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

Result code in 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>

Result on the web

<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>

Result language

angličtina

Original language name

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

Original language description

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.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10616 - Entomology

Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2025

Confidentiality

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

Name of the periodical

Journal of Pest Science

ISSN

1612-4758

e-ISSN

1612-4758

Volume of the periodical

99

Issue of the periodical within the volume

1

Country of publishing house

DE - GERMANY

Number of pages

12

Pages from-to

1-12

UT code for WoS article

001629556200001

EID of the result in the Scopus database

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