03120naa a2200253 a 450000100080000000500110000800800410001910000170006024500320007726000090010930000150011849000080013352024490014165000110259065000170260165000120261865000180263065000110264865300110265965300300267065300290270070000210272977301160275014626102010-03-30       2000    bl uuuu     u00u1 u    #d1 aMOSCARDI, F.  aEcology of entomopathogens.  c2000  ap.651. v.2  vv.2  aThe knowledge about the ecology of entomopathogens, especially the factors that affect their epizootics (characterized by a rapid change in the prevalence of a disease on host populations), is the key aspect to be considered for their use in IPM programs. Different groups (bacteria, viruses, protozoa, and nematodes), as well as genera and species within a group, have different characteristics (virulence, speed to kill the host, host range, persistence, susceptibility to abiotic factors, mode of infection, mode of transmission and dispersal, population distribution and density, etc), which, combined to characteristics of the pest population, to the ecosystem considered, and other cultural and control practices adopted will help to define the best approach for use of an entomopathogen in a given IPM program. The approaches of entomopathogen use are: 1) introduction and establishment (classical biological control); 2) environmental manipulation (for conservation and augmentation of the natural occurrence of entomopathogens); 3) inoculative release (application and further multiplication and transmission of the pathogen on host populations); and 4) inundative release (microbial insecticides, applied as needed to maintain host populations below damaging levels, similar to the application of chemical insecticides). Modeling studies have indicated that entomopathogens best suited for introduction and establishment should have moderate virulence, good transmission (horizontal and vertical), and produce high amount of inocula of a persistent and infective stage. On the other side, entomopathogens used as microbial insecticides, should be highly virulent so as to maintain the target insect below damaging levels, and transmission (horizontal and vertical) may relatively unimportant. For proper use of these agents in IPM programs, and considering the current trend towards developing geneticall engineered organisms, in-depth studies about the ecology of entomopathogens will become more and more important. There is an obvious need of research on microecology in the soil substrate and general microenvironment (as the surface of plant substrates), the positive and antagonic interactions with the microflora and microfauna, specially for those entomopathogens which their efficacy highly affected by the environment. Also there is a need to study the relationships of crop phenology with the expression of entomopathogens.  aBrazil  aepidemiology  aInsecta  aEpidemiologia  aInseto  aBrasil  aManejo integrado de praga  aMicrobial control agents1 aSOSA-GOMEZ, D.R.  tIn: INTERNATIONAL CONGRESS OF ENTOMOLOGY, 21., 2000, Foz do Iguassu. Abstracts... Londrina: Embrapa Soja, 2000.