Articles
NEGATIVE EFFECT OF FUNGICIDES USED IN PRACTICAL HOP PROTECTION AGAINST DOWNY MILDEW (PSEUDOPERONOSPORA HUMULI) ON APHIDOPHAGOUS COCCINELLIDS PROPYLEA QUATUORDECIMPUNCTATA L.
Article number
1010_12
Pages
109 – 112
Language
English
Abstract
Still increasing attention has been paid to the development of IPM systems within EU countries.
Natural enemies play a very important role in these systems.
Therefore, it is necessary to use only such pesticides, whose harmfulness is generally lower and acceptable.
Downy mildew (Pseudoperonospora humuli) is commonly controlled by fungicides applied during the season.
Nevertheless, at that time numerous aphidophagous predators, especially coccinellids are present on leaves of the treated plants feeding on aphids.
Ladybird Propylea quatuordecimpunctata L. belongs to the most important species attacking damson-hop aphid (Phorodon humuli Schrank). Fungicides, which are in current use, were tested on eggs, larvae, pupae and adults of this ladybird species to determine their real effect and convenience of their inclusion within IPM systems.
The fungicides tested in the bioassays increased the mortality rate of each developmental stage of P. quatuordecimpunctata. Adults of coccinellids were more resistant to the fungicides than the other developmental stages.
Very low susceptibility was found out after treatment with azoxystrobin.
High tolerance of adults was confirmed also in the other tested fungicides.
Eggs and larvae were generally more susceptible than adults.
Azoxystrobin again showed the lower toxicity and its convenience for IPM system as the mortality of eggs as well as larvae was the lowest.
On the contrary, copper fungicides showed commonly higher mortality.
Natural enemies play a very important role in these systems.
Therefore, it is necessary to use only such pesticides, whose harmfulness is generally lower and acceptable.
Downy mildew (Pseudoperonospora humuli) is commonly controlled by fungicides applied during the season.
Nevertheless, at that time numerous aphidophagous predators, especially coccinellids are present on leaves of the treated plants feeding on aphids.
Ladybird Propylea quatuordecimpunctata L. belongs to the most important species attacking damson-hop aphid (Phorodon humuli Schrank). Fungicides, which are in current use, were tested on eggs, larvae, pupae and adults of this ladybird species to determine their real effect and convenience of their inclusion within IPM systems.
The fungicides tested in the bioassays increased the mortality rate of each developmental stage of P. quatuordecimpunctata. Adults of coccinellids were more resistant to the fungicides than the other developmental stages.
Very low susceptibility was found out after treatment with azoxystrobin.
High tolerance of adults was confirmed also in the other tested fungicides.
Eggs and larvae were generally more susceptible than adults.
Azoxystrobin again showed the lower toxicity and its convenience for IPM system as the mortality of eggs as well as larvae was the lowest.
On the contrary, copper fungicides showed commonly higher mortality.
Publication
Authors
J. Vostrel
Keywords
natural enemies, coccinellids, Propylea quatuordecimpunctata L., damson-hop aphid, fungicides, downy mildew, toxicity, IPM
Online Articles (27)