Density-dependent and density-independent effects on outbreak dynamics in an invasive forest insect

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60460709%3A41320%2F25%3A106285" target="_blank" >RIV/60460709:41320/25:106285 - isvavai.cz</a>

Výsledek na webu

<a href="https://link.springer.com/content/pdf/10.1007/s10340-025-02006-w.pdf?utm_source=clarivate&getft_integrator=clarivate" target="_blank" >https://link.springer.com/content/pdf/10.1007/s10340-025-02006-w.pdf?utm_source=clarivate&getft_integrator=clarivate</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s10340-025-02006-w" target="_blank" >10.1007/s10340-025-02006-w</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Density-dependent and density-independent effects on outbreak dynamics in an invasive forest insect

Popis výsledku v původním jazyce

Several bark and wood-boring insects exhibit eruptive population dynamics during which declining host vigor triggers rapid insect population growth and widespread tree mortality. The invasive woodwasp Sirex noctilio F. (Hymenoptera: Siricidae) is typically considered a semi-aggressive species due to the absence of aggregation pheromones and a strong dependence on density-independent factors. However, in many parts of its invaded range, S. noctilio displays pronounced outbreaks and spatial aggregation, suggesting more complex population mechanisms. We hypothesized that S. noctilio behaves as an aggressive forest insect in its invaded range, where population dynamics are driven by a combination of both density-independent (host condition) and density-dependent (population density) mechanisms. To test this, we conducted a field experiment in an invaded region, where host susceptibility was manipulated using herbicide-induced stress, and local population density was assessed by selecting plantations with contrasting wasp densities. We jointly investigated the effects of these factors on female host selection and offspring performance. We found that host stress strongly influenced female host selection, whereas local population density had little influence on the probability of attack. In contrast, larval performance was largely unaffected by host stress but exhibited positive density-dependent effects, with more and larger individuals emerging from trees in plantations with higher S. noctilio population densities. These positive density-dependent responses are inherently destabilizing and likely contribute to the pattern of eruptive population dynamics seen in invasive populations of this forest insect.

Název v anglickém jazyce

Density-dependent and density-independent effects on outbreak dynamics in an invasive forest insect

Popis výsledku anglicky

Several bark and wood-boring insects exhibit eruptive population dynamics during which declining host vigor triggers rapid insect population growth and widespread tree mortality. The invasive woodwasp Sirex noctilio F. (Hymenoptera: Siricidae) is typically considered a semi-aggressive species due to the absence of aggregation pheromones and a strong dependence on density-independent factors. However, in many parts of its invaded range, S. noctilio displays pronounced outbreaks and spatial aggregation, suggesting more complex population mechanisms. We hypothesized that S. noctilio behaves as an aggressive forest insect in its invaded range, where population dynamics are driven by a combination of both density-independent (host condition) and density-dependent (population density) mechanisms. To test this, we conducted a field experiment in an invaded region, where host susceptibility was manipulated using herbicide-induced stress, and local population density was assessed by selecting plantations with contrasting wasp densities. We jointly investigated the effects of these factors on female host selection and offspring performance. We found that host stress strongly influenced female host selection, whereas local population density had little influence on the probability of attack. In contrast, larval performance was largely unaffected by host stress but exhibited positive density-dependent effects, with more and larger individuals emerging from trees in plantations with higher S. noctilio population densities. These positive density-dependent responses are inherently destabilizing and likely contribute to the pattern of eruptive population dynamics seen in invasive populations of this forest insect.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10616 - Entomology

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Pest Science

ISSN

1612-4758

e-ISSN

1612-4758

Svazek periodika

99

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

12

Strana od-do

1-12

Kód UT WoS článku

001629556200001

EID výsledku v databázi Scopus

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