Cork oak pests: a review of insect damage and management

Abstract

Abstract& Key message Cork oak decline is widespread in all its distribution range and seems to be triggered mainly by both mismanagement and unfavorable climatic factors. As a result, cork oak forests become susceptible to pest attack, which accelerates the onset of decline. Pest management strategies for this valuable and highly biodiverse ecosystem are examined in this review, taking into account the main insect pests and how their impact on cork oak forests is affected by climate change. While monitoring pests may provide the tools to predict the transition from endemic to epidemic insect populations, forestry practices (sanitary felling), biological control, and trapping are some of the most promising measures in protecting cork oak forests. & Context Over the last decades, cork oak (Quercus suber L.) decline has affected millions of trees throughout its distribution range. Cork oak is a typically Mediterranean species remarkably relevant for the biodiversity and landscape conservation of vast evergreen oak forests. Cork oak is also well known and highly valued for cork production. Climatic changes, management practices, and biotic factors, particularly plant pathogens and insect pests, play a decisive role in tree death and market devaluation of cork. & Aims Here, we review the major insect pests possibly involved in cork oak decline, while discussing pest management strategies. & Methods A survey of the current literature was performed to identify major insect pests affecting cork oak trees, as well as to establish the most promising pest management strategies under climate change. & Results Many authors seem to agree that the decline is triggered by both anthropogenic and abiotic factors, such as the mismanagement of cork oak forests and unfavorable climate (high temperatures and droughts). Consequently, trees become susceptible to pests and pathogens, which accelerate the onset of decline. & Conclusion Since a further increase in temperatures and droughts is expected, developing adequate management strategies to adapt cork oak trees to climate change, while simultaneously preventing and reducing insect pest attacks, is of foremost importance in the effort to conserve these unique and highly diverse ecosystems.Keywords Quercus suber . Cork oak decline . Climate change . Forest management Handling Editor: Aurelien SALLE Contribution of the co-authors Riziero Tiberi and Tiziana Panzavolta: conceived the idea, supervised literature reviewing, wrote the manuscript, and reviewed its final version. Manuela Branco: contributed to the writing of the manuscript, the reviewing of literature, and the revision of the final draft. Matteo Bracalini: contributed to the writing of the paper, the selection of literature, and the English revision of the manuscript. Francesco Croci: contributed to the writing of the manuscript and the assembling of related literature. All authors have read and approved the final manuscript.

Dispersal and Propagule Pressure of Botryosphaeriaceae Species in a Declining Oak Stand is Affected by Insect Vectors

“…Here, the repeated occurrence of heat extremes, accompanied by a decrease in precipitation and thus prolonged summer drought, has caused substantial heat and water stress to tree vegetation, resulting in their physiological impairment, stunted growth, dieback and, in some instances, mortality [6]. Climate-driven changes, besides having exacerbated the vulnerability of the trees, have also modified the dynamics of forest insects and pathogens, dramatically increasing the likelihood of attacks by these damaging agents [7,8].…”

Long-Term Assessment of Selective Pruning of Quercus Species for Controlling Populations of Coraebus florentinus (Coleoptera: Buprestidae) in Mediterranean Forests

“…Regardless of the damage caused by C. florentinus, strategies for controlling its populations are scarce or non-existent (see the introduction section), and silvicultural management by pruning damaged branches is the main option employed [8,26]. In fact, the same authors proposed monitoring the biology of the insect in the southern Iberian Peninsula, studying also the economic costs of mechanical control by pruning in a "dehesa" with 87% infestation.…”

Influence of Bacillus thuringiensis application timing on population dynamics of gypsy moth in Mediterranean cork oak forests

“…Cork production ranges from 150 to 5000 kg of cork per hectare every 10 years, depending on the main land use . The time interval between two consecutive cork extractions is generally 10–12 years, possibly with longer intervals when adverse climate or pest infestation events occur in the year of debarking …”

“…Gypsy moth, Lymantria dispar (L.) (Lepidoptera: Erebidae) is one of the main forest defoliators worldwide and is able to defoliate thousands of hectares in the same year during its outbreaks. [1][2][3][4][5][6] Although the gypsy moth feeds on > 300 host species, 7 it is strongly associated with Quercus spp., such as cork oak (Q. suber L.), downy oak (Q. pubescens Willd.) and holm oak (Q. ilex L.) in the Mediterranean region, 3,5,8 and white oak (Q. alba L.) and northern red oak (Q. rubra L.) in North America.…”

“…[1][2][3][4][5][6] Although the gypsy moth feeds on > 300 host species, 7 it is strongly associated with Quercus spp., such as cork oak (Q. suber L.), downy oak (Q. pubescens Willd.) and holm oak (Q. ilex L.) in the Mediterranean region, 3,5,8 and white oak (Q. alba L.) and northern red oak (Q. rubra L.) in North America. 9 Mediterranean cork oak forests represent one of the most interesting biodiversity hotspots worldwide 10,11 and, at the same time, are an important cultural and economic resource for rural communities.…”