) Land Surface Temperature (...

Millions of invading caterpillars have forced thousands of Bong County residents to flee their homes and the situation is getting worse. The caterpillars, also known as army worms, have destroyed crops, entered houses and contaminated water sources with their faeces.

Source : Glide number

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