Effect of High Temperature on the Growth and Reproduction of Corn Aphids (Homoptera: Aphididae) and Implications for Their Population Dynamics on the Northeastern Iberian Peninsula

The development, reproduction and longevity of corn aphids Rhopalosiphum padi (L.), Sitobion avenae (Fabricius) and Metopolophium dirhodum (Walker) were studied at 18, 22, 25, 27.5 and 30ЊC.Only nymphs of R. padi survived at 30ЊC, but the adult reproductive capacity was very low.Rhopalosiphum padi performed better than M. dirhodum at all temperatures tested, and better than S.avenae over the range of 22Ð27.5ЊC.The better performance of R. padi was due to a lower nymphal mortality, lower developmental and prereproductive times and a higher intrinsic rate of increase (r m ).Sitobion avenae had a higher r m than M. dirhodum at all temperatures.The most suitable temperature for population development was Ϸ28.5ЊC for R. padi, 26.5ЊC for S. avenae and 24.5ЊC for M. dirhodum, suggesting the ability of aphid populations to adapt to high temperatures in the Iberian peninsula.The role of temperature as a key factor in determining aphid population dynamics in the northeastern Iberian peninsula is discussed.