Sirex noctilio

• Avispa de los pinos

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Dinamica de pulsos eruptivos

• Pulse Eruptive outbreaks

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Outbreaks can last several generations,

spread from favorable epicenters to large

areas of forest through dispersal,

require positive density dependence.

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Outbreak is terminated through resource depletion or natural enemies

Outbreak is triggered

Sirex noctilio has pulse eruptive dynamics (Berryman, 1988)

Que explica los estallidos?

Hipotesis

Madden (1998):

Density independent factors (e.g., sequia)

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Corley (2007):

Density dependent factors (e.g., agregacion)

Long term study

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• 29 sitios x 16 years (1998-2013)

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• 1015 trees censados anualmente

Como eran los estallidos

• Mas agregacion especial a mayores niveles de ataque

Lantschner & Corley (2015) PlosOne

Corley et al. (2007) Ent. Exp et Appl.

Aparicio et al. (2013) Math. Bio. Eng

Mas frecuencia en sitios cercanos a estallidos

Poblaciones cercanas

Patrones observados

NE Slope aspect implies drier conditions in Patagonia

Topografia

Lantschner & Corley (2015) PlosOne

• Mas insectos

• Mas arboles apropiados

Probabilidad de estallidos vs. distancia a otro estallido

Sincronizacion a escala regional

Índice basado en el balance de agua en el suelo. Su magnitud indica que tan lejos estamos de condiciones normales

Entonces…

Epidemic

Endemic

Population level

Exctintion zone

Severe drought

A lorry full of woodwasp- bearing logs

or dispersal

Unstable outbreaks threshold

Implications for management

Natural enemies: nematode & parasitoids

Human-aided spread controls

Forest management sensu lato

• Outbreaks vary in magnitude.
• Outbreaks in the presence of natural enemies.
• Outbreaks in “good” years/sites/species.

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Our model can explain: