Dissertação
Modelos para a interação da lagarta Anticarsia gemmatalis com o fungo entomopatogênico Metarhizium rileyi
Fecha
2016-08-22Autor
Machado, Silvia Barcelos
Institución
Resumen
In this work we propose a discrete-time model, composed by a system of di erence equations
to represent the dynamics of interaction of the velvetbean (Anticarsia gemmatalis)
and the entomopathogenic fungus Metarhizium rileyi. Anticarsia gemmatalis is a pest
that attacks soybean crop, reducing the leaf area, and consequently causing damage
to the production. The fungus M. rileyi is a naturally occurring entomopathogen and
provided the weather conditions are appropriate, it acts as a biological control agent
of the soybean caterpillar, it can drastically reduce the population density in crops.
Through a simple model for the interaction, we note that, depending on the parameters
taken, the fungal is able to reduce the susceptible caterpillars density. We veri ed that
the susceptible caterpillars density is reduced drastically when inundative applications
fungus are made. Finally, supposing that the fungus reproduces faster than the soybean
caterpillar scale, we veri ed that the biological control exercised by the fungus causes
susceptible caterpillars density to decrease considerably.