Forster, B.; Knizek, M.; Grodzki, W. (eds.) 1999: Methodology of Forest Insect and Disease Survey in Central Europe.
Proceedings of the Second Workshop of the IUFRO WP 7.03.10, April20-23, 1999, Sion-Chiiteauneuf, Switzerland.
Birmensdorf, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) 36-41.
THE DOMINANT PEST AND INJURIOUS AGENTS IN SLOV AKIA M. ZUBRIK, J. NOVOTNY, M. TURCANI, R. LEONTOVYC
Forest Research Institute Zvolen, Research Station Banskti Stiavnica, Lesnicka 11, 969 23 B.
Stiavnica
The effect of forest stands health conditions on incidental fellings and its trends
General decrease of the vitality and stability of forest stands, caused by weather anomalies, emissions, wind, snow, insects, fungi infections etc. results in the decline of commercially and ecologically important forest tree species. Worsened health conditions of Slovakia's forests reflected also in the volume of salvage and incidental fellings. The proportion of incidental fellings in total volume of harvested timber in Slovakia was more than 50 % in 1993. This trend has lasted up to now. In 1994 it reached almost 60 % and currently remains at this level.
A high proportion of incidental fellings results in stopping or delaying planned regeneration or tending treatments what might be of destabilising effect on the forest ecosystems being already disturbed.
In 1998 incidental felling reached 2.20 mil m3 of timber which represented 41.7 % of total annual cut (5.27 mil m3). For coniferous species the proportion of incidental fellings reached 58.7 %, for broadleafs 18.6% (fig. 1).
Fig. 1 Proportion of incidental fellings in total volume offellings (in%)
70 60 50 40 20 10 0
1985 86 87 88 Abiotic injurious factors
89 1990 91_ 92
Year 93 94 95 96 97 98
The greatest damage on forest stands cause a group of mechanically acting factors - wind, snow, rime (Fig.2). Compared to 1996 and 1997 the volume of incidental fellings, being caused by wind, snow and rime, decreased in 1998. Increase of wind incidental felling in 1996-1997 was mainly due to the whirlwind of 8 July 1996 which affected most forest stands with prevalence of spruce in OLZ (forest enterprises) Ciemy Balog, Slovenska :Cupca, Krivan and Benus. The group of mechanically acting injurious factors affected in 1998 about 1,1 mil m3 of timber (in 1997 2.3 mil m\ Almost 94% (about 1.0 mil m3) of that number was the damage by wind.
Fig.2: Damage caused by abiotic injurious factors
3000
2500
,.,2000
...
e= =
C>
!-<1000 -=
500
0
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 Year
Of the other abiotic injurious factors the most important was drought (130711 m3). Fires damaged about 6400 m3 of timber. Abiotic injurious factors (wind, snow, rime, drought, fires and unknown reasons) damaged altogether about 1.39 mil m3 of About 1.25 mil m3 of timber (90.1 %) was processed. Abiotic factors damaged spruce the most. Windbreaks for spruce reached more than 0.75 mil m3 and for beech (0.21 mil m3).
Phytopathogenic micro-organisms
In 1998 10 000 m3 of timber were attacked by wood-destroying fungi in the forests of Slovakia which was an decrease of 50 % compared to the year 1997. In last year about 8000 m3 of timber were processed. Rot damaged mostly spruce and beech trees .
During the period 1988-1998 1.7 mil m3 timber was attacked by phythopathogenic micro- organisms. From that volume about 70% (1.2 mil m3 ) were attacked by tracheomycoses, which attacked 48 500 m3 of oak timber in 1998. Comfared to 1997 a slight decrease was found. The volume ofunprocessed timber was 40 000 m in 1998. The most affected regions according to the volume of attacked timber are as follows: Levice, Topofcany, Kosice, and Krupina. Moreover the tracheomycoses were found also on spruce trees, elms and beech trees (see Fig. 3)
Fig.3: Damage caused by phytopathogenic micro-organisms
250
200
..,
El150
1
:s!-<
50
0
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 -Year
The occurrence of needle casts in the cultures are fluctuating each year depending on the climatic conditions. In 1998 they were found on the area of 8 ha which is lower count of 85 % compared to 1995 (see Tab. 1).
