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The investigations conducted in 1994 and 1996 concerned aphids infesting fields and neighbouring semi-natural habitats – midfield thickets with trees and the vegetation growing on the ditch margins. Aphids were caught into Moericke traps placed at the plant level. The material collected was studied to determine aphid number, dominance of individual species, similarity of dominance structure of aphid communities (Renkonen Index) and diversity of aphid communities (Shannon-Weaver Index). Aphids were collected in the field and in the natural habitats neighbouring the field. In both years black bean aphid (Aphis fabae Scop.) was either the dominant or sub-dominant species in every habitat studied. A relative species diversity of aphids occurring in semi-natural habitats was significantly higherthan that in the adjacent field. The results of these investigations indicate that the crop affects aphid fauna flying onto neighbouring midfield thickets.
The experiments were carried out in red beet crop (cv. Czerwona Kula) from 1995 to 2000. The aim of investigations was to determine the influence of mechanical weeding frequency on the species composition of aphidophagous Syrphidae in colonies of Aphis fabae Scop. in four treatments differing in ground coverage by weeds. No direct influence of weeds in red beet cultivation on species composition of aphidophagous Syrphidae in colonies of Aphis fabae Scop was observed. The dominant species occurred in all combinations. Their number depended on the number of aphids on plants, which was higher on plots maintained weed-free. The number of aphids feeding on plant was indirectly influenced by the degree of weediness, which also had influence on the occurrence of syrphid larvae. The percentage of some species (Episyrphus balteatus) was higher on plots kept weed-free while the percentage of other species belonging to genus of Sphaerophoria was higher on plots not weeded.
The studies were carried out at the Agricultural Experimental Station at Pawłowice near Wrocław, Poland, in 1998-2000. The main aim of the study was to compare the natural reduction of the black bean aphid by predators in sugar-beet crop surrounded by strips of mixture of cultivated plants, weedy strips or bare soil. The lowest number of Aphis fabae insugar-beet crop was observed at the plots surrounded by strips of mixture of Sinapis alba, Phacelia tanacetifolia and Coriandrum sativum, and at those surrounded by weedy strips. The greatest number of aphids was recorded on sugar-beet plots surrounded by bare soil. The relationships between the pest and its predators were the least stable in bare soil treatment. Significant pressure of predator activity in all treatments was shown in the first several days of the observation.
During the 2008-2009 time period, the effect of phacelia grown with broad bean on the presence of Syrphidae in colonies of Aphis fabae Scop. as well as the attractiveness of phacelia flowers for syrphid adults was researched. In A. fabae colonies, 9 Syrphidae species were collected. On plots with phacelia, less aphids and more syrphid larvae, compared to the homogenous crop, were observed. The dominant species were: Episyrphus balteatus, Shaerophoria scipta, Syrphus ribesii and Epistrophe eligans. Among the 9 species of Syrphidae collected from tansy phacelia flowers, the same species dominated as those noted in A. fabae colonies on broad beans intercropped with phacelia. Sowing plants of value to Syrphidae, such as phacelia, is probably the ideal habitat management option for early occurrence of syrphids. Such a practice result in the reduction in crop damage by aphids.
W badaniach w latach 1984-1993 w woj. olsztyńskim na bobiku odmiany Nadwiślański stwierdzono dominację mszycy burakowej Aphis fabae Scop. (71.2%). Mszyca grochowa Acyrthosiphum pisum Harris, stanowiła 26.2% populacji mszyc i ze względu na liczebność oraz późny termin pojawu nie stanowiła zagrożenia dla tej rośliny. W okresie badań wystąpiły trzy gradacje Aphis fabae, w trakcie których kolonie tego gatunku opanowywały 56-75% roślin. Liczebność kolonii miała wpływ na cechy morfologiczne roślin bobiku. Istotne okazały się różnice w wysokości roślin i liczbie strąków przy liczebności powyżej 300 osobników na roślinie oraz liczbie nasion i ich masie przy liczebności powyżej 150 osobników na roślinie. Nasilenie tego szkodnika miało więc istotny wpływ na plon nasion bobiku.
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