DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 3-4/1970 str. 17 <-- 17 --> PDF |
4. Brina r M.: Zivljenska kriza jelka na slovenskem ozemlji v zvezi s klimatičnimi fluktuacijama, Gozd. vestnik, 1964. 5. Ca nko v: Opasni nasekomni vrcditeli po elata, Gor. slop., Sofija, 1957. 6. Es c ho ric h K.: Forstinsektenkunde Mitteleuropas, Bd. III. Berlin, 1931. 7. Kovač e vic : Primjenjena entomologija III. dio, Šumski štetnici, Zagreb, 1956. 8. Mlinše k D.: Sušenje jelke v Sloveniji prvi isledki Gozd. vest., Ljubljana, 1964. 9. Nussli n O.: Leitfaden der Forstinsektenkunde II. Aufl., Berlin, 1913. 10. P f c f fer A.: Hmyz jako složba biocenosy jedle, Acta soc. onto. Cech. III, Prag, 1955. 11. Ratzeburg : Lehrbuch der Mitteleuropäischen Forstinsektenkunde Bd. IL, Berlin, 1895. 12. Schütz e M.: Mitteilungen über Kleinschmetterlinge, D. Ent. Zeit. BD. XXV, No 6, 1911. 13. Vajd a Z.: Moljac jelovih iglica u sastojinama Gorsikog kotara, Šum. List 9—10, 1954. 14. Vajd a Z.: Zaštita šuma, skripta, Zagreb. 15. Živoinovi ć i drugi: Zaštita četinara I. deo (od štetnih insekata). 16. Anonimus : Zaraza jelovih šuma, Šum. List, Zagreb, 1912. SILVER FIR MINERS AND DEFOLIATORS AND THEIR SHARE IN THE PROCESS OF DYING AWAY OF SILVER FIR STANDS Summary The author describes the thus far less-kown insect pests on Fir in this country, whose population density has been on the increase in recent years. On the basis of own investigations and data from the literature the author has come to the conclusion that there exist differences in the description of the Fir bud moth (Argyresthia illuminatella F. R.). Some authors (16.) state that the caterpillar´s body is red-coloured. However, through laboratory rearing and observations in nature the author has found that the caterpillar´s body is glossy and yellowish-green; the head is a very dar´k-brown and and glossy with deep boundary lines; the oral system is reddish-brown; the thoracic scutellum is small, glossy and divided, the anal scutellum is rounded, small and grey; the thoracic legs are annular, while the ventral legs (4 pairs) are almost rudimentary and of the body colour. As already stated the different descriptions by various authors are probably to be sought in the afore-mentioned species being confused with Epiblema nigricana. The damage produced by these species in recent years on the territory of the S. R. of Croatia is very extensive. In 1968, in the area of the Forest Enterprise of Fužine (forest district of Bitoraj) more tham 50Vo of Fir buds were damaged by the two abovementioned insect pests. In the same year were damaged 40"/» of buds in the Faculty demonstation forest of Zalesina in some forest districts of the Forest Enterprises of Skrad. Mrkopalj, Delnice and Krasno 30—50°/» of buds, on the southern slopes of the Zagrebačka Gora Mountain 30-Vo, and in the Fir stands of the Macelj Gora Mountain 35l:,/c> of buds. The Fir needle moth (Argyresthia fundella F. R.) ih a dngerous pest on Silver Fir producing serious damage in Fir selection forests. The population density and range of spreading of this insect pest since 1955 have steadily been on the increase. At the lower limit of the natural range of Siver Fir — inside Fir stands grown on calcareous soils — was noticed a mass outbreak of the species Semasia subsequana H. W. (syn. abiegana Dup.). An especially heavy attack by this insect pest was noticed in the area of the Forest Enterprises of Novi Vinodolski and Krasno. In addition to these regions the author found this pest also in the area of the Forest Enterprises of Otočac and Fužine, and in the Zagrebačka Gora Mountain. One shoot harboured on an average 3 caterpillars of this insect pest. All the mentioned insect pests also had appeared earlier in the forests of this country. In recent years the population density of these species has rapidly increased, damage became heavy and thus — concurrently with other unfavourable biotic and abiotic factors — the pest threatened the health condition of the Fir stands. |