author(s)
Noubissi Youmbi Elisabeth, Yana Wenceslas and Tamesse Joseph Lebel

abstract
Milicia excelsa (Welw) C.C. Berg is among the most valuable important timber species in Cameroon. National programs of establishing plantation of M. excelsa have been constrained by the gall forming psyllid, Phytolyma fusca. This paper focused on the population dynamics of P. fusca, was conducted in an experimental M. excelsa plantation in Yaounde. Psyllid galls were counted in situ, collected and dissected under laboratory conditions. Adults and larval stages were counted. The results showed, in 2009, three periods of psyllids outbreaks: February - April, August - October and November - December. Seven generations of the pest are noted. In 2010, three periods of psyllids outbreaks are noted: January - February, May - September and November - December. Six generations of the pest existed. The number of generations varies from one year to another and depends on the phenology of the host plant which depends on the climatic factors.