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Dispersal by flight is obligatory for bark beetles in the subfamily Scolytinae. Adult bark beetles must leave the natal host and fly to seek new hosts for brood production. Because of the eruptive nature of some bark beetle populations, dispersal capacity has implications for beetle spread and invasion across the landscape. Bark beetle dispersal can occur over short distances within a stand or over long distances above the forest canopy, where wind aids dispersal. Despite the obvious importance of dispersal for predicting population spread, knowledge gaps in understanding factors that influence bark beetle dispersal remain. In this review, we synthesize information on bark beetle flight to gain a better understanding of this important life history trait. We assess the impact of genetic, physiological, and morphological traits on flight in different bark beetle species. We also consider the impact of abiotic and biotic environmental conditions on flight. We discuss how measurements of these factors could contribute to the development of comprehensive models to better predict spread of bark beetle populations. Through the synthesis of flight research on a variety of bark beetle species, this review provides suggestions for future avenues of research on this important aspect of bark beetle ecology. Key words: Scolytinae, flight, dispersal, bark beetle. Le vol est le moyen de dispersion obligatoire chez les scolytes dans la sous-famille des Scolytinae. Les scolytes adultes doivent quitter l'hote ou ils sont nes et s'envoler pour chercher de nouveaux hotes afin d'assurer leur progeniture. A cause de la nature eruptive de certaines populations de scolytes, la capacite de dispersion a des repercussions sur la propagation et l'invasion de l'insecte dans le paysage. La dispersion des scolytes peut survenir sur de courtes distances a l'interieur d'un peuplement d'arbres ou sur de longues distances au-dessus du couvert forestier ou le vent favorise la dispersion. Malgre l'importance evidente de la dispersion pour predire la propagation de la population, il y a encore des lacunes dans les connaissances concernant la comprehension des facteurs qui influencent la dispersion des scolytes. Dans cette revue de litterature, nous resumons l'information sur le vol des scolytes pour avoir une meilleure comprehension de cet aspect important du cycle vital. Nous evaluons l'impact des traits genetiques, physiologiques et morphologiques sur le vol chez les differentes especes de scolytes. Nous discutons de la fa^on dont la mesure de ces facteurs abiotiques et biotiques pourrait contribuer au developpement de modeles complets pour mieux predire la propagation des populations de scolytes. Par le biais de la synthese de la recherche sur le vol chez une variete d'especes de scolytes, cette revue de litterature fournit des suggestions pour de futures avenues de recherche sur cet aspect important de l'ecologie des scolytes. [Traduit par la Redaction] Mots-cles: Scolytinae, vol, dispersion, scolytes., 1. Introduction Bark beetles, sensu stricto, breed and spend most of their life underneath the bark of the host tree. Adult beetles eventually leave the natal host to search for [...]

This paper proposes a system of integro-difference equations to model the spread of Carcinus maenas, commonly called the European green crab, that causes severe damage to coastal ecosystems. A model with juvenile and adult classes is first studied. Here, standard theory of monotone operators for integro-difference equations can be applied and yields explicit formulas for the asymptotic spreading speeds of the juvenile and adult crabs. A second model including an infected class is considered by introducing a castrating parasite Sacculina carcini as a biological control agent. The dynamics are complicated and simulations reveal the occurrence of periodic solutions and stacked fronts. In this case, only conjectures can be made for the asymptotic spreading speeds because of the lack of mathematical theory for non-monotone operators. This paper also emphasizes the need for mathematical studies of non-monotone operators in heterogeneous environments and the existence of stacked front solutions in biological invasion models. [ABSTRACT FROM AUTHOR]