Bioactive compounds and their their antifeedant activity in the cashew nut (Anacardium occidentale L.) shell extract against Bemisia tabaci, (Gennadius, 1889) (Hemiptera:Aleyrodidae) | Bioaktivne spojine v izvlečkih luščin indijskega oreščka (Anacardium occidentale L.) in njihova protiprehranjevalna aktivnost na tobakovega ščitkarja, Bemisia tabaci, (Gennadius, 1889) (Hemiptera:Aleyrodidae)

English. The present study was carried out to analyze bioactive compounds and their their antifeedant activityity in the cashew nut (Anacardiaceae) shell extract against Bemisia tabaci. Hexane was used as solvent in the extraction. The result showed that shell extract of total phenolics, flavonoids and tannins were 63.11 mg gallic acid equivalents g-1; 1.79 mg quercetin equivalents g-1; and 16.04 mg gallic acid equivalents g-1, respectively. Gas chromatography mass spectrometry (GC-MS) analyses showed that anacardic acid has the highest concentration (76.93 %) in the extract. The viscous extract of cashew nut at concentration of 0.75 % was able to inhibit the landing and provided an active role as anti-oviposition on B. tabaci. There were significantly fewer landings than after use of insecticide with imidacloprid active compound at concentration of 0.50 %, after 72 h of application. Mortalities of B. tabaci caused by extracts with concentration of 1.50 % and 3.00 % were not significantly different after 24 and 48 h of application. At concentration of 3.00 % there was no phytotoxic effect. The highest mortality of B. tabaci was obtained at concentration of 6.00 %. However, concentration of 6 % of extract caused phytotoxic symptoms on soybean leaves.

Slovenian. V raziskavi so bile analizirane bioaktivne snovi v izvlečku luščin indijskega oreščka (Anacardium occidentale L.) in njihova protiprehranjevalna aktivnost na tobakovega ščitkarja (Bemisia tabaci). Topilo za ekstracijo je bil heksan. Izvleček luščin je vseboval celokupne fenole (63,11 mg ekvivalentov galne kisline g-1), flavonoide (1,79 mg ekvivalentov kvercetina g-1) in tanine (16,04 mg ekvivalentov galne kisline g-1). Analiza s plinsko kromatografijo in masno spektroskopijo je pokazala, da je imela anakardična kislina v izvlečku največjo koncentracijo (76,93 %). Lepljiv izvleček luščin indijskega oreščka je pri koncentraciji 0,75 % preprečil usedanje vrste B tabaci in imel preko tega aktivno vlogo pri preprečevanju izleganja jajčec. Pojavnost škodljivca je bila značilno manjša kot pri uporabi insekticida z imidaklopridom kot aktivno snovjo v koncentraciji 0,50 %, 72 ur po uporabi. Smrtnost vrste B. tabaci, povzročena z izvlečkom v koncentracijah 1,50 % in 3,00 % ni bila po 24 in 48 h uporabe značilo različna. Pri 3, 0 % koncentraciji izvlečka ni bilo nobenega fitotoksičnega učinka. Največja smrtnost vrste B. tabaci je bila pri 6,00 % koncentraciji izvlečka, a je hkrati ta koncentracija povzročila fitotoksične učinke na listih soje.