02098naa a2200313 a 450000100080000000500110000800800410001910000180006024501710007826000090024952011460025865000100140465000350141465000130144965000150146265000190147765300200149665300160151665300290153265300230156165300240158465300310160865300130163965300130165265300130166565300130167870000230169177300700171417872321996-02-12       1975    bl ---       0--  u    #d1 aLEVINE, N. D.  aMicrometeorological factors involved in development and survival of free-living stages of the sheep nematodes Haemonchus contortus and Trichostrongylus colubriformis.  c1975  aTemperature and soil moisture are the most important factors affecting the development and survival of haemonchus contortus and Trichostrongylys columbriformis eggs and larvae on pasture. More than half of the eggs develop into infective larvae in the laborato- ry, but a very low percentage (0.03% for H. contortus) does so on pasture. there is a marked difference between H. contiortus and T. colubriformis in survival on infective larvae. H. contortus larvae survided in the winter at Urbana poorly, whereas T. colubrifor- mis did well. The former durvived better in the spring and worse in the sdummer, while both survived equally well in the fall. Technics for larval recovery from pasture are not very efficient. Meteorologic conditions at ground level where the larvae exist are quite different from those in a standard weather shelter 1.6 m above the ground. Bioclimatographs in which mean monthly maximum temperatures are plotted against total monthly precipitation are fairly good in predicting the type of nematode liable to be important in a given region, but they are too simplistic to be relied on for more than approximations.  asheep  aTrichostrongylus colubriformis  aCarneiro  aNematóide  aSobrevivência  aDesenvolvimento  aDevelopment  aFator micrometeorologico  aFree-living stages  aHamonchus contortus  aMicrometeorological factor  aNematode  aParasita  aParasite  aSurvival1 aTODD JUNIOR, K. S.  tInternational Journal Biometeorologygv.19, n.3, p.174-183, 1975.