ISSN:
1573-8248
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary In the investigations described the number of parasites (Trichogramma embryophagum hartig (var.cacoeciae marchal)) released on each tree was determined in relation to the size of the trees. Since the sectional area of the trunks, measured below the ramification, is fairly well correlated with the size of the crowns, we correlated the number ofTrichogramma to the sectional area of the trunks. In 1961 we released a number which generally corresponded to 40 wasps for each square centimeter of the sectional area of the trunks. On the trees of one orchardTrichogramma in larval und pupal stage (in eggs ofSitotroga cerealella (oliv.)) were released in small pipes closed with wiregauze; so big predators could not enter and destroy the unhatchedTrichogramma. An apparatus, named by us “Dosierungs-Trommel” (dose drum) (described and illustrated in the text) makes it possible to spray a definite amount of parasitized and unparasitized eggs (ofAnagasta kuehniella) on the crowns of apple trees. The release ofTrichogramma in this way gave better results than the release of the same amount of wasps from containers fastened to the trunks of apple trees.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02376641
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