01693naa a2200229 a 450000100080000000500110000800800410001902400570006010000220011724501310013926000090027052009860027965000140126565000120127965000140129165000120130565300260131765300150134370000190135870000300137777300560140710472122023-04-03       2005    bl uuuu     u00u1 u    #d7 ahttps://doi.org/10.1590/S0006-870520050002000102DOI1 aSILVA, A. de A. E  aEffect of the inherent variation in the mineral concentration of alfafa cultivars on aphid populations.h[electronic resource]  c2005  aPlants have inherent variability of mineral content which affects their physiology and consequently the herbivorous insects feeding on them. Besides, insects need considerable amounts of potassium, phosphorus and magnesium in their diets, whereas little calcium, sodium and chloride are required. In this study, the inherent variation on mineral (Ca, S, Mg, N, P, K and also C:N ratio) concentrations and aphid (Acyrthosiphon spp., Therioaphis maculata, Aphis craccivora) populations on three alfalfa (Medicago sativa) cultivars (P3; Crioula, the most widely cultivated in Brazil, and CUF 101, an aphid-resistant) were studied between September/1997 and August/1998. A significant variation on mineral concentrations and aphid populations was observed among different sampling times and cultivars. The correlations between C:N ratio, Mg, N, P and S concentrations and aphid density variation suggest that the mineral status affects aphid population dynamics under field conditions.  aAphididae  aInsecta  aNutrients  aMineral  aPlant insect relation  aResistance1 aVARANDA, E. M.1 aPRIMAVESI, A. C. P. de A.  tBragantia, Campinasgv. 64, n. 2, p. 233-239, 2005.