[Effect of the length of the stay of the male on the reproduction of the olive psylla Euphyllura olivina Costa (Homoptera, Psyllidae)].

We have studied, in Euphyllura olivina Costa, 1839, the incidence that the absence or presence of males can have on the fecundity of females their longevity, the duration of spawning and other biotic parameters... So we have pointed out that: In all the cases, from beginning of experimental infestations of olive--tree sprouts to the beginning of eggs releasing, there is a preovipositional time of very variable duration. Virgins, isolated from imago emergence, have a trifling spawning and the eggs cannot have parthenogenetic development. Fecundity of a female by one male induces important spawnings. These increase with more and more prolonged cohabitation (2, 4, 8 and 16 days stay). When one female is in the presence of two males we have noted a very hight variability of fecundity of the female. However it appears that the most important spawnings occur when the two males and the female are left together during 8 days.