<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>3</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">De Sousa, E M R</style></author><author><style face="normal" font="default" size="100%">Inacio, M L</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Lieutier, F and Ghaioule, D</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">New aspects of Platypus cylindrus Fab. (Coleoptera : Platypodidae) life history on cork oak stands in Portugal</style></title><secondary-title><style face="normal" font="default" size="100%">Entomological Research in Mediterranean Forest Ecosystems</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><publisher><style face="normal" font="default" size="100%">INST NATL RECHERCHE AGRONOMIQUE</style></publisher><pub-location><style face="normal" font="default" size="100%">147 RUE DE L'UNIVERSITE, 75007 PARIS, FRANCE</style></pub-location><pages><style face="normal" font="default" size="100%">147-168</style></pages><isbn><style face="normal" font="default" size="100%">2-7380-1194-2</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Platypus cylindrus is an Ambrosia beetle known to attack mainly dead and&lt;br/&gt;weakened trees. However, the new outbreak in cork oak stands in Portugal&lt;br/&gt;since the 1980's, has led to new hypotheses about the insect - host&lt;br/&gt;relationships. Although its biology has been studied since the beginning&lt;br/&gt;of the 20(th) century, it is not sufficiently known to enable a&lt;br/&gt;quantitative analysis of P. cylindrus population dynamics. Recent&lt;br/&gt;studies carried out in Portugal have developed new approaches to the&lt;br/&gt;understanding of host selection and colonisation mechanisms, insect&lt;br/&gt;bio-ecology and insect-fungus symbiosis. Host selection by P. cylindrus&lt;br/&gt;mainly depends on factors associated not only with the stand and tree&lt;br/&gt;characteristics (weakness, dimensions) but also with exploitation&lt;br/&gt;methods (decorking intensity and period). On the other hand, the&lt;br/&gt;colonization process appears to be very structured on the tree surface&lt;br/&gt;with a quasi-systematic vertical gradient of density and high rates of&lt;br/&gt;attack on the same tree suggesting the presence of aggregation&lt;br/&gt;pheromones. The insect life cycle takes place inside the tree over a&lt;br/&gt;long period of time and the temporal variability of egg laying results&lt;br/&gt;in the coexistence in the galleries of P. cylindrus descendants at&lt;br/&gt;different stages. of development. Space management strategies can e&lt;br/&gt;responsible for this behaviour. Because of this out of phase life cycle,&lt;br/&gt;the emergence period is long (from spring to autumn), and may extend to&lt;br/&gt;a second generation during the spring of the following year. The new&lt;br/&gt;observed symbiotic associations involving P. cylindrus can be partially&lt;br/&gt;understood as an evolution, suggesting that more favourable conditions&lt;br/&gt;have been developed. Recent results confirm that P. cylindrus is&lt;br/&gt;associated with a complex of six Ambrosia fungi. The presence of&lt;br/&gt;pathogenic fungi in the insect galleries suggests that this symbiosis&lt;br/&gt;can contribute to the weakness of the host providing the ideal&lt;br/&gt;conditions for the insect establishment.</style></abstract></record></records></xml>