- Tytuł:
-
Rozmieszczenie zimujących stadiów przedimaginalnych osnui gwiaździstej Acantholyda posticalis Mats. w drzewostanach sosnowych będących ogniskami gradacyjnymi szkodnika
Distribution of wintering pre-imaginal stages of the great web-spinning pine sawfly Acantholyda posticalis Mats. in Scots pine stands being the outbreak centres - Autorzy:
-
Sławski, M.
Mokrzycki, T.
Perliński, S.
Rutkiewicz, A.
Sławska, M. - Powiązania:
- https://bibliotekanauki.pl/articles/980205.pdf
- Data publikacji:
- 2019
- Wydawca:
- Polskie Towarzystwo Leśne
- Tematy:
-
lesnictwo
drzewostany sosnowe
szkodniki roslin
osnuja gwiazdzista
Acantholyda posticalis
larwy zimujace
eonimfy
pronimfy
rozmieszczenie przestrzenne
autumn survey
scots pine pests
eonymphae
pronymphae
abundance
distribution variability - Opis:
- Acantholyda posticalis Mats. for over twenty years increases the extent of occurrence and causes defoliation of Scots pine stands. The population size is estimated annually based on the autumn surveys of phytophagous insects, but accuracy of these prognoses is far from satisfactory. The aim of the study was to describe the spatial distribution of pre−imaginal stages of A. posticalis wintering in the litter and soil to improve the methods of survey currently applied in Polish forestry. The research was carried out in four forest district located in different regions of Poland. In each forest stand three following zones were outlined: the belt of trees on the edge of the stand adjoining to young plantation or thicket, the belt 15−20 m from the stand edge and the belt in the forest interior at least 30−40 m from the edge of a stand. 152 trees were examined and 1540 plots of size 1×0.5 m were established under their canopy. The pre−imaginal stages were searched within each of these plots in the litter and soil to the depth of 20 cm. Later on they were divided into eonymphae and pronymphae, and counted. The significant differences in number of pre−imaginal stages of A. posticalis between studied forest stands in different forest districts were found. The spatial distribution of larvae wintering in the litter and soil was highly variable in scale of both stand and single tree. The abundance of larvae depended on the distance from the forest edge, but the values of this parameter calculated for trees in the same zone also varied substantially. The lowest mean abundance of pre−imaginal stages of A. posticalis denoted under pines growing at the edges of trees stand. Within the canopy projection on forest floor, the distribution of larvae was significantly dependent on the distance from the tree trunk. The highest abundance was observed within one meter from the trunk. The survey method currently used for primary pine pest assessment in Polish forests bases on ten plots and five of them are located 1.5 m from the tree trunk. In the light of presented results, the assessment of A. posticalis number could be inaccurate, because half of these plots in which scrutiny of litter and soil take place, omit the areas of higher concentration of wintering stages of the pest.
- Źródło:
-
Sylwan; 2019, 163, 07; 556-563
0039-7660 - Pojawia się w:
- Sylwan
- Dostawca treści:
- Biblioteka Nauki
Artykuł