01647naa a2200277 a 450000100080000000500110000800800410001910000210006024501190008126000090020052008870020965000110109665000120110765000130111965000110113265000130114365000170115665300110117365300110118465300130119565300160120865300220122465300170124665300160126377300900127918069432001-06-12       2001    bl uuuu     u00u1 u    #d1 aBARROS, A. T. M.  aDynamics of Haematobia irritans irritans (DipterabMuscidae) infestation on nelore cattle in the Pantanal, Brazil.  c2001  aFrom june 1993 to may 1995, horn fly counts were conducted twice a month on untreated nelore cattle raised extensively in the Pantanal. Horn fly population showed a bimodal fluctuation and peaks were observed every year after the beginning (november/december) and at the end (may/june) of the rainy season, which coincided with mid-late spring and mid-late fall, respectively. Horn flies were present on cattle throughout the year in at least 64% of the animals. Mean horn fly numbers on animals did not exceed 85 flies/cow during peaks and were under 35 flies/cow in most of the remaining periods. The highest infestations (population peaks) were short and dropped suddenly within two weeks. Less than 15% of the animals in both herds could be considered as "fly-susceptible" - showing consistently higher infestations, or "fly-resistant" - showing consistently lower infestations.  aBrazil  aecology  aPantanal  aBovino  aEcologia  aInfestação  aBovine  aBrasil  aHorn fly  aInfestation  aMosca-dos-chifres  aSazonalidade  aSeasonality  tMemorias do Instituto Oswaldo Cruz, Rio de Janeirogv.96, n.4, p.445-450, may., 2001.