The Influence of Nutritions in Fir Tree Needles to the Change of Population Density of Fir Tree Needle Moth (Argyresthia fundelly F.R. Tineidae, Lepidoptera)

1988

S. 227-261

5 Abb., 6 Tab., 9 Lit. Ang.

Unselbständiges Werk

200011990

A lot of authors has been described the causes of the mass appearance of harmful insects, especially about relation of biochemical changes and the increasing number of miners and depholiators (Schwenke, 1968). Our observations during the investigating of moth and his gradiations in the past period are also close with the conection of biochemical process in the plant. From that reason we habe begin the investigations of nutritious status of fir treeby the pholiar analysis of needles especially the content of minerals. The res ults we find were not satisfactory, so we continue with determinating the content of carbonhydrats (sacharosis, directly reduced sugars), and the content of amino-acids in needles and in aaterroillars of miners. The changes of the population density of fir tree needle moth Argyresthia fundella F.R. were observed parallely on some chosen experimental surfaces. Surfaces were chosen in natural fir trees areas of Gorski Kotar (Klana, Gerovo, Fuzine) in SR Croatia. The results of investigating the percentage of the carbohydrates content on the green mass of fir tree needles during the vegetation season shows on some lowfullness. The renewal of amino-nitrats in old and in new needles flows with differentintensity. The oscilations in the percentage of sugar content are conditioned by the period of year and with the variability of samples needles from various localities, and their manifestations are the strongest in summer period, in thestage of the most intensive growth of biomass and breathing. In that period ha ve been noticed the biggest vacillations of sacharosis content, once or twice bigger than usually. When the content of saccharosis is decreasing, the content of dry material is increasing in needles. Also the content of soluble carbohydrats increases and it is favourable for the development of fir tree needle moth(Argyresthia fundella F.R.). The oscilations of amino acids in percentage are conditioned with absorption of soluble and with protein connected arginin and oscilates in months (April, June). The absorption of proteins decreases in June (summer months), so the absorption of carbohydrates. This facts became skilled in that the critical point for the development of fir tree needle moth (caterpillar) doesn't represent the amount of found aminoacids, proteins in nutritious but their ussage. It is probable that the change of materials in the organism depends of the protein hydrolysis.