02495nam a2200157 a 450000100080000000500110000800800410001910000190006024501280007926002190020752018250042665000230225165000240227470000160229870000230231419146392012-02-08       2011    bl uuuu     u00u1 u    #d1 aTEODORO, A. V.  aRelative contribution of environmental factors to the population dynamics of the dassava Green Mite.h[electronic resource]  aIn: TROPENTAG 2011: CONFERENCE ON INTERNATIONAL RESEARCH ON FOOD SECURITY, NATURAL RESOURCE MANAGEMENT AND RURAL DEVELOPMENT, Bonn, 2011. Development on the margin: book of abstracts. Bonn: University of Bonnc2011  aThe producing landscape of Northeast Brazil is dominated by smallholder agriculture. Slash and burn management practices are still used by local farmers to cultivate staple crops such as cassava (Manihot esculenta), which is attacked by a variety of pests, including the cassava green mite Mononychellus tanajoa (Acari: Tetranychidae). This pest is responsible for high yield losses in Brazil and may be kept in check by naturally occurring predatory mites of family Phytoseiidae. In addition to predatory mites, environmental factors may also contribute to regulate pest populations in the field. We evaluated the population dynamics of M. tanajoa and the most abundant predatory mite found in the study region, the generalist phytoseiid Euseius ho (Acari: Phytoseiidae), over the cultivation cycle (11 months) of cassava in four farms. In each farm, 10 cassava plants were randomly selected and 6 leaves taken monthly, totaling 60 leaves per farm per month. The number of mites per leaf was recorded and subsequently converted into number of mites per cm2. Moreover, we determined the relative contribution of biotic (abundance of E. ho) and abiotic (rainfall, temperature and relative humidity) environmental factors to the abundance of M. tanajoa. The abundance of M. tanajoa was high and increased whereas the abundance of E. ho was low and remained constant throughout the cultivation cycle of cassava. Hierarchical partitioning analyses revealed that most of the variance for the abundance of M. tanajoa was explained by rainfall and relative humidity followed by E. ho abundance and temperature. In conclusion, although the generalist predatory mite E. ho contributed to regulate populations of the cassava green mite the main mechanisms explaining the abundance of M. tanajoa were abiotic environmental factors.  abiological control  aControle Biológico1 aREGO, A. S.1 aSILVA, A. C. B. da