Life history traits of Sirex noctilio F. (Hymenoptera: Siricidae) can explain outbreaks independently of environmental factors.
2013
The woodwasp Sirex noctilio is a major pest
of pine plantations worldwide. Economically significant damage is
however limited to outbreak populations. To understand what
determines outbreaks dynamics in this species, we developed an
individual based model for a wasp population developing within a
pine plantation. We show that outbreaks may be the result of the
insect's life history. Specifically we show that limited dispersal
may not only increase population persistence but also create the
conditions for eruptive dynamics. When the probability of long
distance dispersal is greater than zero, but relatively small
($P_{LDD}$= 0.1) large outbreaks are the norm, with all of the
suitable trees dead at the end of the simulation. For $P_{LDD}$= 0
(only local dispersal allowed) outbreaks are smaller in size, and
in some cases not well defined and spread over longer periods. For
$P_{LDD}$= 1 (only long distance dispersal allowed), the frequency
of local population extinction (without outbreaks) increases
significantly. Aggregated attacks may induce physiological changes
in the trees which could allow other wasps to detect them. These
changes may in turn trigger an outbreak. In contrast, healthy,
vigorous trees are not suitable for wasp oviposition. In our model
the density of suitable trees (healthy trees but yet suitable for
oviposition) are a key factor determining population persistence
before outbreaks. From an applied perspective, our results
emphasize the importance of adequate plantation management in
preventing woodwasp infestation.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
48
References
9
Citations
NaN
KQI