Door gif of het weer? Vraagtekens rond het verdwijnen van de Koninginnepage

Discussion on the reduction of Papilio machaon population in The Netherlands by three authors. The number of P. machaon observed in The Netherlands has decreased sharply since the early 19S0’s. Apart from factors like climate and urbanisation, the use of insecticides in agriculture could largely be held responsible for this phcnomenen. Since 1900 there has been a fluctuation in the number of P. machaon. Statistics have shown that this coincides with the temperature rate during the given period. The northwest boundary of the distribution area of P. machaon is located in The Netherlands. Small changes in climate, like the cooler summers of the 50’s and 60’s may couse a shift of this area to the south. Reduction of mobile butterfly species such as P. machaon due to insecticides is unlikely.