Comparison of the toxicity and repellency of two conventional neonicotinoids and a coconut-derived insecticide soap toward the parasitoid wasp Aphelinus mali Haldeman, 1851 | Primerjava strupenosti in odvračalnega delovanja dveh konvencionalnih neonikotinoidov in insekticidnega mila iz kokosa na krvavkinega najezdnika (Aphelinus mali Haldeman, 1851)

anglais. The parasitoid wasp Aphelinus mali,Haldeman, 1851 (Hymenoptera: Aphelinidae) is the most important biological control agent against the woolly apple aphid, Eriosoma lanigerum (Hausemann, 1802) (Hemiptera: Aphididae), which is an important apple orchards pest throughout the world. Based on the importance of using low-risk compounds to protect beneficial agents, the present study was carried out to evaluate the toxic and repellent effects of two conventional chemicals (imidacloprid and thiacloprid) and coconut-derived biopesticide soap (PalizinÒ) toward A. mali. The results of residual bioassays on apple leaf discs indicated that imidacloprid after 24 h and insecticide soap after 72 h exposure time categorized at the highest and no/little toxicity rates, respectively. Ingestion bioassays on filter papers revealed that imidacloprid and thiacloprid had moderate toxicity rate, while insecticide soap had a low-level toxicity rate. Repellency test at Y-tube olfactometer showed that the repellent effects of both chemicals were more than that of insecticide soap. It is concluded that coconut-derived soap was compatible with the parasitoid activity, and the caution should be paid when including the two neonicotinoid insecticides imidacloprid and thiacloprid for E. lanigerum management.

slovène. Parazitoidna osica krvavkin najezdnik (Aphelinus mali Haldeman, 1851, Hymenoptera: Aphelinidae) je najpomembnejši naravni sovražnik krvave uši (Eriosoma lanigerum [Hausemann, 1802], Hemiptera: Aphididae), ki je pomemben škodljivec jablan širom po svetu. Zaradi vse večjega pomena okoljsko sprejemljivejših snovi pri zatiranju rastlinskih škodljivcev, saj na ta način varujemo tudi koristne žuželke, smo v raziskavi ovrednotili toksične in repelentne učinke dveh konvencionalnih kemičnih sredstev za varstvo rastlin (imidakloprid in tiakloprid) in bioinsekticidnega mila (PalizinÒ) iz kokosa na vrsto A. mali. Rezultati poskusa na diskastih izsečkih jabolčnih listov so pokazali, da sta imela imidakloprid 24 h po nanosu in insekticidno milo 72 h po nanosu največji učinek na uši in nič ali le malo strupenega učinka na parazitoida. Prehranjevalni poskus na filtrirnem papirju je pokazal, da sta imela imidakloprid in tiakloprid zmeren toksični učinek, medtem, ko je imelo insekticidno milo zelo majhnega. Preizkusi odvračalnega delovanja snovi v Y-cevastem olfaktometru so pokazali, da so bili odvračalni učinki obeh kemikalij večji kot pri insekticidnem milu. Zaključimo lahko, da je kokosovo milo kompatibilno s parazitoidom, več pozornosti pa je potrebno nameniti, kadar za zatiranje krvave uši uporabimo oba neonikotinoidna insekticida, imidakloprid in tiakloprid.