Euphorbia bupleuroides Desf. latex as biopesticide against the red flour beetle (Tribolium castaneum [Herbst, 1797]) and khapra beetle (Trogoderma granarium Everts, 1898) | Mleček prerastolikega mlečka (Euphorbia bupleuroides Desf.) kot bioinsekticid za zatiranje riževega mokarja (Tribolium castaneum [Herbst, 1797]) in indijskega žitnika (Trogoderma granarium Everts, 1898)

anglais. Laboratory evaluation of Euphorbia bupleuroides latex as biopesticide against the red flour beetle (Tribolium castaneum) and khapra beetle (Trogoderma granarium) were evaluated at ambient temperature. The insecticidal activity of latex was determined by direct contact application. Different concentrations were prepared by dilution of 2.5, 5.0, 7.0 and 10.0 µl of latex into 0.1 ml acetone. 1 µl was pumped regularly in the thorax of different insects. The latex of E. bupleuroides showed insecticidal activity against T. granarium and T. castaneum. High levels of mortality were associated with the increase in the concentration and time of exposure as well. T. granarium adults are generally more prone to latex insecticidal effects than T. castaneum adults. After 6 days of exposure to E. bupleuroides latex, the LC50 recorded was 14.12 µl for T. granarium adults, and 14.7 µl for T. castaneum. LC90 numbers, on the other hand, were 38.8 µl for the former, and 51.44 µl for the latter.

slovène. Laboratorijsko vrednotenje mlečka iz prerastolikega mlečka (Euphorbia bupleuroides Desf.) kot bioinsekticida za zatiranje riževega mokarja (Tribolium castaneum (Herbst, 1797)) in indijskega žitnika (Trogoderma granarium Everts,1898) je bilo izvedeno pri sobni temperaturi. Insekticidna aktivnost mlečka je bila določena z neposrednim nanosom. Različne koncentracije so bile pripravljene z razredčenjem 2,5; 5,0; 7,0 in 10,0 µl mlečka v 0,1 ml acetona. 1 µl raztopine je bil previdno vbrizgan v oprsje hroščev. Mleček prerastolikega mlečka je izkazal insekticidno delovanje na oba preučevana hrošča. Velika smrtnost hroščev je bila povezana s povečanimi koncentracijami in daljšim časom izpostavitve. Odrasli osebki indijskega žitnika so bili na splošno bolj dovzetni za strupeni učinek mlečka kot odrasli osebki riževega mokarja. Po šestih dnevih izpostavitve mlečku je bila LC50 za indijski žitnik 14,12 µl in 14,7 µl za riževega mokarja. LC90 vrednost je bila za prvega 38,8 µl in 51,44 µl za drugega.