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The side‐effects of plant extracts and metabolites of Reynoutria sachalinensis (F. Schmidt) Nakai and conventional fungicides on the beneficial organism Trichogramma cacoeciae Marchal (Hym., Trichogrammatidae)
Author(s) -
Hafez M. B.,
Schmitt A.,
Hassan S. A.
Publication year - 1999
Publication title -
journal of applied entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 60
eISSN - 1439-0418
pISSN - 0931-2048
DOI - 10.1046/j.1439-0418.1999.00379.x
Subject(s) - biology , fungicide , horticulture , botany , toxicology
The aim of this study was to investigate the side‐effects of plant extracts (plant strengthener with resistance inducing properties) and conventional fungicides on the egg parasitoid Trichogramma cacoeciae Marchal. Two plant extracts and one metabolite from Reynoutria sachalinensis (F. Schmidt) Nakai (crude water extract (Rey‐crude & reg;), which is used for the control of powdery mildew and other diseases, a methanolic fraction of this extract (Rey‐meth & reg;) and the anthraquinone plant constituent (Physcion & reg;), as well as four fungicides (Thiram & reg;, Dithane & reg; M45, Euparen M & reg; and Kumulus & reg;) were tested. Adults of T. cacoeciae of uniform age were exposed to fresh dry film of the compounds and the percentage reduction in parasitism compared with water‐treated controls was calculated. The results of experiments using the highest recommended concentrations sprayed on glass plates showed that the preparations greatly differed in their effect on the parasitoid. All of the conventional fungicides tested were found to be harmful. In contrast, Rey‐crude and Physcion were harmless to T. cacoeciae , whereas the fraction Rey‐meth was slightly harmful. In further experiments the side‐effects of the plant protection agents on T. cacoeciae were compared when sprayed at different concentrations either on glass plates or on vine leaves. The results confirmed the findings of the first trials but showed that side‐effects of the compounds Dithane M45 and Euparen M were less toxic when applied to vine leaves.