Go on through the lofty spaces of high heaven and bear witness, where thou ridest, that there are no gods.
Seneca the Younger

Monitoring of aphids - vector of potato diseases virus - continued in Poland for 30 years in 5 localities, indicated some changes in pressure exerted by these insectes. The biggest differences were observed for Macrosiphum euphorbiae (Thom.) and subsequently for Aphis frangulae Kalt. and Aulacorthum so/ani Kalt. Reduction in population of these aphids has been observed according to elapsing time in all five localities. In case of Myzus persicae (Sulz.) or Aphis nasturtii Kalt., these changes involved decrease or increase of the pressure, depending on the locality.