Preliminary communication
https://doi.org/10.31298/sl.145.3-4.4
Preliminary results on narrow-leaved ash (Fraxinus angustifolia Vahl) and green ash (Fraxinus pennsylvanica Marshall) seed entomofauna in Croatia
Jelena Kranjec Orlović
; University of Zagreb, Faculty of Forestry and Wood Technology
Ida Bulovec
; Zagreb
Milivoj Franjević
; University of Zagreb, Faculty of Forestry and Wood Technology
Damjan Franjević
; University of Zagreb Faculty of Science, Department of Biology
Josip Skejo
; University of Zagreb Faculty of Science, Department of Biology
Marin Biliškov
; University of Zagreb Faculty of Science, Department of Biology
Danko Diminić
; University of Zagreb, Faculty of Forestry and Wood Technology
Boris Hrašovec
; University of Zagreb, Faculty of Forestry and Wood Technology
Abstract
Native narrow-leaved ash (Fraxinus angustifolia Vahl) and introduced green ash (F. pennsylvanica Marshall) are two most common ash (Fraxinus spp.)species in Croatian lowland forests, takinga significant place in these ecosystems. In the recent past it has been observed that narrow-leaved ashseed yields have reduced, emphasising the importance of good health status of those collected, as they are used for seedling production and consecutive regeneration of forest stands or afforestation. Given that insects could be an important factor affecting ash seed health status, the aim of this research was to gain insight into the species being present and their frequency in the ash seeds. In total 2.500 narrow-leaved ashand 1.000 green ashseeds from seven different locations were screened for insect presence. Analysed seeds were categorized as undamaged, insect damaged or empty, and observed insect specimens were identified by morphological and molecular genetic analysis. Green ashseeds revealed higher insect infestation in comparison with native ash species, with weevil Lygniodes bischoffii being the most numerous pest found. Narrow-leaved ashseeds were mostly occupied by the native weevil species, L. enucleator. Besides these pests, larval, pupal, and adult stages of parasitoid wasps (Hymenoptera) and larval stage of the seed eating moth Pseudargyrotoza conwagana (Lepidoptera) were found in both ash species. However, given that pests detected in this study prefer urban areas or were present in a very small number of seeds, where they were often followed by parasitoids, it can be concluded that insects currently do not have a significant negative impact on the reproduction of narrow-leaved ashand green ash in forest stands.
Keywords
ash; seed damage; weevils; <i>Lygniodes</i>; parasitoid wasps; <i>Pseudargyrotoza conwagana</i>
Hrčak ID:
257008
URI
Publication date:
30.4.2021.
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