Kovács I. Endre szerk.: Rovartani Közlemények (Folia Entomologica Hungarica 12/1-23. Budapest, 1959)

The abundanciea listed la the table« /I emphasize again their appro x ima tiveneaa/ calculated by the following proportion for every day of survey. The essence of this proportion - as found also by Van der Dri ft - lies in the number of recaught from the known number of marked beetlee. Van der_Drift marked his recaptured beetles on one occasion only, on the other hand, I marked then always at the time of their recapture when doing the respective surveys. I constructed the proportion on the basis of the following reflection: e preponderantly higher amount of beetles were marked on a previous occasion than recaptured on the next one. If these two numbers /marked and recaught/ were related to the number of caught specimens of the day's survey /marked and unmarked/ and the unknown population, then, after having made the necessary calculation, I received the value of abundancy for the whole 1200 m

2

, that is, assuming an ideally equal distribution of food on the floor of a Potentillo-Quercetum during the spring. The number of the marked specimens is M

a", the number of the recaught ones is „b

H

, the total number of the caught ones is „B", and the number of the unknown population is „x"; and so the proportion: a:b m B:x and x: _ b.B X • S E.g.: On the 25

th May 8 /B/ Necrophorus humator Goeze were caught in square I.,and 3 /b/ were recaptured specimens of 10 /a/ beetles marked on the 21

st May. Two specimens transmigrated,of therefore I added them to the number of the recaught ones /b/. So: a = 10 10:5 « 8:x b » 3+2=5 ELS. a B = 8 1 ' To 34 x - ? x = 4