Tab. 1. The main kinds of phytopathogenic micro-organisms
Injurious Attacked Processed To be processed
factor mj ha mj ha mj ha
Rots 9628 0 7927 0 1701 0
Tracheomycoses 48594 157 40009 117 8585 40
Needle casts 0 3 0 3 0 0
Cancers 372 5 201 5 171 0
Honey fungus 11586 1 10190 1 1396 0
Other 12613 11 12301 10 312 1
Together 82793 177 70628 136 12165 41
Based on the records for 1998 11500 m3 of timber had to be processed in Slovakia due to a honey fungus attack. In past few years the attack of fungus Armillaria ostoyae on spruce stands was more frequent and thus this fungus is becoming a significant injurious factor in the spruce stands on acid sites.
Insect pests
Bark beetles and wood borers
The eight-toothed spruce bark beetle (Ips typographus) and smaller eight-toothed spruce bark beetle (Ips amitinus) are the most significant pests. The infestation of spruce forests was in Slovakia for 1998 537 613m3· The Spis and Tatra regions were infested the most, namely in the counties of Poprad, Spisska Nova Yes and Gelnica
Fig. 4: Damage caused by bark beetles
1200
1000
'S 8 0 0
1
600400
lOO
1987 1988 1989 1990 1991 1994 t99S 1996 1997 1998
For Ips typographus and Ips amitinus control totally 36071 trap trees were prepared (159 % compared to 1997). The number of pheromone traps was higher, reaching 31 629 ( 12700 more than in 1997). Preventive or sanitation chemical treatment was applied on 91 083 m3 of timber.
Pine bark beetle (Pityogenes chalcographus) infested almost 26 200 m3 of timber and about 96% of that volume was processed. The most infested were the counties Spisska Nova
Ves, Banska Bystrica and Detva. For pine bark beetle control 1481 trap trees and 2714 pheromone traps were used and 1370 m3 of timber was treated chemically.
Oak (bark) beetle (Scolytus intricatus) is the most significant one of bark beetles on broad- leaved trees, especially as the vector of oaks tracheomycosis. Infestation by this pest was 7200 m3 (Tab. 2).
Tab. 2. Main kinds of bark beetles and wood borers
To be Traps Pheromone traps Chemical
Species Infested Processed pro- light average heavy light heavy treatment cessed
mJ pes ml
lps 537618 477678 59940 13732 12983 9356 20369 11260 91083 typographus
Pityogenes 26171 25049 1122 670 527 284 1923 791 1378
chalcographus
Xyloterus 6533 6478 55 415 268 147 0 0 104
lineatus
Pine bark 5872 4669 1203 13 0 0 0 0 100
beetles
Scolytus 7268 7057 211 23 161 166 0 0 10
intricatus
Other 4787 4037 750 0 0 0 0 0 0
Together 588249 524968 63281 14853 13939 9953 22292 12051 92675
Leaf-eating and sucking insects
The year 1998 was characteristic for high infestation by leaf roller (Tortricidae) and loopers (geometric worms) (Geometridae) on oaks. Several year lasting suitable conditions for the development of these species and optimal course of spring weather resulted in the of outbreak of both pests (occurring in the stands parallel) on the area of 5 000 - 7 000 ha of forests. Compared to 1997 it was low decrease of the pests abundance. The greatest areas infested were recorded in the forest enterprises LOZ Kosice, LOZ Sobrance, OLZ Levice and LOZ Presov. The course of the outbreaks was very quick and the outbreaks resulted in 50- 70
% defoliation, only rarely in clear-eating. Aerial treatments were performed on 1000 ha.
In 1998 there were not more serious problems with the gypsy moth (Lymantria dispar). Its abundance reached basic population count, in some regions its number increased markedly (Cifare) compared to 1997. Weak insect feeding was recorded in some localities with the area of about 400 ha.
Fig. 5: Damage caused by leaf-eating insects
15000
10000
5000
1987 1988 1989 1990 1991 1995 1996 1997 1998
The area of stands damaged by false spruce webworm (Cephaleia abietis) has not changed markedly compared to previous year (184 ha). The pest usually occurs in northern areas of Slovakia (Cadca).
Pine sawflies (Diprion pini, Neodiprion sertifer) were recorded on 74 ha whereas they caused only slight damage to the stand. The highest occurrence was recorded, similarly to previous year, in western Slovakia.
Silver fir woolly aphid (Dreyfusia normannianae) was recorded on 147 ha in surroundings ofBanska Bystrica.
