Study of actual and estimated irreplaceable mortality caused by parasitoids on Spodoptera frugiperda eggs

• Grant number: 13/04455-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2013
• End date: December 31, 2013
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Odair Aparecido Fernandes
• Grantee: Dayane Andrade dos Reis
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

Understanding which factors lead to mortality of organisms and why population densities fluctuate in time has been the subject of several studies during the 20th. century. Naturally or anthropic occurring factors, comprehension of spatial distribution, magnitude, and moment of occurrence are essential for population dynamics studies. Multidecremental life table allows describing and quantifying mortality in a population. However, interferences and overlaps of contemporaneous mortality factors can occur. Therefore, mortality studies should take into consideration irreplaceable mortality. Despite this, even being widely utilized, an experiment under controlled conditions to compare the actual value and the irreplaceable mortality caused by two or more factors have never been carried out. Thus, bioassays will be performed to evaluate the mortality proportion caused by parasitoids (Telenomus Remus e Trichogramma pretiosum) acting solely or contemporaneously on Spodoptera frugiperda eggs. The value of irreplaceable mortality will be calculated by subtracting the number of eggs parasitized by one species in the presence and in the absence of the other. This value will be also compared to predicted irreplaceable mortality, estimated using M-DEC program. With the results, we aim to confirm if the irreplaceable mortality values estimated by M-DEC program are similar to the actual irreplaceable mortality values. (AU)