Schemes of Integrated Control of the Main Defoliating Insects in Broad Leaved Stands

1984

18 Abb., 14 Tab., 10 Anh., 27 Lit. Ang., Ro, Zfsg. En

Unselbständiges Werk

3414

200016909

During period 1976-1980 were carried out researches aiming to elaborate the first schemes of integrated control of the insects: Geometridae, Euproctis chrysorrhoea, in Transilvania, Lymantria dispar and Tortrix viridana in Romanian Plain. The works were made in experimental plots formed by 3 variance-woods or series of woods in plains and phills placed in 4 ecological underregione in Transilvania and 3 underregions in Romanian Plain. In the variance 1 were applying complex experimental measures of integrated control, following a general scheme (pattern) by species of insects. In variance II intensive treatments with DDT and in variance III- (witness) no treatments. The effect of applied measures were followed by comparative assessing of the population density, natural mortality and real defoliations. Laboratory and field works to test selective and biodegradable insecticides, to replace organic chlorurate insecticides it was carried out, too. From principal results we mention here: the population density of caterpillars of Geometridae and E. Chrysorrhoea was higher in pure stands of Querceta roboris and Querceta sessiliflorae than in Querco robori carpineta fraxinetosa, respectively than in mixed stands of sessile oak, birch and small leaved lime tree, in Transilvania. Similarly in Romanian Plain Querceta cerris and Querceta roboris stands were more defoliated by L. dispar than Querceta robori carpineta fraxinetosa stands. In pure stands of oak pedunculate and sessile oak when ecological degradation is more advanced and where we were applying silvicultural special measures (underwoods, etc.) biological (birds, ants, etc.) and physical-mechanics measures against Geometridae and e. chrysorrhoea, density of populations were diminshed at low levels and the state of ecosystems was improved. Treatments using microbiological substances, physical-mechanics measures and chemical selective insecticides have reduced the population density of L. dispar, but not conclusive, because of more frequently previous treatments with DDT in the south of country. We have identified 22 species of poliphagous parasites and predatores which will be used in integrated control. Differencies among variances with integrated control and chemical control and witness will be more obvious in the future. Finally we have elaborated 10 schemes of integrated control as following: 5 schemes for the main species of Geometridae, 3 schemes for E. chrysorrhoea, 1 for L. dispar and 1 for T. viridana. Practical applying of integrated control schemes must be permanently.