Other aphids were identified as the reason of damage on relatively great area of the stands (228 ha). Beech was the most damaged tree species. Based on field observations this category is comprising aphids on broad-leaved species (their infestation is very heavy in some localities) and in smaller extent also beech scale (Cryptococus fagi). In spite of its high occurrence on large area direct damage on the stands was not observed.
Feeding of cockchafer imagos (Melolontha sp.) occurred in Slovakia only locally in oak stands with the area of 109 ha. Grubs damage was recorded only in pine plantations on the area 113 ha (Tab. 3).
Tab. 3. Main kinds of leaf-eating and sucking insects in 1998 Damage
Injurious factor slight heavy together
ha
Geometrid moths on oaks 3040 241 3281
Leaf-roller moths on oaks 3825 1350 5175
Gypsy moth 438 10 448
False spruce webworm 184 0 184
Silver. fir woolly aphid 97 50 147
Aphids 223 5 228
Pine sawflies 74 0 74
Cockchafers - imagos feeding 109 0 109
Cockchafer grubs 61 52 113
Other 170 415 585
Altogether 8221 2123 10344
Game
The information on the damage by game for 1998 were obtained from state as well as non- state subjects while they covered the area of 64 % of total area of the forests in Slovakia Total damage by game in Slovakia for the years 1998 was occurred on 706 ha and was calculated by means of new methods, which represented 8.3 mil Sk -1997 and 7.0 mil Sk -1998.
Anthropogenic injurious factors Immissions
Immissions damaged 399209 m3 of timber. Totally 359540 m3 of timber were processed, of that 81 % came to spruce, 15 % to fir and 1 % to pine.
The most affected are the stands in the counties Gelnica (34 %) and Spisska Nova Ves (21
% ). More than 3 % of affected stands are situated in the counties Stara :Cubovna, Brezno, KeZn1arok, Liptovsky Mikulas, Namestovo, Cadca and Poprad.
Forest nurseries
Injurious factors were recorded on 61.4 hectares of forest nurseries and caused the decline of 11.2 mil of seedlings and 5. 8 mil of plants.
Abiotic factors form the most important group. They caused the decline of 3.4 mil seedlings and 3.4 mil plans on 31 ha. Waterlogging and drought contributed significantly to the damage.
The second, constantly significant group of injurious factors represent fungal diseases.
They attacked an area almost 23 ha and caused the decline of 6.0 mil seedlings and 1.7 mil.
plants. Oak mildews covered the largest area (12.1 ha) but they were not the direct reason of small trees decline. As to fungal diseases beech mould (phycomycetous fungi) caused the greatest loss (3.0 mil of seedlings), seedlings damping off (2.2 mil pes) and pine needle casts (0.5 mil of seedlings and plants).
In 1998 significant damage by insects on the seedlings and the plants were recorded. The area affected reached 3. 7 ha.
The damage by rodents was found on an area of 0.6 ha. The rodents caused the decline of almost 1 mil small trees.
References
Novotny, J., Turcani, M., Zubrik, M., 1992: [Leaf-eating insect pest - occurrence, identifying, control]
Listozravy hmyz - vyskyt, kontrola, obrana. In: Vyskyt skodlivych cinitelov a ochrana proti nim v meniacich sa ekologickych podmienkach, L VU Zvolen, Zbornik referatov, s. 73-79.
Turcani M., Zubrik, M., 1997: Defoliation of forest stands by leaf-eating insect in Slovakia during period 1972- 1996. In.: Knizek, M., Zahradnik, P., Divis, K., (ed): Proceedings Workshop on Forest Insects and Disease Survey, Pisek. p. 142-144.
Varinsky, J., Brutovsky, D., Find'o, S., Kunca, A., Mailkovska, B., Novotny, J., Leontovyc, R., Longauerova, V., Pajtik, J., Turcani, M., Zubrik, M., 1998: [The report about occurrence of the most injurious factors.] Hlasenie o vyskyte skodlivych cinitelov. L VU Zvolen, ISBN 80-8853-16-8, 41 p.
Zubrik, M., 1998: System of the forest injurious factors data management in the Slovak Republic. In.:
Proceedings of First Workshop of the IUFRO WP 7.03.10 April 21-24, 1998, Ustron-Jaszowiec, Poland - Methodology of the forest insect and disease survey in central Europe. p. 69-73.
